General Information

On Board Diagnostic (OBD), Characteristics

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

When malfunctions occur in monitored sensors or components, Diagnostic Trouble Codes (DTCs) are stored in DTC memory with a description of the malfunction type.

The Engine Control Module (ECM) assigns a Diagnostic Trouble Code (DTC) based on it's evaluation of 205 recognized malfunctions see DTC table and stores the DTC until DTC memory is erased. P Code Charts

Malfunctions that occur only intermittently (sporadically) are printed out with the added text "sporadically occurring malfunction". These malfunctions are indicated on the display with the added text "/SP". Sporadic malfunctions are frequently caused by loose contacts or brief open circuits. A sporadic malfunction will be erased if it no longer occurs after 40 warm-up cycles (engine started with coolant temperature below 50 °C - switched off above 72 °C)

Stored DTCs can be identified using the VAG 1551 or VAG 1552 scan tools or the new VAS5051 tester.

If the connector is disconnected from the ECM or the battery is disconnected, all adaptation values in the control module are erased. DTC memory content will remain intact however. If the engine is started after this, a rough, uneven idle can result. In this case, switch ignition on for approx. 60 seconds and then allow engine to run at idle for a few minutes or carry out an extended road test until the adaptation procedure has been completed.
- Read readiness code. If DTC memory was erased or the Engine Control Module (ECM) was disconnected from the continuous B+ supply, the readiness code must be re-generated. Monitors, Trips, Drive Cycles and Readiness Codes. Monitors, Trips, Drive Cycles and Readiness Codes


NOTE: General information regarding On Board Diagnostic (OBD) can be found in the operating instructions for the VAG 1551, VAG 1552 or the new VAS 5051 tester.