Checking Component And Cables

Check engine coolant temperature sensor resistance. For resistance values, see Component Resistance Values .

Check cable between control module #4 and engine coolant temperature sensor ground terminal for an open-circuit according to Open-Circuit, Permanent Faults .

HINT: Because it is difficult to separate the cables to the engine coolant temperature sensor, measure between control module #4 and both cables to the water temperature sensor. 

Check cable between control module #16 and engine coolant temperature sensor signal terminal for an open-circuit Open-Circuit, Permanent Faults and a short-circuit to supply voltage according to Short-Circuit To Supply Voltage. Permanent Faults .

HINT: Because it is difficult to separate the cables to the engine coolant temperature sensor test the cables one at a time and see if a relevant value was obtained from either of them. 

Remedy as necessary.

Other information: 

• To access the control module/connect breakout box, see Connecting the Breakout Box .
• To access/replace the Coolant temperature sensor, see Replacing Overheat Protection, Thermostat Flame Sensor And Coolant Temperature Sensor .
• With ignition on and the engine coolant temperature sensor signal cable cut the voltage between the engine coolant temperature sensor signal cable (engine control module (ECM) side) and ground should be approximately 5 V.
• For other values, see Signal Specification Additional heater 912-D/B .

Fig 1: Identifying Data Link Connector

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 2: Identifying Ohmmeter

Courtesy of VOLVO CARS OF NORTH AMERICA.

Fig 3: Identifying Coolant Temperature Sensor Circuit

Courtesy of VOLVO CARS OF NORTH AMERICA.

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  Refer to Verification