Antilock Brake System
1. The diagnostic socket (green) is located below the righthand front seat.2. During fault diagnosis, the ignition switch must always be in the On position.
3. The ISAT system number for the TC/ABS system is number 3.
4. Always read off and note down all stored fault codes before disconnecting the battery or ECU.
5. If communication cannot be established between ISAT and the ECU, check the leads between ECU pins 23 and 42 and the diagnostic socket. Also check that the power feed and ground circuits to the diagnostic socket are good and the connector pins are not damaged.
6. Once fault codes stored in the systems's ECU have been transferred to ISAT, the diagnosis function is finished. The technician should next enter any command codes which apply to the problem which exists. It is sometimes quite helpful to enter All command codes to check the status of certain signals and components before proceeding with the detailed diagnostic procedure.
7. To avoid doing damage to the ECU, ensure the ignition is off before unplugging the connector.
8. Before tracing faults on a vehicle's electronic systems, always start by checking that the grounding circuits for the ECU concerned are good and that all nominal voltage levels are correct.
9. Unplug connectors and plugs to check the pins are undamaged and not loose. After checking, plug in all connectors and clear all fault codes. Start engine or drive car again to check that the fault or faults persist.
10. When first detected, a fault will be assigned a permanent fault code. If the fault later disappears, the fault will be classified as intermittent.
11. All signals around the 12 volt level are proportional to battery voltage. These levels must therefore be taken only as a rough guide.
12. Zero voltage signal levels indicate ground, although a sensitive multimeter may indicate a value slightly above zero volts.
13. When ISAT command codes are being used to test the system while the car is being driven, communication between ISAT and the ECU will be broken if the speed of the car exceeds 12 mph.
14. If no fault codes can be read from the system even though the warning lights are On, start by checking the safety circuit (pin 8 and 51).
15. Never use the breakout box when car is being driven.