Thermostat, Checking

Thermostat, Checking

Special tools, testers and auxiliary items required

• Hand-held multimeter (V.A.G 1526 A)

• Connector test set (V.A.G 1594 A)

• Vehicle Diagnostic, Testing and Information System (VAS 5051 A) with diagnostic cable (VAS 5051/5A)

Test Conditions

• Engine cold.

Check internal resistance of heating element

• The Map Controlled Engine Cooling Thermostat (F265) and wire connections are monitored by the Engine Control Module (ECM).

• Vehicle Diagnostic, Testing and Information System (VAS 5051 A) with diagnostic cable (VAS 5051/5A) connected, On-board diagnostic and vehicle system "01 Engine electronics" selected. Thereby, the ignition must be switched on.





- Read out DTC memory of engine control module (ECM).

If a fault related to Map Controlled Engine Cooling Thermostat (F265) is displayed:

- Carefully pull the engine cover at the rear and middle upward and off - arrows 1 -.





- Then, pull the engine cover forward and off from intake manifold - arrows 2 -.

- Separate electrical 2-pin connection - arrow - at Map Controlled Engine Cooling Thermostat (F265).





• To improve clarity, the electrical connector is shown with intake manifold removed.

- Connect multimeter to thermostat for resistance measurement.

• Specified value: 14 to 16 ohms at 25 °C.

If specification is not obtained:

- Replace Map Controlled Engine Cooling Thermostat (F265) => [ Coolant Thermostat ] Service and Repair.

If specified value is achieved:

- Check wire connections according to wiring diagram.