Malfunction Indicator Lamp (MIL) In Cluster, Check

Malfunction Indicator Lamp (MIL) In Instrument Cluster, Checking

Meaning of emissions MIL
The Malfunction Indicator Lamp (MIL) lights up when emissions relevant malfunctions are recognized by the Engine Control Module (ECM).







Component location of emissions MIL

NOTE:
The Malfunction Indicator Lamp (MIL) can blink or remain lit continuously. DTC memory must be checked in each case, Diagnostic mode 3: Check DTC memory. Diagnostic Mode 3: Check DTC Memory
- Blinking: There is a malfunction that causes damage to the catalytic converter in this driving condition. In this case, vehicle must only be driven at reduced performance.
- Continuously lit: There is a malfunction that causes increased emissions. Check DTC memory for Motronic control module.
- DTC memory must still be checked if there are driveability problems or customer complaints and the MIL is not lit, since malfunctions can be stored without causing the MIL to light immediately.

Recommended special tools and equipment
- VAG1526 multimeter or VAG1715 multimeter
- VAG1594 connector test kit
- Wiring diagram

Test requirement







- The respective fuses of instrument cluster must be OK:

Test sequence
- Switch on ignition: The emissions MIL must light up.

If emissions MIL does not light up when ignition is switched on:
- Switch ignition off.
- Check wire from ECM to emissions MIL as follows:
- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test

Vehicles with engine code AEG
- Bridge sockets 2+17 of test box with the respective adapter cables.

Vehicles with engine code AVH, AZG and BDC
- Bridge sockets 2+47 of test box with the respective adapter cables.

Continuation for all vehicles
- Switch on ignition: Emissions MIL must light up.

If Malfunction Indicator Lamp (MIL) does not light up:
- Switch ignition off.
- Remove instrument cluster:
- Check wire connection from Engine Control Module (ECM) to Malfunction Indicator Lamp (MIL) -K83- according to wiring diagram:
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If no malfunctions are detected in wire from Engine Control Module (ECM) to Malfunction Indicator Lamp (MIL):
- Replace Motronic Engine Control Module (ECM) -J220-.

If emissions MIL lights up when ignition is switched on:
- Start engine and let run at idle: Emissions MIL must go out after a few seconds.

If Malfunction Indicator Lamp (MIL) does not go out:
- Switch ignition off.
- Remove instrument cluster:

- Connect test box to control module wiring harness, connect test box for wiring test. Test Box, Connecting For Wiring Test

Vehicles with engine code AEG
- Check wire connection between test box socket 17 and instrument cluster for short circuit to Ground (GND) according to wiring diagram.

Vehicles with engine code AVH, AZG and BDC
- Check wire connection between test box socket 47 and instrument cluster for short circuit to Ground (GND) according to wiring diagram:

Continuation for all vehicles
- Erase DTC memory of Engine Control Module (ECM), Diagnostic mode 4: Reset/erase diagnostic data. Diagnostic Mode 4: Reset/Erase Diagnostic Data
- Generate readiness code. Monitors, Trips, Drive Cycles and Readiness Codes

If no malfunctions are detected in wire from Engine Control Module (ECM) to Malfunction Indicator Lamp (MIL):
- Replace Motronic Engine Control Module (ECM) -J220-.