Malfunction Indicator Lamp (MIL), Checking

Special Tools and Equipment







- VAG1594A







- VAG1598/31

Function test of warning lamp
- Switch ignition on.
- Warning lamp for On Board Diagnostic (Malfunction Indicator Lamp -MIL-) must light up

A - Warning lamp for On Board Diagnostic (Malfunction Indicator Lamp -MIL-) does not light up
- Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM. Refer to "Scan Tool Testing/Wire And Component Test Using VAG1598/31 Test Box", Under "Powertrain Management", Testing and Inspection
- Bridge sockets 1 and 47 of test box.
- Switch ignition on.
- Warning lamp must light up.

If warning lamp does not light up:
- Switch ignition off.
- Remove instrument cluster.
- Check the following wire connection for open circuit and short circuit to B+:

Test box VAG1598/31 Socket Instrument cluster Terminal
47

- Repair open circuit or short circuit if necessary.

If wire connection is OK:
- Replace Engine Control Module (ECM).

B - Warning lamp for On Board Diagnostic (Malfunction Indicator Lamp -MIL-) remains lit constantly
- Check DTC memory of Engine Control Module (ECM).

If no DTCs are stored:
- Connect VAG1598/31 test box at wiring harness to ECM, do not connect ECM. Refer to "Scan Tool Testing/Wire And Component Test Using VAG1598/31 Test Box", Under "Powertrain Management", Testing and Inspection
- Remove instrument cluster.
- Check the following wire connection for short circuit to Ground (GND):

Test box VAG1598/31 Socket Instrument cluster Terminal
47 -

- Repair short circuit if necessary.

If wire connection is OK:
- Replace Engine Control Module (ECM).