Checking Engine Coolant Temperature Sensor

Checking Engine Coolant Temperature
- Start the engine and idle it.
- Go into scrolling values.
- Read off the "ECT" parameter.
- Engine coolant temperature (ECT) should be approx. 80 - 105°C, at normal operating temperature.

If reading is OK:
^ Proceed to Checking the Three-Way Catalytic Converter (TWC) and Exhaust System section.

If reading is incorrect:
^ Proceed to test step below.





Checking Engine Coolant Temperature Sensor
- Ignition on.
- Connect a multimeter 999 6525 with temperature box 999 5281 and temperature sensor 999 5282.
- Carefully remove the expansion tank cover.

WARNING: THE WATER MAY BE EXTREMELY HOT.

- Undo the hose between the rear of the engine and the heater unit.
- Insert engine coolant temperature sensor into the hose.
- Reinstall the hose and expansion tank cover.
- Go into scrolling values.
- Start the engine and idle it.
- Check that the Volvo Scan Tool (ST) displays the correct engine coolant temperature. It may vary a couple of degrees depending on the location of the engine coolant temperature sensor.
- Is the engine coolant temperature correct?

Yes:
^ Carry out a cooling system check.

No:
^ Replace the engine coolant temperature sensor.