Diagnostic Test
- 1) HIGH SPEED RADIATOR FAN RELAY OPERATION
Ignition on, engine not running.
With a scan tool, actuate the High Speed Radiator Fan Relay.
Is the Cooling Fan Relay operating?
Yes
- Refer to INTERMITTENT CONDITION Diagnostic Procedure.
No
- Go to 2).
- 2) (A16) FUSED B+ CIRCUITS
Turn the ignition off.
Remove the High Speed Radiator Fan Relay.
Using a 12-volt test light connected to ground, probe the (A16) Fused B+ circuits in the Relay connection.
Does the test light illuminate brightly?
Yes
- Go to 3).
No
- Repair the open or short to ground in the (A16) Fused B+ circuits. Inspect the related fuse and repair as necessary.
- Perform BODY VERIFICATION TEST .
- 3) HIGH SPEED RADIATOR FAN RELAY RESISTANCE
Measure the resistance of the High Speed Radiator Fan Relay Coil.
Is the resistance between 60 to 80 ohms?
Yes
- Go to 4).
No
- Replace the Relay.
- Perform POWERTRAIN VERIFICATION TEST .
- 4) (N112) COOLING FAN NO. 2 CONTROL CIRCUIT OPEN
Disconnect the IPM FCM 49 way harness connector.
Measure the resistance of the (N112) Cooling Fan No. 2 Relay Control circuit from the Relay connection to the IPM FCM harness connector.
Is the resistance below 5.0 ohms?
Yes
- Go to 5).
No
- Repair the open in the (N112) Cooling Fan No. 2 Relay Control circuit.
- Perform BODY VERIFICATION TEST .
- 5) (N112) COOLING FAN NO. 2 CONTROL CIRCUIT SHORTED TO GROUND
Measure the resistance between ground and the (N112) Cooling Fan No. 2 Relay Control circuit at the Relay connection.
Is the resistance below 100 ohms?
Yes
- Repair the short to ground in the (N112) Cooling Fan No. 2 Relay Control circuit.
- Perform BODY VERIFICATION TEST .
No
- Go to 6).
- 6) FRONT CONTROL MODULE (FCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Cooling Fan Relay and the Front Control Module (FCM).
Look for any chafed, pierced, pinched, or partially broken wires.
Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Cooling Fan Relay and Front Control Module connectors.
Refer to any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform BODY VERIFICATION TEST .
No
- Replace the Front Control Module per Service Information.
- Perform BODY VERIFICATION TEST .