Malfunction Indicator Lamp (MIL), Significance

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. Reading Diagnostic Trouble Codes