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Home >> Jeep >> 2007 >> Commander Base, 4.7 P, AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> DTCS P0581 To P0643 >> P0593-Speed Control Switch 2 Circuit High >> Diagnostic Test

Diagnostic Test

  1. 1) ACTIVE DTC 

    Start the engine and allow it to idle for at least 60 seconds.

    WARNING: When the engine is operating, do not stand in direct line with the fan. Do not put your hands near the pulleys, belts, or fan. Do not wear loose clothing. Failure to follow these instructions can result in personal injury or death.
    NOTE: It may be necessary to test drive the vehicle and operate the speed control in order for this DTC to set.

    With a scan tool, select View DTCs.

    Is the DTC Active at this time? 

    Yes 

    1. Go to  2).

    No 

    1. Refer to INTERMITTENT CONDITION Diagnostic Procedure.
  2. 2) SPEED CONTROL SWITCHES 

    Disconnect and remove the Speed Control Switches from the steering wheel.

    Measure the resistance across each Speed Control Switch.

    Monitor the ohmmeter while pressing each function button on each switch.

    The following resistance specs are taken between terminals (V372) S/C Switch No. 2 Signal and (V397) S/C Switch Return circuits of the Switch when holding the switch button in the following position.

    Not pressing any switch - 20.5 kohms

    On/Off - 8.87 kohms

    Set - 0.825 kohms

    Coast - 0.47 kohms

    Cancel - 3.92 kohms

    Resume/Accel - 1.87 kohms

    Does the function on the Speed Control Switches have the correct resistance value? 

    Yes 

    1. Go to  3).

    No 

    1. Replace the Speed Control Switch that had the incorrect resistance value.
    2. Perform POWERTRAIN VERIFICATION TEST .
  3. 3) STEERING COLUMN CONTROL MODULE 

    Disconnect the C1 and C3 Steering Column Control Module harness connectors per Service Information.

    Measure the resistance of the (V397) Switch Return circuit between the C1 and C3 SCCM connections.

    Measure the resistance of the (V372) S/C Switch No. 2 Signal circuit between the C1 and C3 SCCM connections.

    Was the resistance above 5.0 ohms for either circuit? 

    Yes 

    1. Replace the Steering Column Control Module per Service Information.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  4).
  4. 4) (V372) SIGNAL NO. 2 CIRCUIT SHORTED TO BATTERY VOLTAGE 
    Fig 1: Checking Speed Control Switch No. 2 Signal Circuit For Short To Voltage
    GC0027169Courtesy of CHRYSLER LLC

    Measure the voltage on the (V372) S/C Signal No. 2 circuit in the S/C Switch harness connector.

    Ignition on, engine not running.

    Is the voltage above 0 volts? 

    Yes 

    1. Repair the short to battery voltage in the (V372) S/C Signal No. 2 circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  5).
  5. 5) (V72) S/C SWITCH NO. 2 SIGNAL CIRCUIT SHORTED TO BATTERY VOLTAGE 
    Fig 2: Checking Speed Control Switch No. 2 Signal Circuit For Short To Voltage
    GC0027175Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the C3 PCM harness connector.

    Ignition on, engine not running.

    Measure the voltage on the (V72) S/C Switch No. 2 Signal circuit in the C1 SCCM harness connector.

    Is the voltage above 0 volts? 

    Yes 

    1. Repair the short to battery voltage in the (V72) S/C Switch No. 2 Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  6).
  6. 6) (V372) S/C SWITCH NO. 2 SIGNAL CIRCUIT OPEN 
    Fig 3: Checking Speed Control Switch No. 2 Signal Circuit For Open
    GC0027173Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Measure the resistance of the (V372) S/C Switch No. 2 Signal circuit from the both Switch harness connectors to the C3 SCCM harness connector.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Go to  7).

    No 

    1. Repair the open in the (V372) S/C Switch No. 2 Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .
  7. 7) (V72) S/C SWITCH NO. 2 SIGNAL CIRCUIT OPEN 
    Fig 4: Checking Speed Control Switch No. 2 Signal Circuit For Open
    GC0027174Courtesy of CHRYSLER LLC
    CAUTION: Do not probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal to pin connection. Install Miller Special Tool #8815 to perform diagnosis.

    Measure the resistance of the (V72) S/C Switch No. 2 Signal circuit from the C1 SCCM harness connector to the appropriate terminal of special tool #8815.

    Is the resistance below 5.0 ohms for both measurements? 

    Yes 

    1. Go to  8).

    No 

    1. Repair the open in the (V72) S/C Switch No. 2 Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .
  8. 8) (V397) SWITCH RETURN CIRCUIT OPEN 
    Fig 5: Checking Speed Control Switch Return Circuit (V397) For Open
    GC0027155Courtesy of CHRYSLER LLC

    Measure the resistance of the (V397) Switch Return circuit from the both Switch harness connectors to the C3 SCCM harness connector.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Go to  9).

    No 

    1. Repair the open in the (V397) Switch Return circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .
  9. 9) (V937) SWITCH RETURN CIRCUIT OPEN 
    Fig 6: Checking Speed Control Switch Return Circuit (V937) For Open
    GC0027156Courtesy of CHRYSLER LLC

    Measure the resistance of the (V937) Switch Return circuit from the C1 SCCM harness connector to the appropriate terminal of special tool #8815.

    Is the resistance below 5.0 ohms for both measurements? 

    Yes 

    1. Go to  10).

    No 

    1. Repair the open in the (V937) Switch Return circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .
  10. 10) PCM 
    NOTE: Before continuing, check the PCM 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 POWERTRAIN VERIFICATION TEST .

    No 

    1. Replace and program the Powertrain Control Module per Service Information.
    2. Perform POWERTRAIN VERIFICATION TEST .