[v8volvo]

OK sounds good.

The sensor is a thermistor which works by changing its resistance with different temperature. Low temperature should show high resistance across the two terminals, and then as the sensor warms up the resistance should decrease at a steady rate. Typically the service literature will give a specification for the correct resistance for a cold sensor and at regular engine operating temperature, to allow the sensor to be tested for correct operation.

With the multimeter set to measure resistance (ohms), disconnect the electrical connector from the sensor and then touch the two multimeter probes to the two sensor terminals. One probe goes on each terminal. For measuring resistance it doesn't matter which probe you use in which position, the measurement is the same.

Depending on what type of multimeter you have, you may need to choose the correct range to get a valid reading for the resistance of the sensor.

Take the measurement with the engine cold (sitting overnight) and again after driving when the engine is fully warm and let us know what the resistance readings you measure are.

In the meantime I will try to find a source of information on what the correct values are to compare your readings to. Here in the US we only had the early model diesel cars which came with a different sensor that uses only one wire so US D24 service information doesn't have the info you need. However, the later US gas cars had a 2-wire sensor like the one on your car. I'm trying to confirm whether the late diesel sensor and gas engine sensor are the same part with the same specs. If not, we may need to get a forum member from outside the US to test a known good sensor on a different car.