Diagnostic trouble code information

Condition 

Fig 1: Identifying Fuel Pump, Water Pump, And Heater Fan Power Supply Diagram

Courtesy of VOLVO CARS OF NORTH AMERICA.

If the power supply from the control unit to the fuel pump, water pump and heater fan is short-circuited to ground or if there is an open circuit, the control unit will interpret this as a fault, and diagnostic trouble code CEM-5F43 will be set.

Substitute Value 

• None.

Possible Source 

• Contact resistance in control unit connector.
• Voltage supply circuit short-circuited to ground.
• Open circuit in power supply wire.

Fault symptom[s] 

• Poor interior heating.