2112 Data Buses For Different Applications

The traction control system described in Chapter 1 operates in 'real-time' and this means that data must move between elements of the system at high speed. Increasing use is being made of the high data speed network system, CAN, for systems such as traction control. CAN originate from Bosch and falls into SAE Class C. It utilizes a two-wire twisted pair for the transmission of data.

The Rover 75 is a modern vehicle that uses several different data buses, as described below.

1. 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).

1. Automatic transmission control unit

2. Engine control module

3. ABS/ traction control ECU

4. Instrument pack

1. Automatic transmission control unit

2. Engine control module

3. ABS/ traction control ECU

4. Instrument pack

Fig. 2.13 The CAN bus system

2. A single-wire bus for doors, lights, sun roof etc. This bus operates at a data speed of 9.6 kbaud (Fig. 2.14).

3. A single-wire bus for diagnostic purposes. This bus operates at 10.4 kbaud (Fig. 2.15).

The twisted pair of the CAN bus system minimizes electrically-initiated interference and virtually eliminates the possibility of messages becoming corrupted.

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.

Get My Free Ebook


Post a comment