Troubleshooting program The following troubleshooting program contains all faults which can be detected by the diagnostic system. The order corresponds to the numerical sequence of the flash code, irrespective of the significance of the fault. It is therefore not arranged on the basis of “fault is indicated by EDC indicator lamp” or “fault is not indi- cated by EDC indicator lamp”. The entire fault code memory should always be read out and all stored fault codes noted down before start- ing the engine test. This is important because lines or components need to be disconnected when troubleshooting the system and this can cause the corresponding fault codes to be set and stored.
For this reason, the fault memory should always be cleared after intermediate checks. The “test lines” test stage must always be performed as follows: Break or contact resistance Set-point: approx. 0 Ω Short to negative Set-point value: Short to positive Set-point value: Short to adjacent lines Set-point value: Loose contacts After rectifying faults and checking, repeat test and delete fault code memory. All checks which refer to the control unit plug connector are conducted with the aid of the socket box. The pin designations on the control unit plug connector are identical to those of the test sockets on the socket box. Note:
The connection to the control unit must be disconnected at the socket box when resistance measurements are being carried out. 29