Glow Plug System: Testing and Inspection

Special tools, workshop equipment, testers, measuring instruments and auxiliary items required
- Fluke 83 multimeter
- VW 1594 Adaptor kit







Test Requirements:

- Battery voltage 11.5 Volts minimum
- Switch ON ignition.
- Diesel injection system Engine Control Module J248 OK
- S 189 and S125 strip fuses for glow plug OK

Test Process

- Disconnect Engine Coolant Temperature sensor harness connector-1-.







NOTE: Disconnecting the ECT sensor harness connector simulates a "cold" engine condition and switching ON the ignition starts the pre glow process.


- Disconnect glow plug harness connector from glow plug
- Connect multimeter to measure Voltage between glow plug harness connector and vehicle Ground.
- Switch ON ignition for approx. 20 seconds
- Battery Voltage (approx.) must be displayed
- If NO voltage present
See Wiring Diagrams, Electrical Troubleshooting and Component Locations.