Pathfinder 2WD V6-4.0L (VQ40DE) (2009)
Auxiliary Water Pump: Testing and Inspection
Diagnosis Procedure
HEATER PUMP
System Description (VQ40DE)
SYSTEM DESCRIPTION
Component Parts
Heater pump control system components are:
-
A/C auto amp.
-
Heater pump relay
-
Heater pump
-
Intake sensor
System Operation
The heater pump improves heater performance specifically at idle conditions. It is designed to operate in either of the following 2 situations:
1. Front blower motor set to maximum speed and temperature control dial (driver or passenger) set to full hot 32°C (90°F) or
2. Engine coolant temperature (signal via CAN communication) minus heater core outlet temperature (intake sensor input to A/C auto amp.) is
greater than 20°C (68°F). If the difference is less than 16°C (61°F), the heater pump will not operate unless the conditions in item No. 1 above are
met.
HEATER PUMP
Diagnosis Procedure (VQ40DE)
DIAGNOSTIC PROCEDURE FOR HEATER PUMP CIRCUIT
1.CHECK POWER SUPPLY TO HEATER PUMP
1. Disconnect heater pump connector.
2. Turn ignition switch ON.
3. Set front blower motor to maximum speed.
4. Turn temperature control dial (passenger or driver) to full hot 32°C (90°F).
5. Check voltage between heater pump harness connector E141 terminal 1 and ground.