Temperature Sensor (Gauge): Testing and Inspection

Engine Coolant Temperature (ECT) Sensor -G2-, Checking

If the coolant temperature gauge in the instrument cluster is not working properly, check whether the coolant temperature sensor signal is being received by the instrument cluster.
- Connect scan tool.
- Select "Read Measuring Value Block" function 08.
- Select Display Group 003.

If the coolant temperature is indicated on scan tool, instrument cluster is malfunctioning and must be replaced.
- Removing instrument cluster.

If the coolant temperature is not indicated on scan tool, test the signal at the multi-pin connector on the instrument cluster.
- Removing instrument cluster.
- Connect test box VAG 1598 to the blue 32-pin connector using adapter VAG 1598/25.
- Use multimeter to measure resistance between contacts 8 and 9 (load Ground).

Specifications:
- Coolant temperature 90 degrees C: approx. 110 Ohms
- Coolant temperature 120 degrees C: approx. 50 Ohms

- If measured values do not match specifications, test wiring between instrument cluster and coolant temperature sender using wiring diagram.
- If there are no open circuits or short circuits, replace the coolant temperature sender.