Work sequence

WARNING: This page is about a different car, the 2006 Volkswagen Golf, 2005 Volkswagen Jetta, 2005 Volkswagen Golf, 2004 Volkswagen Jetta, and 2004 Volkswagen Golf. However, it is still accessible from the selected car via links, so may be relevant.

Disconnect connector on Engine Coolant Temperature (ECT) sensor -G62-.

NOTE:

Disconnecting the sensor simulates the engine condition "cold" and when switching the ignition on the relevant glow period is initiated.

Disconnect glow plug connector.
Connect multimeter to measure voltage between a glow plug connector and vehicle ground.
Switch on ignition for approx. 20 seconds. Approx. battery voltage must be displayed.
If no voltage is present: Electrical Wiring Diagrams, Troubleshooting Component Locations.