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Home › Jeep › 2007 › Commander Overland, 4WD › Repair and Diagnosis › Engine Performance › System › DTCS P1602 To P2123 › P1647-Hydraulic Cooling Fan Control Circuit High › Diagnostic Test

Diagnostic Test

  1. 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 Diagnostic Procedure.

    No 

    1. Go to  2).
  2. 2) (Z823) GROUND CIRCUIT CHECK 
    Fig 1: Disconnecting Hydraulic Cooling Fan Module Harness Connector
    GC0027201Courtesy of CHRYSLER LLC

    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  3).

    No 

    1. Repair the open in the (Z823) Ground circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .
  3. 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
    GC0027200Courtesy of CHRYSLER LLC

    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  4).

    No 

    1. Go to  5).
    2. Perform POWERTRAIN VERIFICATION TEST .
  4. 4) (K173) HYDRAULIC RADIATOR FAN SOLENOID CONTROL CIRCUIT SHORTED TO VOLTAGE IN THE IPM 
    Fig 3: Checking Hydraulic Radiator Fan Solenoid Control Circuit
    GC0027200Courtesy of CHRYSLER LLC

    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 there any voltage present? 

    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. 5) FRONT CONTROL MODULE (FCM) 

    Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Hydraulic Cooling Fan 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 Hydraulic Cooling Fan and the Front Control Module (FCM) connectors.

    Refer to any Technical Service Bulletins that may apply.

    Were there any problems found? 

    Yes 

    1. Repair as necessary.
    2. Perform BODY VERIFICATION TEST .

    No 

    1. Replace and program the Front Control Module per Service Information.
    2. Perform BODY VERIFICATION TEST .
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