OBD Scanner and ECU Tuning Software

TOAD Auto Diagnostics

The TOAD system is a suite of car diagnostic tools and tuning software. Loaded with all the same functions used by dealerships and constantly updated by expert engineers, so youll always be supported. The TOAD system can be loaded onto your laptop and then connected directly to your car. No extra expensive scanners or equipment is required. Take complete control of your car while parked in your garage or leave your laptop plugged in while driving for even more detailed readouts. When you purchase the TOAD system you will receive a suite of diagnostic and tuning software DVD. This DVD includes all the same functions as original dealer diagnostic tools, which normally are not available to the public. The DVD is fully ready to be installed onto your computer and includes, OBD-1 software, OBD-2 software, ECU tuning and editing software, manuals, emission testing decryptors, and ECU map files. Continue reading...

Total OBD & ECU Auto Diagnostics Summary


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A3 Obd Ii standard fault codes

A principal aim of this book is to show readers that there are significant amounts of technology that are common to all computer controlled automotive systems. In reaching this conclusion it is natural to enquire why, when there is so much common ground, there are so many different approaches to diagnostics. It has long been acknowledged that the 'profusion' of diagnostic trouble codes, access to data, different interfaces between scan tools and ECMs, and other details, have made the work of service technicians more difficult than it perhaps needs to be. This acknowledgement of 'difficulties' at the user end of a vehicle's life cycle has resulted in various standards being incorporated into OBD II, and similar standards are likely to feature in EOBD. The standard diagnostic plug (SAE J 1962) and the format of DTCs (SAE J 2012) have been covered in this book. The following list of standard diagnostic trouble codes is derived from SAE J 2012, by courtesy of Robert Bosch Ltd. It is...

412 Obd Ii Type Diagnostic Equipment

Much of the diagnostic capability that is known as OBD II has been in use for some time. The main effect of the OBD II legislation seems to have been to focus attention on the desirability of standardization, particularly in the areas of means of access to diagnostic data on vehicle systems and the availability of supporting documentation. This means that some of the techniques described under this heading will, in some cases, be available on non-OBD II systems. Firstly the principal features that relate to OBD II are outlined. This is followed by a description of the equipment and its diagnostic functions. The principal features are as follows. As far as actual practice is concerned, the user merely prepares for the test. The above procedure takes place automatically via the control buttons on the scan tool. Some of the main points about the OBD II test tool are that it must Fig. 4.4 The Bosch KTS 300 pocket system tester Fig. 4.4 The Bosch KTS 300 pocket system tester Figure 4.4...

Use of exhaust gas concentration sensors

Surface ionization detectors are also a possible future solution for OBD purposes, but for the time being they suffer from considerable drawbacks. NO* sensors are still under investigation and they have been used in the literature in a limited number of cases for OBD purposes.

Ford Motor Co Ford France SA Ford Werke AG Ford Motor Co Canada Ford Motor Co

Interrogation routine after steady-state conditions and a window of air fuel, speed load opportunities are met. These conditions are described in the California Air Resources Board (CARB) regulations designated OBD II. The criteria are specified in these regulations, which are incorporated herein by reference (see Introduction)

69 Electronic unit injectors

In case of any sensor or actuator malfunction, the ABS warning light located in the combination meter will light up to alert the driver that a malfunction has occurred. The ECU will also keep the codes of the malfunctions in memory. For details on the check procedure, see the GS300 Repair Manual (Pub. No. RM 352EI), The description of the diagnostic trouble codes is identical to that of the LS400. K Diagnostic Trouble Code A K Diagnostic Trouble Code A

583 Onboard Monitoring Of The Catalytic Converter

The USA OBDII and impending European legislation requires that vehicle emissions systems are equipped with the facilities to illuminate a warning lamp (malfunction indicator lamp or MIL) should the catalytic converter cease to function correctly. In order to meet this requirement it is current practice to fit a second oxygen sensor downstream of the catalyst, as shown in Fig. 5.34.

1222The Weber electronic control system

The Weber multi-point injection system is in many respects similar to the Bosch systems already described, but its electronic control is totally different and also exercises control over the ignition timing. Injection timing is calculated on the basis of the throttle position, absolute temperature and pressure of the air in the induction manifold, the instantaneous speed of the engine and rotational position of the crankshaft. All these inputs are taken into account together with other data in the memory of the electronic control unit, including an engine performance map and the variation of volumetric efficiency with speed. Compensation is effected for variations in the voltage of the battery output. A more detailed description can be found in Automotive Fuels and Fuel Systems, Vol. 1, by T.K. Garrett, Wiley.

121 Basic considerations

The pump must deliver the fuel reliably and continuously (without pulsation) and, in most systems, at a closely controlled constant pressure. Injectors must be capable of metering and delivering the fuel in the form of a fine spray into the manifold, without either pre- or post-injection dribble. Sensitivity of the electronic control unit is critical. So also are both the accuracy of the activators that it controls and the sensitivity of the sensors that signal to it the engine parameters on the basis of which it exercises control. These parameters include some or all of the following mass air flow into the engine, ambient

1216 Bosch LHJetronic system

All components of the LH are virtually identical to those of the L-Jetronic system, except for the electronic control unit and the substitution of a hotwire, air-mass-flow meter (Section 12.10) for the volume-flow meter. A major advance made more easily feasible by the use of the hot-wire system is the use of a digital instead of analogue electronic control system, the former being potentially much more flexible. Other advantages of the LH system are negligible resistance to air flow and absence of moving parts.

1017 Active suspension

For an active suspension to operate effectively various sensors are installed around the vehicle to monitor changing driving conditions the electrical signals provided by these sensors are continuously fed to the input of an electronic control unit microprocessor. The microprocessor evaluates and processes the data supplied by the sensors on the changing speed, loads, and driving conditions

3914 Traction control in general

These systems have to override driver control of the throttle pedal. Therefore there can be no mechanical linkage between the pedal and the throttle or, for diesel engine driven cars, the governor control lever. Instead, a drive-by-wire system is employed, in which a pedal position sensor translates throttle pedal angle into an electric signal. This, together with other signals from, for example engine temperature and engine speed sensors, is transmitted to the electronic control unit. These signals are then translated into a control voltage for an electric servo-motor that actuates the throttle valve or governor control level on the engine. Wheel spin is monitored on the driven wheel on each side of the vehicle. If one or both wheels spin, combinations of brake, throttle and ignition controls can be employed. In some simpler torque control systems, either the brakes or throttle valve control are used alone to stop wheel spin but response times can be so long as to cause unacceptable...

366 Structural safety and air bags

Fig. 36.12 Top, mechanically actuated bag firing mechanism bottom, electrically actuated alternative. The latter has the advantages of greater compactness of the parts that may have to be accommodated in the steering wheel hub and the sensors and electronic control unit can be sited in the most appropriate positions Fig. 36.12 Top, mechanically actuated bag firing mechanism bottom, electrically actuated alternative. The latter has the advantages of greater compactness of the parts that may have to be accommodated in the steering wheel hub and the sensors and electronic control unit can be sited in the most appropriate positions

88 Supplementary restraint systems SRS

System normally uses signals from two sensors a 'crash sensor' and a 'safing sensor'. The safing sensor is activated at a lower deceleration than the crash sensor (about 1.5 g less) and both sensors must have been activated in order to trigger the supplementary restraint system. The safing sensor is fitted to reduce the risk of a simple error bringing the airbag into operation. Both of these sensors may be fitted inside the electronic control unit which, in some cases, is known as a diagnostic and control unit (DCU) because it contains the essential self-diagnosis circuits in addition to the circuits that operate the SRS. Figure 8.20 shows the layout of a supplementary restraint system on a Rover Mini.

3911 The reference speeds

On the basis of the signals it receives from wheel-speed sensors mounted on both the driven and undriven wheels, the electronic control unit calculates a series of reference speeds, Vref. each of which is the datum on which the next stage in the succession of pressure holds, releases and re-applications is based. On the assumption that the clutch is disengaged when the brakes are applied, this reference speed is based, at moderate speeds, on the signals from the fastest rotating wheel. When, however, ABS is in operation during emergency stops at higher speeds, the reference speeds are extrapolated directly from that at the beginning of the ABS cycle.

2112 Data Buses For Different Applications

A two-wire CAN bus that can operate at high data transmission speeds of up to 500 kbaud (500 000 bits s) (Fig. 2.13). Fig. 2.13 The CAN bus system The twisted pair of the CAN bus system minimizes electrically-initiated interference and virtually eliminates the possibility of messages becoming corrupted.

244 Programmable Logic Controller

Production units are destined to use a custom-engineered microprocessor unit based on a Siemens Thompson C167 CAN bus processor, which is becoming a standard in the European and American car industry. This unit must represent one of the toughest design challenges. To convert low voltage, heavy current into higher voltage with galvanic isolation, ultra-low current ripple and high efficiency. Many solutions have been analysed, although this one offers the best combination of characteristics. Figure 2.19 shows electronic system circuits.

726 Bosch VP44 radial plunger type pump

How Vp44 Injection Pump Works

The VP44, Fig. 7.55, is described by Bosch as a high pressure electronically controlled radial plunger type pump. Its housing is divided by a diaphragm into two chambers. One, at fuel lift pump delivery pressure, accommodates the drive shaft and all the components mounted on it. The other, at a much higher pressure, houses the distributor head and shaft. In the base of the pump housing is the device for regulating the timing of the start of injection, together with the pulse valve which influences the timing device by modifying the hydraulic pressure applied to its piston. Mounted on top of the housing is the pump control unit (PCU), which operates in association with the engine electronic control unit (ECU).

RK 280 engine details

Governor, the engine is served by a digital engine management system which controls its operation and communicates via a CAN bus link to a set of intelligent cylinder control modules that drive the pump and injector solenoids. The system dictates the fuelling, timing and pressure base upon pre-set mapped information.

1171 Hydromechanical antilock brake system ABS suitable for cars SCS Lucas Girling

Lucas Girling Brake System

Speed sensor and excitor (Fig. 11.40) The speed sensor uses the variable reluctance magnetic sensing principle, whereby a cylindrical permanent magnetic core with a coil wire wound around it, mounted on the stationary hub carrier, axle casing or back plate, produces a magnetic field (flux) which overlaps the rotating excitor ring. The exci-tor may be of the tooth ring or rib-slot ring type attached to the rotating wheel hub or drive shaft. A number of teeth or slots are arranged radially which, with the speed of rotation of the road wheel, determine the frequency of the signal transmitted to the electronic-control unit. As the wheel and excitor revolve, the teeth and gaps or ribs and slots of the excitor pass through the magnetic field of the sensor. The coil wrapped around the mag- The road wheel speed measured by the speed sensor provides the wheel deceleration and wheel acceleration signals for the electronic-control unit. The merging and processing of the individual wheel speed...

294 Alfa Romeo Selespeed transmission

When he takes his foot off the brake pedal, the vehicle moves away. Operation of the clutch and throttle is effected by the electronic control unit, on the basis of signals it receives from sensors detecting the throttle position, engine torque and which gear is selected. Once the speed

1226 Rover throttle body injection and ignition control

Single Point Injection System

Electronic Control Unit Electronic Control Unit An ignition timing map is programmed into the memory of the electronic control unit (ECU), which regulates both the ignition and fuel metering. Short circuit protection is incorporated, and powerful diagnostic facilites store intermittent fault data. Either the Rover Microcheck or Cobest hand-held diagnostic units can be plugged into a separate connector, without disturbing the ECUs main connector. The ECU also controls both an electric heater at the base of the manifold riser and a stepper motor for regulating idle speed.

1225 The Multec multipoint system

In principle, the GM Multec multi-point system resembles the Bosch Motronic, Sections 12.17 to 12.21. To avoid repetition, therefore, only a few brief comments will be made here. It is a complete engine-management system, Fig. 12.38, regulating EGR, ignition, fuelling, overrun cut-off, air flow control, including during idling, and open, or closed-loop control over emissions. However, the ECM, is served by signals from the throttle position indicator and manifold pressure and temperature sensors, and meters the air flow on the speed-density principle, so the rate of fuelling is regulated in relation to the computed mass flow. On the other hand, mass flow air metering with a hot wire anemometer is an optional alternative. Among the features of the system are on-board diagnostics, back-up fuel and ignition circuits, and an assembly line diagnostics link. Another option is either direct or distributor ignition timing.

3816 Mercedes Benz Brake Assist BA

Electronic Brake Assist

From Fig. 38.30, it can be seen that the brake actuation unit comprises a fairly conventional brake servo with the addition of a pedal travel sensor, a solenoid valve which in fact is the air valve, an electronic control unit, and a brake release switch. So long as the brakes are inactive, induction manifold depression acts equally on each side of the diaphragm. When the driver moves the brake pedal, the push rod opens the air valve, applying atmospheric pressure to the chamber on the right in the illustration. This moves the diaphragm to the left, until the air valve is closed. Thus, without BAS, the pressure in the hydraulic brake system is at all times proportional to the pedal travel.

298 Leyland continuously variable transmission

The really clever part of the whole transmission is the system for controlling the ratio of the variator. Central to this control system is the microprocessor, a significant feature of the demand on which is that it is continuous. In contrast, a microprocessor in a conventional automatic transmission springs into action only when a gear shift is called for. Consequently, the CVT has a 16-bit microprocessor with 8 kbyte of software. It actuates an electro-hydraulic valve controlling a low pressure system for loading the variator axially in proportion to the torque transmitted, as well as for steering the rollers and actuating the clutches. The three main inputs to the electronic control unit are driver demand and the speeds of the engine and of the vehicle.

Selfdiagnosis and fault codes

Whilst a computer controlled system is operating normally, the processor is constantly monitoring the electrical state of input and output connections at the various interfaces of the ECM. This monitoring (reading) of the inputs and outputs occurs so that the instructions that the computer processor has to perform, such as to compare an input value with a programmed value stored in the ROM, means that the ECM is ideally placed to 'know' what is happening at many parts of the system that is connected to it. If, for example, a throttle position sensor is producing a reading that does not tie in well with engine speed and load signals that the ECM is reading, the software (program) in the ROM can be written so that an alternative section of program is followed (loop), and a predetermined code can be stored in a section of working memory (RAM) that is allocated for this purpose. The piece of coded information that is stored is known as a 'fault code' or 'diagnostic trouble code' (often...

343Vpc Vltc Vplc and VET systems

Fig. 3.29 (a) Honda variable valve timing system. In the section on the left, the two outer rocker arms are actuated by their cams, while the central one is idling. Shown on the right is the condition when electronic control unit (ECU) has signalled a solenoid to open a valve allowing oil under pressure to push the three-piece hydraulic plunger to the right, locking all three together. In this condition, the central cam, because it is higher than the other two, actuates the valves. In the graph (b) the central curve shows how the ECU varies the change-over point with speed. The upper lines in the two other pairs of curves represent operation with and the lower ones without change-over. Fig. 3.29 (a) Honda variable valve timing system. In the section on the left, the two outer rocker arms are actuated by their cams, while the central one is idling. Shown on the right is the condition when electronic control unit (ECU) has signalled a solenoid to open a valve allowing oil under pressure...

Diagnostic tools and equipment

As stated in Chapter 3, the control computer ECM has considerable self-diagnostic power and the DTCs that may be stored in its memory are a valuable source of diagnostic information. The fact that the ECM processor is constantly monitoring inputs and outputs, means that the data that it uses can also be used by any other computer that is using the same protocols (language). This is a facility that microprocessor-based diagnostic tools possess and it enables them to be used to read system behaviour while the system is in operation and also to capture and save data for detailed analysis. In order for this to happen the ECM must be equipped with a suitable serial diagnostic interface that will permit two-way communication between the test equipment and the ECM (Fig. 2.5 shows the general principle of a serial data connector). As pointed out in Chapter 3, there is movement towards widespread adoption of the USA OBD II and California Air Resources Board (CARB) standard, but this is not...

Test Instruments Connected To These Pins

The Bosch KTS 500 is an example of a recent development that puts even greater diagnostic power at the disposal of the technician. This instrument is plugged into the diagnostic connector as shown in Fig. 4.14. Fig. 4.14 The Bosch KTS 500 control unit diagnosis tester Fig. 4.14 The Bosch KTS 500 control unit diagnosis tester

640 Bosch electronic controls for injection pumps

Bosch Edc Pump Sensor

A set of sensors transmit, to the electronic control unit (ECU), the data it needs for regulating the current through the solenoid, Fig. 6.42. In operation, the control rod moves axially. Equilibrium is maintained between the forces Fig. 6.41 One of the Bosch electronic control units for in-line diesel injection pumps. The position of the stop for the rack, or control rod, is varied by an electronically controlled solenoid acting against the return spring. A rack position sensor is mounted immediately above the end of the rack and the return spring assembly and the pump speed and timing sensor is below, on the end of the pump shaft Fig. 6.41 One of the Bosch electronic control units for in-line diesel injection pumps. The position of the stop for the rack, or control rod, is varied by an electronically controlled solenoid acting against the return spring. A rack position sensor is mounted immediately above the end of the rack and the return spring assembly and the pump speed and...

Anticlockwise rotation of the steering wheel turning left low speed Figs 938b and 939b Rotating

Electronic control unit (ECU) When the vehicle is stationary or moving very slowly and the steering wheel is turned to manoeuvre it into a parking space or to pull out from a kerb, the electronic speedometer sends out its minimal frequency signal to the electronic control unit. This signal is processed and a corresponding control current is transmitted to the electro-hydraulic transducer. With very little vehicle movement, the control current will be at its maximum this closes the transducer valve thus preventing fluid pressure from the pump reaching the reaction valve piston device and for fluid flowing to and through the cut-off valve. In effect, the speed sensitive rotary control valve under these conditions Anticlockwise rotation of the steering wheel (turning left high speed) (Figs 9.38(c) and 9.39(b)) With increasing vehicle speed the frequency of the electronic speedometer signal is received by the electronic control unit it is then processed and converted to a control current...

2810 Porsche Tiptronic electronic control system

Holzkessel Hersteller

The electronic control unit, which is supplied by Bosch, has an 8-bit microprocessor with an external 32 kB EPROM memory. It has 42 inputs and outputs, and all control unit interfaces are short circuit resistant and protected also against incorrect connection. The unit is screened against interference by external electromagnetic fields. A diagnostic program monitors internal voltages and carries out plausibility checks on groups of input signals. It detects and records even sporadic failures within the system. If appropriate, it selects substitute functions, illuminates a warning lamp on the fascia, and stores all the relevant information ready for transmission to the diagnostic equipment available in all Porsche dealerships. Manual control is obtained by moving the lever laterally, from the D position, into a longitudinal gate parallel to that for automatic control, Fig. 28.18. This manual gate has only two position, + and - for changing up or down respectively. The lateral movement...

Unequal weight distribution levelling control

Is accelerated rapidly, particularly when pulling away from a standstill, there is a proneness for the body due to its inertia to hold back whereas the propelled wheels and unsprung part of suspension tend to move ahead of the interlinked body. This results in the body tilting backwards so that it squats heavily on the rear axles and wheels (see Fig. 10.124(g)). To correct this ungainly stance when the car is being accelerated, fluid is quickly displaced from the accumulator and pump through the open levelling control valve into the rear strut actuator cylinders this levels the body longitudinally (see Fig. 10.124(h)). Once the acceleration sensor detects a reduction in acceleration, the electronic-control unit signals the levelling control valve to return the excess fluid trapped in the rear actuator cylinders back to the reservoir so that under steady driving conditions the body remains parallel to the road. 10.17.4 Semi-active hydro gas electronic controlled suspension system (Fig....

97 Rack and pinion electric power assisted steering

Basics Rack And Pinion Steering

An electronic control unit which is a microprocessor takes in information from various electrical sensors and then translates this from a programmed map into the required steering assistance to be delivered by the servo electric motor. Mechanical power is supplied by a servo electric motor which is able to change its polarity so that it can rotate either in a clockwise or anticlockwise direction as commanded by the direction of steering turn, the drive being transferred from the output pinion shaft via a warm gear and warm wheel. The large gear reduction ratio provided with this type of drive gearing enables the warm wheel to rotate at a much reduced speed to that of the warm gear and enables a relatively large torque to be applied to the output pinion shaft with a moderately small electric motor. output shafts by the slide-sleeve movement, this is then converted into an electrical signal via the interlinked rotary potentiometer sensor. Engine and road speed sensors enable the...

Electronic Fuel Injection

The Lucas Bryce system comprised a single-cylinder, electronically-controlled plunger pump which supplies fuel to the injector via a high pressure pipe and is driven directly from the engine camshaft alternatively, an electronically-controlled unit injector may be used (the choice depends on the engine design). Fuel control is achieved by solenoid valves operated from the electronic control unit which Delphi Bryce calls the smart drive unit (SDU). Lucas Electronics also developed an engine governor, called a control and protection card (CPC) in some cases, however, the governor is supplied by specialist manufacturers or the enginebuilder.

4012 The Nissan Super HICAS system

The latest version of the Nissan system, Fig. 40.16, is a good example of how the principles of rear wheel steering are applied in practice. Essentially it comprises an electronic control unit (ECU), which controls a solenoid valve, a hydraulic pump and a power cylinder. An optical sensor mounted on the steering column transmits to the ECU signals representing steering direction and angle, and the rate of change of steering angle, and it receives signals representing vehicle speed from an electric speedometer, Fig. 40.17. Other sensors inform the ECU whether the clutch is engaged, that the gear selector lever is not in the neutral position and the brake stop lamp is off, in other words that the vehicle is actually being driven. Incidentally, other factors that influence steering include front-rear braking distribution and displacement of the suspension linkages.

862 Secondary Air Injection

Whenever the ECM detects the conditions that cause it to record a diagnostic trouble code (fault code), the sensor readings (variables) and the vehicle operating conditions that exist at the time of the occurrence of the fault, are stored in a section of ECM memory. The format in which this information is presented at the diagnostic tool is known as a 'freeze frame'. The information contained in the freeze frame is read out by the scan tool and is of use in diagnosis. Freeze frames can be overwritten if a diagnostic trouble code of higher priority, in the same system, occurs later. One of the problems that has confronted independent garages that wish to repair and maintain vehicles equipped with computer controlled systems, has been the lack of information about diagnostic trouble codes (fault codes). To some extent this lack of DTC information is overcome by the companies listed in the Appendix who publish volumes of DTCs for many different types of vehicles. A quick glance through...

Monitoring and diagnosing the efficiency of catalytic converters

The present book refers to on-hoard (OBI)) or non-OBD monitoring methods of the condition of a catalytic converter installed in the exhaust pipe of an internal combustion engine vehicle. The term non-OBD means methods of monitoring taking place in workshops by specialized technicians and special equipment. The term on-board means methods of monitoring taking place during driving of the vehicle and being executed by the control unit of the vehicle. Onboard methods are the most recent ones and in some legislatures their application has become a statutory requirement. The first generation of on-board diagnostics (OBD I) was introduced by the state of California in all vehicles sold by 1990. This first generation OBD did not monitor many important emission control subsystems, such as the evaporative emissions system, the secondary air injection and the catalytic converter Table 4 Emission reduction measures to be monitored by on-board diagnostics Table 4 Emission reduction measures to be...

125 Some other injectors

The layouts of the injectors for the Bosch L-, LH-Jetronic and Motronic systems are all broadly similar, Fig. 12.7. Because their pintle-type valves and armature assemblies, with their return springs, are inevitably heavier than the valves in the K- and KE-Jetronic systems, their solenoids, which open them for timed periods, are energised by electric pulses triggered by the electronic control unit. The valve lift is about 0.1 mm and the release time is between 1 and 1.5 ms.

1215 Bosch LJetronic system

In the L-Jetronic system, Fig. 12.21, the electronic control unit performs the same function as the mixture control unit of the K system. It does this, however, by controlling the duration of opening of the solenoid-actuated valves in the injectors. The advantage of electronic control is that there are fewer mechanical components liable to wear or to stick and thus to malfunction. Moreover, ultimately, more accurate control is possible because the system can be made more easily to respond to a wider range of variables than when a mechanical system is used. The start of each injection pulse is signalled to the electronic control unit by the contacts in the ignition distributor. However, the control unit has to 1 Electronic control unit

710 Traction control system

To achieve this traction control an electronic control unit (ECU) is used which receives signals from This traction control system consists of an electric motor driven hydraulic pump which is able to generate brake pressure independently to the foot brake master cylinder and a pressure storage accumulator a traction boost unit which comprises a cylinder housing, piston and poppet valve, the purpose of which is to relay hydraulic pressure to the appropriate wheel brake caliper and at the same time maintain the traction boost unit circuit fluid separate from the foot brake master cylinder fluid system a pair of traction solenoid valve units each having an outlet and return valve regulates the cut-in and -out of the traction control an electronic control unit (ECU) is provided and individual wheel speed sensors which monitor the acceleration of both driven and non-driving wheels. Should the speed of either of the driven wheels exceed the mean wheel speed of the non-driven wheels by more...

Mazda Motor Corporation

Cylinder Row And Cylinder Bank

In addition, the electronic control unit controls a warning lamp to signal critical deterioration of the secondary catalytic converters, as well as critical deterioration of the main catalytic converter. Air fuel ratio control is accomplished as the electronic control unit reads each signal. The electronic control unit calculates the amount of air to be supplied into the combustion chamber for each cycle based on an air (low rate signal and an engine speed signal. Subsequently, the electronic control unit calculates, based on the calculated amount of air, a basic fuel injection rate at which the fuel injection valve injects fuel into the combustion chamber. Thereafter, the electronic control unit decides whether or not the engine is put in engine operating conditions for the air fuel ratio feedback control. That is, the air fuel feedback condition is fulfilled when the engine operates in a specific engine operating range defined by throttle opening, which represents engine load, and...

961 Steering desirability

An electronic control unit microprocessor takes in speed frequency signals from the electronic speedometer, this information is then continuously evaluated, computed and converted to an output signal which is then transmitted to the hydraulic transducer mounted on the rotary control valve casing. The purpose of this transducer is to control the amount of hydraulic pressure reaching the reaction-piston device based on the information supplied to the electronic control unit.

621 Mapcontrolled Drive Management

BMW researchers2 have shown the possibility of challenging the fuel consumption levels of conventional cars with parallel hybrid levels, by using map-controlled drive management, Fig. 6.3. The two-shaft system used by the company, seen at (a), uses a rod-shaped asynchronous motor, by Siemens, fitted parallel to the crankshaft beneath the intake manifold of the 4-cylinder engine, driving the tooth-belt drive system as seen at (b) overall specification compared with the 518i production car from which it is derived is shown at (c). The vehicle still has top speed of 180 kph (100 kph in electric mode) and a range of 500 km relative performance of the battery options is shown at (d). Electric servo pumps for steering and braking systems are specified for the hybrid vehicle and a cooling system for the electric motor is incorporated. The motor is energized by the battery via a 13.8 V 50 A DC DC converter. The key electronic control unit links with the main systems of the vehicle as seen at...

1218The electronic ignition control

An indication of how the electronic control unit regulates injection and ignition simultaneously can be gleaned from Fig. 12.28. To keep the breakaway and release times of the injection valves as short as possible without using current-limiting resistors, the current to them is limited by a special integrated circuit in the electronic control unit. For a six-cylinder engine, for instance, the valve opening current is 7.5 amp and, at the end of the injection period reduced to a holding current of 3.5 amp.

1018 Electronic controlled pneumatic air suspension for on and off road use

Compressor pressure switch A compressor pressure switch monitors the reservoir tank air pressure and provides a signal to the electronic-control unit (ECU) to switch the compressor's electric motor on when the pressure drops below 7.5 bar and to switch it off as the pressure reaches 10 bar.

10171 Description and application of sensors

Secondary windings connected in series in opposition to each other. An alternative input supply voltage is applied to the primary winding this produces a magnetic flux which cuts through the secondary winding thereby inducing an alternative voltage into the secondary winding. The difference between the voltage generated in each secondary winding therefore becomes the output signal voltage. With the non-ferromagnetic soft iron armature bar in the central position each secondary winding will generate an identical output voltage so that the resultant output voltage becomes zero. However when the armature (attached to the lower suspension arm) moves up or down as the body height changes the misalignment of the soft iron non-ferromagnetic armature causes the output voltage to increase in one winding and decrease in the other, the difference in voltage increasing in direct proportion to the armature displacement. This alternative voltage is then converted to a direct voltage before entering...


If we take the above example of the coolant sensor and consider the implications of the code that tells us that there is a low coolant temperature and consider what might be involved, we should see that reading the DTCs is often one of several steps on the path to diagnosis and repair of defects. The output signal from the sensor is conveyed to the ECM via a cable which probably has at least two connectors on it as shown in Fig. 3.23. What the ECM reads is what is presented to it through the sensor circuit. If there is a defect in the sensor circuit, such as high resistance, this could cause the ECM to receive a voltage reading that represents the coolant temperature, which is lower than the actual coolant temperature. This is true of practically all sensors, actuators and related circuits that form part of automotive computer controlled systems which the control computer (ECM) relies on for its operation. The DTCs are thus an aid to fault diagnosis they rarely state exactly what the...

Fault Code 2 6

The above descriptions give a reasonable overview of the methods of 'reading' diagnostic trouble codes. I now propose to look at more recent developments that have arisen from legislation and advances in technology. data and it is anticipated that Europe will follow a similar path in the near future. As the USA has a major influence on events in technology, it is to be expected that their developments will have an effect on vehicle technology in Europe and elsewhere. There is plenty of evidence to show that this is the case and readers should benefit from a review of some recent developments, such as on board diagnostics (OBD). The term on board diagnostics refers to the self-diagnosing capabilities that are carried in the computers on the vehicle, and the aids that are provided to make the diagnostic data available to authorized users. Off-board diagnostics is equipment such as scan tools, oscilloscopes and other test equipment. In most cases both types of equipment are required for...

Charging Stations

During EV charging, the charger transforms electricity from the utility into energy compatible with the vehicle's battery pack. According to Society of Automotive Engineers (SAE), the full EV charging system consists of the equipment required to condition and transfer energy from the constant-frequency, constant-voltage supply network to direct current. For the purpose of charging the battery and or operating the vehicles electrical systems, vehicle interior preconditioning, battery thermal management, onboard vehicle computer, the charger communicates with the BMON. The BMON dictates how much voltage and current can be delivered by the building wiring system to the EV battery system.


The data logger aspect of test equipment capability permits the test equipment to store selected data that the test equipment 'reads' through the serial data diagnostic connector of the ECM. It is particularly useful for aiding the diagnosis of faults, such as an unexpected drop in power that occurs during the acceleration phase. When the test equipment is connected, and proper preparations have been made for a road test, the vehicle is driven by a person who should be accompanied by an assistant to operate the test equipment (for safety reasons). With the test equipment in 'record' mode, the vehicle is driven in an attempt to re-create the default condition and when the 'fault' occurs the test equipment control button is pressed. From this point, data from just before the incident and for a period after is recorded. The stored data can then be played back, on an oscilloscope screen, or printed out later for analysis in the workshop. Figure 7.43 shows an example of live data that was...


For the control of the engine operation, there is provided an electronic control unit (ECU) having an input terminal to which an ignition coil composed of a boosting transformer and an igniter constituted by a power transistor for interrupting electric conduction through a primary winding of the ignition coil is connected. An idle switch which serves to detect the idling operation state of the engine in which the throttle valve is fully closed is provided integrally with the throttle sensor, wherein the output signals D and < p of both the idle switch and the throttle sensor are supplied to the electronic control unit. Supplied additionally to the electronic control unit are an output signal T of a thermistor-type water temperature sensor which is employed for detecting the temperature T of the engine cooling water and an output signal P of the pressure sensor mentioned above. An electric power for the electronic control unit and other components is supplied from an onboard battery...

127Airflow metering

Controlled by the throttle, we need to be able to measure its mass, so that we can meter the appropriate mass of fuel into it. In some applications, the air flow is measured simply by using a sensor detecting throttle angle, which signals volume flow to the electronic control unit (ECU). These signals, in association with others from manifold temperature and pressure sensors, are the basis on which the ECU calculates the mass air flow into the engine. These are termed volume-density computations. An alternative is to use speed-density computations, which are based on signals from engine speed and air temperature and pressure sensors.

Running Distance

The heaters are connected in parallel to an electric power source via lead wires. The electric power source consists of a battery and an alternator of the engine. Also, a common relay is provided on the lines. The relay is set ON and OFF by the signal from an electronic control unit (ECU) in such a manner that ON and OFF of the heaters can be controlled simultaneously. The ECU controls fuel injections and ignition timing of the engine and ON OFF operation of the heaters of the heater-converters.

Robert Bosch GmbH

The method of DE19537788 (1997) is applied for the engine layout of fig. 150 The engine of fig. 150 is a Diesel engine with an a exhaust system comprising an oxidation catalytic converter and or a reduction catalytic converter. A temperature sensor is installed upstream of the converter and fuel (HC) is supplied to the exhaust gases by means of a fuel metering device. The quantity of hydrocarbons supplied is dependent on the operation parameters of the engine and is used for reduction of NOx in the catalytic converter. A HC sensor installed downstream of the converter(s) measures the content of HC in the exhaust gases and an air flow meter measures the quantity of intake air. A rotational speed sensor measures the rotational speed of the engine and a fuel metering device meters the fuel injected to the engine. An electronic control unit receives information from the sensors and adjusts the fuel quantity injected in the engine and the quantity of HC supplied to the exhaust pipe. A...

Common technology

Microcontrollers, in common with other computers, contain a control unit and presumably in order to avoid any possible confusion, the 'black box' that used to be known as the Electronic Control Unit (ECU) is now commonly referred to as the Electronic Control Module (ECM). In this book, the term electronic control module (ECM) is used when referring to the control module that was formerly known as the ECU. equipment are now producing equipment which, when supported by information and data about diagnostic trouble codes (fault codes), provides the knowledgeable technician with the support that should enable him her to go forward in to the 2000s with a degree of confidence in their ability to maintain and repair modern systems.

The Computer ECM

Computer System Transmission

Whilst vehicle computers (ECMs) are not made to be repaired in garage workshops, there are certain factors that require technicians to have an appreciation of computer technology. For example, diagnostic trouble codes (DTCs) are an important part of fault finding and DTCs are stored in the computer memory. The means by which these codes are read out varies from vehicle to vehicle and it is helpful for technicians to understand why a procedure for reading DTCs on one vehicle may not work on another vehicle. It is also the case that technicians in some main dealer workshops are required to use special equipment to amend the computer operating program. Increasingly, use is being made of 'freeze frame' data. This is 'live' data that is captured whilst the system is in operation and it is useful in helping to determine the causes of a system fault. Whilst these operations are normally performed through the use of 'user friendly' diagnostic equipment, it is still the case that an...

Device Net Future

The controller area network (CAN) was developed by Bosch to replace expensive harness wiring. The technology of the CAN bus was devised in the mid-1980s as an in-vehicle network for automobiles. Since the 1980s, the automotive industry has been using electronic control systems for in-vehicle functions and features that improve safety and comfort. Bus systems like CAN overcome some of the limitations of conventional wiring. Using the CAN bus, devices are connected to a common serial bus. Any device on a CAN bus network can communicate with any other device using a common pair of wires. CAN bus features include CAN frames which have identifiers at the beginning of the frames. This identifier is used to identify which When a device transmits a message onto the CAN bus network, all other network devices receive that message. Each receiving device conducts a test on the incoming frame identifier to determine if the message is intended for that device. The CAN bus provides a physical layer...


The evolution of methods concerned with on-board (OBD) and non-OBD monitoring and diagnosing of efficiency of catalytic converters of internal combustion engines is described based on patents and published patent applications. Non-patent references are also used. The catalytic converter has become the most important means of exhaust treatment to achieve the desired emission limits. The international legislation has also created a need for a regular assessment of the efficiency of the catalytic converter in order to detect a deterioration of its conversion efficiency as soon as this deterioration takes place. The assessment of conversion efficiency of a catalytic converter can take place during normal driving of a vehicle (on-board diagnosis or OBD) or in a workshop by specialized technicians. The most important methods nowadays are the OBD methods. This book is an attempt to describe the evolution of methods concerned with on-board (OBD) and non-OBD monitoring and diagnosing of the...


If the sensor reading is not within the required limits it will be read again and if it continues to be 'out of limits' a fault code will be stored in a section of RAM. It is also likely that the designer will have written the main program so that the microcontroller will cause the system to operate on different criteria until a repair can be made, or until the fault has cleared. The fault codes, or diagnostic trouble codes (DTCs), are of great importance to service technicians and the procedures for gaining access to them need to be understood. It should be clear that if they are held in ordinary RAM, they will be erased when the ECM power is removed. This is why various methods of preserving them are deployed.

Do It Yourself Car Diagnosis

Do It Yourself Car Diagnosis

Don't pay hundreds of dollars to find out what is wrong with your car. This book is dedicated to helping the do it yourself home and independent technician understand and use OBD-II technology to diagnose and repair their own vehicles.

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