Temperature Gauge: Testing and Inspection

If the engine coolant temperature gauge is inoperative:
- Check for engine coolant temperature signal at instrument cluster as follows.
- Connect VAG 1551 Scan Tool. Testing and Inspection
- Select "Read Measuring Value Block" function 08. Testing and Inspection
- Select channel 003.

- If the engine coolant temperature signal is indicated on the VAG 1551 Scan Tool display, the instrument cluster is faulty and must be replaced.

- If the engine coolant temperature signal is NOT indicated on the VAG 1551 Scan Tool display, the signal must be checked at the multi-pin terminal on the rear of the instrument cluster as follows:
- Remove instrument cluster. [1][2]Procedures
- Connect test box VAG 1598 and adapter cable VAG 1598/4 to yellow 26-pin connector for instrument cluster.
- Using Fluke 83 multimeter, check resistance between terminals 17 and 12 (GND).
- Coolant temperature 90 °C (194 °F): approx. 110 Ohms
- Coolant temperature 120 °C (248 °F): approx. 50 Ohms

If the correct value is NOT achieved:
- Check wiring to engine coolant temperature sensor using applicable wiring diagram.

If wiring is OK:
- Replace engine coolant temperature sensor.