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Home >> Jeep >> 2007 >> Commander Base, 4.7 P, AWD >> Repair and Diagnosis (Single Page) >> Engine Performance >> System >> DTCS P0503 To P0580 >> P0580-Speed Control Switch 1 Circuit Low >> 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 

    Turn the ignition off.

    Remove and disconnect the Speed Control Switches from the steering wheel per Service Information.

    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 (V371) S/C Switch No. 1 Signal and (V397) S/C Switch Return circuits of the Switch when holding the switch button in the following positions.

    Not pressing any switch - 20.5 kohms

    On/Off - 0.47 kohms

    Set - 5.49 kohms

    Coast - 2.94 kohms

    Cancel - 1.24 kohms

    Resume/Accel - 15.4 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) SPEED CONTROL ON/OFF SWITCH 

    Connect the Resume/Accel Switch.

    Ignition on, engine not running.

    With the scan tool, monitor the Speed Control Switch voltage.

    Disconnect the Speed Control On/Off Switch harness connector.

    Did the voltage change to above 4.8 volts? 

    Yes 

    1. Replace the Speed Control On/Off Switch.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  4).
  4. 4) SPEED CONTROL RESUME/ACCEL SWITCH 

    With the scan tool, monitor the Speed Control Switch voltage.

    Disconnect the Speed Control Resume/Accel Switch harness connector per Service Information.

    Did the voltage change to above 4.8 volts? 

    Yes 

    1. Replace the Speed Control Resume/Accel Switch.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  5).
  5. 5) STEERING COLUMN CONTROL MODULE 

    Turn the ignition off.

    Disconnect the C1 SCCM harness connector per Service Information.

    Ignition on, engine not running.

    With the scan tool, read the S/C Switch voltage.

    Did the S/C Switch volts change to 5.0 volts? 

    Yes 

    1. Replace the Clockspring.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  6).
  6. 6) (V371) S/C SWITCH NO. 1 SIGNAL CIRCUIT SHORTED TO THE (V397) S/C SWITCH RETURN CIRCUIT 
    Fig 1: Checking Speed Control Switch No. 1 Signal Circuit Shorted To Return Circuit
    GC0027159Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the C3 SCCM harness connector.

    Disconnect the C3 PCM harness connector.

    Measure the resistance between the (V397) S/C Switch Return circuit and the (V371) S/C Switch No. 1 Signal circuit at the S/C Switch harness connectors.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Repair the short between the (V371) S/C Switch No. 1 Signal circuit and the (V397) S/C Switch Return circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  7).
  7. 7) (V71) S/C SWITCH NO. 1 SIGNAL CIRCUIT SHORTED TO THE (V937) S/C SWITCH RETURN CIRCUIT 
    Fig 2: Checking Speed Control Switch No. 1 Signal Circuit & Return Circuit
    GC0027160Courtesy of CHRYSLER LLC

    Measure the resistance between the (V71) S/C Switch No. 1 Signal circuit and the (V937) S/C Switch Return circuit in the C1 SCCM harness connector.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Repair the short between the (V71) S/C Switch No. 1 Signal circuit and the (V937) Switch Return circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  8).
  8. 8) (V371) S/C SWITCH NO. 1 SIGNAL CIRCUIT SHORTED TO GROUND 
    Fig 3: Checking Speed Control Switch No. 1 Signal Circuit Shorted To Ground
    GC0027157Courtesy of CHRYSLER LLC

    Measure the resistance between ground and the (V371) S/C Switch No. 1 Signal circuit in the S/C Switch harness connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the short to ground in the (V371) S/C Switch No. 1 Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  9).
  9. 9) (V71) S/C NO. 1 SWITCH SIGNAL CIRCUIT SHORTED TO GROUND 
    Fig 4: Checking Speed Control Switch No. 1 Signal Circuit
    GC0027158Courtesy of CHRYSLER LLC

    Measure the resistance between ground and the (V71) S/C Switch No. 1 Signal circuit in the C1 SCCM harness connector.

    Is the resistance below 100 ohms? 

    Yes 

    1. Repair the short to ground in the (V71) S/C Switch No. 1 Signal circuit.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  10).
  10. 10) SPEED CONTROL SWITCH VOLTAGE VALUES 
    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 and #8815-1 to perform diagnosis.

    Using a voltmeter check the voltage on the (V37) S/C Switch No. 1 Signal circuit at the appropriate terminal of the special tool #8815.

    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.

    Start the engine and allow it to reach normal operating temperature.

    Monitor the voltmeter.

    Allow the engine to idle.

    With a scan tool, monitor the S/C Switch voltage readings.

    SWITCH POSITION  SWITCH No. 1 VOLTAGE VALUE  SWITCH No. 2 VOLTAGE VALUE 
    NO SWITCHES PRESSED 4.31 to 4.78 volts 4.31 to 4.78 volts
    ON/OFF PRESSED 0.59 to 1.13 volts 3.53 to 3.92 volts
    RES/ACCEL PRESSED 3.88 to 4.17 volts 2.04 to 2.47 volts
    SET PRESSED 3.16 to 3.56 volts 1.17 to 1.56 volts
    COAST PRESSED 2.57 to 2.94 volts 0.77 to 1.09 volts
    CANCEL PRESSED 1.59 to 1.99 volts 2.84 to 3.25 volts

    Compare the voltage readings on the voltmeter to what the scan tool displayed.

    Are the voltage readings out of the listed specification and is there less than a 0.2 of a volt difference between the voltmeter switch values and the scan tool switch value? 

    Yes 

    1. Replace the Speed Control Switch.
    2. Perform POWERTRAIN VERIFICATION TEST .

    No 

    1. Go to  11).
  11. 11) 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 .
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