Control Module Replacement (Service Funtions - Functional Tests)

Renewing The Control Module

After the DSC control module has been replaced, the following work must be performed in this order.

1. Coding

2. Calibration of the DSC sensors
- Steering angle sensor
- Rotation rate sensor
- Lateral-acceleration sensor

3. End-of-line test (with driving curves and pressure sensor test)
The end-of-line test serves to check the DSC sensors in the plant at the end of the assembly line. This test is active on every factory-new DSC control module and it must therefore also be run every time a factory-new DSC control module is fitted.

Procedure for end-of-line test:

The sequence varies depending on the vehicle model and control-module version. Due to the identification of the DSC control module by the DIS tester, the following procedure results.
- Disconnect the diagnostic plug to exit from the diagnostic mode.
- Bring the vehicle into a position that allows driving forwards in a curve.
- Switch off the ignition for at least 10 seconds to perform a reset of the DSC.
- Start the engine.
- Standstill calibration: After the engine startup, the DSC indicator lamp, the ABS indicator lamp and the general brake warning light come on simultaneously (the end-of-line test is active). After approx. 2 seconds, the DSC indicator lamp goes out.
- Check of the rotation rate and lateral-acceleration sensor: Drive in a curve with a small radius; the ABS indicator lamp goes out.
- Check of the pressure sensor: When the ABS indicator lamp goes out, you must press the brake pedal strongly. The general brake warning light goes out and the end-of-line test has been completed successfully

Faults during end-of-line test:

If the end-of-line test is not concluded successfully (one or more indicator lamps light up), the DSC is not working and at least the fault "6D end-of-line test not carried out" is entered in the fault memory with the status "currently present".
- The DSC indicator lamp does not go out after approx. 2 seconds.
The DSC has not run a reset or there is a fault. Switch off the ignition again for at least 10 seconds. If this does not lead to a reset, the reset can also be forced by briefly disconnecting the fuse of the DSC power supply via terminal 87. If DSC indicator lamp still does not go out after this, the fault must be pinpointed.
- The ABS indicator lamp goes not go out and the DSC indicator lamp lights up again.
The end-of-line test must be repeated. If the end-of-line test fails a second time, it is likely that there is a fault in the area of the rotation rate and lateral-acceleration sensor. Run troubleshooting.
- The general brake warning lamp does not go out.
There is a fault in the area of the pressure sensor. Run troubleshooting.