Checking Engine Coolant Temperature

Checking Engine Coolant Temperature
- Ignition ON.
- o into scrolling values.
- Check that the engine coolant temperature (ECT) sensor reading is within permitted limits.
- Engine coolant temperature should be approx. 80-105°C (176-221°F), at normal operating temperature.

If reading is OK:
^ Proceed to: Connecting the Breakout Box section below.

If reading is incorrect:
^ Proceed to: Checking Engine Coolant Temperature Sensor section below.





Checking Engine Coolant Temperature Sensor
- Ignition ON.
- Go into scrolling values.
- Connect multimeter 999 6525 with temperature box 999 5281 and temperature sensor 999 5282.

WARNING: Danger - coolant is hot.

- Squeeze the hose between the radiator and thermostat housing with a hose clip. Carefully bend it downward and disconnect it from the thermostat housing.
- Insert sensor in thermostat housing and reinstall hose. It is important that the sensor reaches all the way to the thermostat.
- Read OFF temperature on the multimeter.
- GCheck that the Volvo Scan Tool (ST) displays the correct engine coolant temperature.
- Reinstall the hose and expansion tank cap after the check.
- Is the engine coolant temperature correct?

Yes:
^ Check cooling system.

No:
^ Replace engine coolant temperature sensor.





Connecting the Breakout Box
- Connect the breakout box and check ground terminals..
- Connect engine control module (ECM).
- Check all signals to and from engine control module.
- Are all signals OK?

Yes:
^ Proceed to: Checking Catalytic Converter and Exhaust System.

No:
^ Remedy as necessary.