Malfunction Indicator Lamp: Description and Operation

Malfunction Indicator Lamp, significance

If malfunctions which adversely affect exhaust emissions are recognized by the ECM, they will be communicated to the instrument cluster through the CAN-Bus and indicated by the Malfunction Indicator Lamp (MIL) switching ON.







Location of MIL lamp

1 - MIL lamp
2 - Glow plug indicator light


NOTE: The Glow plug indicator light has a dual function:

- Blinking: A malfunction has been recognized which affects handling. Stored malfunctions can be displayed by either the VAG1551 or VAG1552 Scan Tool.
- The MIL lamp must light up when when the ignition is switched ON: this is a normal function when starting a cold Diesel engine.

The MIL lamp is switched ON when malfunctions are recognized which adversely affect exhaust emissions. If this happens, check DTC memory.