Detection of faults

NOTE The fault warning light is connected so that it is on if the connector is not connected to the control unit or if the wire (1) is shorting to earth. Supplied by the instrument panel, it is only off if the battery voltage reaches the wire (1) from the control unit interface.

D1 : protective diode
D2 : LED
R1 & R2 : load resistors

1) Positive from control unit pin 16

Diagnosis of the system with the F/L Tester is only feasible if the peripheral speed of the wheels is below 4 km/h, the battery voltage is over 7 Volts and the A.B.S. system is not operating.
Full diagnosis of the system consists of the following three stages:
1. display of a set of operating parameters;
2. display of any errors that may be present and their deletion;
3. activation of the actuators (active diagnosis).

Detection of faults

This is carried out during performance of basic functions and diagnostic tests relating to the sensors/actuators.

Memorization of the error and structure of the error memory.

The error type code and the error counter are memorized for each error in the order in which they arise. This parameter consists of the code of the last fault which has occurred and the relevant counter. The latter is set at 31 in the event of a fault, and subsequently decreased by 1 for every start-up and subsequent increase in speed to over 20 km/h which takes place without the fault.

Error deletion

The error is deleted as follows:
- by a command from the F/L Tester;
- when the error counter reaches zero.

NOTE As the start-up of the procedure involves disabling the system, the fault warning light remains on throughout the duration of the procedure.
The procedure is interrupted if the vehicle exceeds the speed of 10 km/h.