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) HYDRAULIC COOLING FAN OPERATION
Ignition on, engine not running.

Using the scan tool, perform the Hydraulic Fan Solenoid Test.

Does the Hydraulic Cooling Fan operate properly?

Yes
1. Refer to INTERMITTENT CONDITION .
No
1. Go To step 2).
2) (Z823) GROUND CIRCUIT CHECK

Fig 1: Checking Ground Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the Hydraulic Cooling Fan Module harness connector.

Using a 12-volt test light connected to B+, probe the (Z823) Ground circuit in the Hydraulic Cooling Fan Module harness connector.

Does the test light illuminate brightly?

Yes
1. Go To step 3).
No
1. Repair the open in the (Z823) Ground circuit.
2. Perform POWERTRAIN VERIFICATION TEST .
3) (K173) HYDRAULIC RADIATOR FAN SOLENOID CONTROL CIRCUIT SHORTED TO VOLTAGE BETWEEN THE FAN AND IPM FCM 49 WAY HARNESS CONNECTOR

Fig 2: Checking Hydraulic Radiator Fan Solenoid Control Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Disconnect the IPM FCM 49 way connector.

Ignition on, engine not running.

Measure the voltage on the (K173) Hydraulic Radiator Fan Solenoid control circuit at the Hydraulic Fan Module harness connector.

Is the voltage above 0 volts?

Yes
1. Go To step 4).
No
1. Go To step 5).
2. Perform POWERTRAIN VERIFICATION TEST .
4) (K173) HYDRAULIC RADIATOR FAN SOLENOID CONTROL CIRCUIT SHORTED TO VOLTAGE IN THE IPM

Fig 3: Checking Hydraulic Radiator Fan Solenoid Control Circuit
Courtesy of DAIMLERCHRYSLER CORP.

Turn the ignition off.

Disconnect the C2 IPM 40 way harness connector.

Ignition on, engine not running.

Measure the voltage on the (K173) Hydraulic Radiator Fan Solenoid control circuit at the Hydraulic Fan Module harness connector.

Is the voltage above 0 volts?

Yes
1. Repair the short to voltage in the (K173) Hydraulic Radiator Fan Solenoid control circuit between the Hydraulic Cooling Fan Module harness connector and the C2 IPM harness connector.
2. Perform POWERTRAIN VERIFICATION TEST .
No
1. Replace the Integrated Power Module per Service Information.
2. Perform POWERTRAIN VERIFICATION TEST .
5) 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 and program the Front Control Module per Service Information.
2. Perform BODY VERIFICATION TEST - VER 1 .