Fault Tracing Procedure

SELF-TEST AND FAULT INDICATION
The ABS system control unit detects faults in the system, stores DTCs and indicates where the fault lies on demand by emitting flashing fault codes via the DLC. DTCs are stored until erased, even after faults have disappeared or been dealt with, although they are erased automatically once the car has been started 50 times since the fault occurred or was dealt with. There are two types of faults, continuous and intermittent faults. During a continuous fault, the fault code is stored and the warning tight flashes. During an intermittent fault, the fault code is stored and the light is unlit.

WARNING DRIVER OF FAULTS
The system warns the driver that there is a fault by turning on the ABS warning light on the dashboard. A warning is given each time a fault is discovered while driving; if the fault persists, one is also given each time the ignition is switched on and the engine starts.





FAULT INDICATION (SERVICE PERSONNEL)
^ The DLC in the engine compartment can be used to read out and erase faults. For details of the DLC.
^ If fault symptoms only occur intermittently, the DTCs may provide some guidance.
^ There are two modes, one for reading off DTCs and the other for changing the transmission speed:
- DTM 1 for reading off DTCs.
- All DTCs have a DTC table.
- DTM 4 for changing the speed at which the D1 transmits DTCs.

OTHER SYMPTOMS
Some faults may occur without any information being available via a DTC or table directly. In these cases, fault-tracing involves working through to the fault by using secondary DTCs and eliminating possible causes in turn. If symptoms only occur intermittently, the DTCs held in memory may give some guidance. For faults or symptoms not included in DTCs.
^ Faults which do not generate DTCs. Carry out basic checks.
^ Carry out fault-tracing in the order shown below.

FAULT-TRACING
Before starting fault-tracing, check:
- Condition of battery
- Charging system, generator
- Lead connections
- Other auxiliary systems
All test signals around the 12 volt level vary with the battery voltage; figures should therefore be used as guidelines only.

NOTE: Always switch ignition off before connecting or disconnecting the control unit, test equipment and/or connectors.