Auxiliary Coolant Pump Control Circuit Low (MTC)

B107E-AUXILIARY COOLANT PUMP CONTROL CIRCUIT LOW (MTC)





For a complete wiring diagram refer to Diagrams/Electrical.

Theory of Operation

The protected Auxiliary Coolant Pump Driver is set low when turned off and set high when turned on. The Auxiliary Coolant Pump Driver will go low if the driver circuit is shorted to ground.

- When Monitored:

When Auxiliary Coolant Pump operation is requested.

- Set Condition:

If the (C43) Auxiliary Coolant Pump Driver circuit is shorted to ground. This DTC has a maturing time of 10 seconds and a de-maturing time of 10 seconds. If the DTC's status changes from active to stored it will stay in memory for 100 ignition cycles.





NOTE: DTC B107E must be active for the results of this test to be valid. Do not perform this test if DTC B107E is stored. Refer to HVAC System Test (MTC) for stored DTC test procedures. HVAC System Test (MTC)

Diagnostic Test

1.CHECK FOR DTC B107E-AUXILIARY COOLANT PUMP CONTROL CIRCUIT LOW WITH AUXILIARY COOLANT PUMP DISCONNECTED





Set the blend control to the full cold position.

Turn the ignition on.

With the scan tool, erase HVAC DTCs.

Turn the ignition off.

Disconnect the Auxiliary Coolant Pump harness connector.

Turn the ignition on.

With the scan tool, select the following: Actuators, Auxiliary Coolant Pump, Start, and Constant On. Allow the actuator to run for approximately one minute.

With the scan tool, read HVAC DTCs.

Does the scan tool display: B1080-AUXILIARY COOLANT PUMP CONTROL CIRCUIT OPEN?

Yes

- Replace the Auxiliary Coolant Pump.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 2

2.CHECK (C43) AUXILIARY COOLANT PUMP DRIVER CIRCUIT FOR A SHORT TO GROUND





Turn the ignition off.

Disconnect the A/C Heater Control C1 harness connector.

Measure the resistance of the (C43) Auxiliary Coolant Pump Driver circuit between ground and the Auxiliary Coolant Pump harness connector.

Is the resistance below 10K ohms?

Yes

- Repair the (C43) Auxiliary Coolant Pump Driver circuit for a short to ground.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Replace the A/C Heater Control.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test