Fault Overview/Troubleshooting (Diagnostic/Test Plan)

Fault overview / Troubleshooting (Diagnostics / Test plan)

Notes on Fault memory / Troubleshooting

Caution: The ABS or ABD warning lamp may in certain cases light up even if no fault is stored in the fault memory. In this case, the following faults may be present:




- Mechanical switch contacts (3 contacts fitted / see arrows) in control unit connector may be bent. This shorts the contacts to ground.

Explanation: Normally those contacts are grounded only when the connector is pulled off. This causes the ABS or ABD warning lamp, respectively, to be activated when the ignition is switched on.

- The "Terminal 61 signal is missing at the control unit when the engine is running. This can be checked on the Actual values menu using System Tester 9288.

- Control unit power supply (PIN 1) below 9.5 Volt (low voltage).

Important notes

After a fault in the anti-lock system has been remedied, the fault memory must be erased. Then run a static test (preliminary electrical system check) using the "Static test" menu. Test drive the car and read out the fault memory once more.

When the hydraulic unit has been replaced or removed and refitted, fill/bleed the system. Then run a system check using the "System check" menu.