General Information

Characteristics Of On Board Diagnostic (OBD)

The Engine Control Module (Motronic Engine Control Module (ECM) -J220-) is equipped with DTC memory.

Malfunction recognition
If malfunctions occur at the emission relevant systems or components, they are stored in DTC memory with a description of the malfunction type.

The stored malfunctions can be checked with a standard diagnostic tester See Mode 3: Check DTC memory. Mode 3: Check DTC Memory

The Engine Control Module (ECM) differentiates between different DTCs after evaluating the information, DTC tables.

If the ECM recognizes malfunctions that lead to a worsening of emissions values, it indicates them by lighting the Malfunction Indicator Lamp (MIL) -K83- in the instrument cluster.

Electronic throttle malfunctions are also indicated by the Electronic Power Control (EPC) Warning Lamp -K132- ("EPC warning lamp") in the instrument cluster.

When disconnecting harness connectors from Engine Control Module (ECM) or when disconnecting battery, all adaptation values in the control module are erased. DTC memory content will remain intact however. After re-connecting harness connectors or battery, the following work steps must be performed in the mentioned sequence:

1. Check DTC memory See "Mode 3: Check DTC memory". Mode 3: Check DTC Memory
2. If necessary, erase DTC memory See "Mode 4: Reset/erase diagnostic data". Mode 4: Reset/Erase Diagnostic Data
3. If DTC memory was erased, generate readiness code. Readiness Code, Generating

- End diagnosis and switch ignition off.