Self-diagnostics when switching on the ignition
The ABS-ECU performs a self-diagnosis after the ignition is switched on. At the same time, the ABS warning indicator lights up for 3 seconds. In the event of a malfunction, the indicator does not turn off. Also, in the event of a malfunction and subsequent successful repair, the indicator will light up when the ignition is turned on for the first time after the repair until the vehicle reaches a speed of 10 km / h (it means confirmation of the solution of the problem).
Self-diagnosis when turning on the ABS system
When the vehicle speed reaches 10 km/h, the ABS-ECU performs the following tests:
- checking the operation of the electric pump and solenoid valves (only when the ABS is activated for the first time within one ignition);
- Checking wheel speed sensors.
Permanent self-diagnosis
The ABS-ECU constantly checks the following:
- power supply to the ECU; checks voltage;
- wheel speed sensors; checks the signals of the sensors - whether they are present while driving and whether they exceed the possible value at a given vehicle speed;
- electric pump and solenoid valves; checks the outgoing signals and the operating state - whether they correspond to each other.
Safe mode feature
If a malfunction is detected during self-diagnosis, ABS and brake system warning indicators turn on (in case in EBD), and ABS and EBD are controlled as shown in the table.
* - only in cars with all-wheel drive.