Diagnostic Test

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

1) LOW 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
1. Refer to INTERMITTENT CONDITION .
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Go To step 2).
2) (N112) COOLING FAN NO.2 RELAY CONTROL CIRCUIT SHORTED TO BATTERY VOLTAGE
Turn the ignition off.

Remove the High Speed Radiator Fan Relay.

Disconnect the IPM FCM 49 way harness connector.

Ignition on, engine not running.

Measure the voltage on the (N112) Cooling Fan No.2 Relay Control Circuit at the Relay terminal.

Is the voltage above 0 volts?

Yes
1. Repair the short to battery voltage in the (N112) Cooling Fan No.2 Relay Control circuit.
2. Perform BODY VERIFICATION TEST - VER 1 .
No
1. Go To step 3).
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
1. Go To step 4).
No
1. Replace the High Speed Radiator Fan Relay.
2. Perform POWERTRAIN VERIFICATION TEST .
4) FRONT CONTROL MODULE
NOTE: Before continuing, check the FCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes
1. Repair as necessary.
2. Perform BODY VERIFICATION TEST - VER 1 .
No
1. Replace Front Control Module per Service Information.
2. Perform BODY VERIFICATION TEST - VER 1 .