April 5, 2026: LEMON Manuals is launched! Read the announcement.

Checking The Component And Wiring

Fig 1: Identifying Ignition OFF

GLL101045

Courtesy of VOLVO CARS CORPORATION

Fig 2: Disconnecting Connector

GLL101071

Courtesy of VOLVO CARS CORPORATION

Ignition off
Disconnect the connector in the heater.
Check the terminals. Check for contact resistance. Check for loose connections. Check for oxidation.

Check the resistance of the engine coolant temperature sensor.

Check the cable between control module terminal #3 and the terminal for the engine coolant temperature (ECT) sensor. Check for a short-circuit to ground.

Check the cable between control module terminal #4 and the terminal for the engine coolant temperature (ECT) sensor. Check for a short-circuit to ground.

Remedy as necessary.

Other information
- see COMPONENT SPECIFICATION
- see SIGNAL SPECIFICATION
- see FUEL FIRED BOOSTER HEATER WATER-IN-FUEL SENSOR
- see CONTENTS
Fig 3: Identifying 14-Pin Connector
Courtesy of VOLVO CARS CORPORATION

Fig 4: Identifying Engine Coolant Temperature (ECT) Sensor
Courtesy of VOLVO CARS CORPORATION

Continue
Refer to VERIFICATION