Checking Thermostat

Fig 1: Engine Start Verification

Courtesy of VOLVO CARS CORPORATION

• Start the engine. Run the engine until the engine coolant temperature (ECT) reaches approximately 100 °C
• Activate the engine cooling fan (FC) with the engine running
• Wait for approximately 90 seconds. Then switch off the engine cooling fan (FC).

  Read off the engine coolant temperature (ECT). If the temperature is 85 °C or lower when the fan stops, the thermostat is damaged.

  Fig 2: Identifying VCT2000 Diagnostic Tool Symbol In VIDA

  Courtesy of VOLVO CARS CORPORATION
  Fig 3: Identifying Engine Coolant Temperature Sensor

  Courtesy of VOLVO CARS CORPORATION

Is the temperature lower than 86 °C? 

• YES 

  Refer to REPLACING THE COMPONENT 

• NO 

  FAULT TRACING FAILED:  The fault should have been detected and remedied. As this is not the case fault-tracing has failed. Exit fault-tracing for this diagnostic trouble code (DTC) or make another attempt.