FixVault

Diagnostic Test

  1. ACTIVE Diagnostic Trouble Code (DTC) 
    1. 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 may result in possible serious or fatal injury.
      NOTE: It may be necessary to test drive the vehicle and operate the speed control in order for this DTC to set.
    2. With the scan tool, select View DTCs.

      Is the DTC active at this time?

      Yes 

      • Go to step  2

      No 

  2. SPEED CONTROL SWITCHES 
    1. Turn the ignition off.
    2. Remove and disconnect the Speed Control Switches from the steering wheel in accordance with the Service Information.
    3. Measure the resistance across each Speed Control Switch.
    4. Monitor the ohmmeter while pressing each function button on each switch.
    5. The following resistance specifications are taken between terminals (V37) S/C Switch No. 1 Signal and (V937) S/C Switch Return circuits of the Switch when holding the switch button in the following positions:
    • Not pressing any switch - 20.5k ohms
    • On/Off - 0.47k ohms
    • Set - 5.49k ohms
    • Coast - 2.94k ohms
    • Cancel - 1.24k ohms
    • Resume/Accel - 15.4k ohms
  3. SPEED CONTROL ON/OFF SWITCH 
    1. Connect the Resume/Accel Switch.
    2. Ignition on, engine not running.
    3. With the scan tool, monitor the Speed Control Switch voltage.
    4. Disconnect the Speed Control On/Off Switch harness connector.

      Did the voltage change to greater than 4.8 Volts?

      Yes 

      No 

      • Go to step  4
  4. SPEED CONTROL RESUME/ACCEL SWITCH 
    1. With the scan tool, monitor the Speed Control Switch voltage.
    2. Disconnect the Speed Control Resume/Accel Switch harness connector in accordance with the Service Information.

      Did the voltage change greater than 4.8 volts?

      Yes 

      No 

      • Go to step  5
  5. CLOCKSPRING 
    1. Turn the ignition off.
    2. Disconnect the C1 Clockspring harness connector accordance with Service Information.
    3. Ignition on, engine not running.
    4. With the scan tool, read the S/C Switch voltage.

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

      Yes 

      No 

      • Go to step  6
  6. (V37) S/C SWITCH NO. 1 SIGNAL CIRCUIT SHORTED TO THE (V937) S/C SWITCH RETURN CIRCUIT 
    Fig 1: Measuring Resistance Between S/C Switch Signal Circuit And S/C Switch Return Circuit In Speed Control Harness Connector
    GC0090885Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Connect the Clockspring harness connectors in accordance with the Service Information.
    3. Disconnect the C3 PCM harness connector.
    4. Measure the resistance between the (V937) S/C Switch Return circuit and the (V37) S/C Switch No. 1 signal circuit at the Speed Control Switch.

      Is the resistance less than 5.0 ohms?

      Yes 

      No 

      • Go to step  7
  7. (V37) S/C SWITCH NO. 1 SIGNAL CIRCUIT SHORTED TO GROUND 
    Fig 2: Measuring Resistance Between Ground And S/C Switch Signal Circuit In Speed Control Harness Connector
    GC0090884Courtesy of CHRYSLER LLC
    1. Measure the resistance between ground and the (V37) S/C Switch No. 1 signal circuit in the Switch harness connector.

      Is the resistance less than 100 ohms?

      Yes 

      No 

      • Go to step  8
  8. 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 PCM Pinout Box 8815 and PCM Pinout Box Adapter 8815-1 to perform diagnosis.
    1. Install Miller Special Tool #8815-1 on the C3 PCM harness connector.
    2. Connect the S/C Switch harness connectors.
    3. Connect the Clockspring harness connectors.
    4. Turn the ignition on.
    5. With the scan tool, monitor the S/C Switch voltage readings.
    6. Using a voltmeter check the voltage on the (V37) S/C Switch No. 1 signal circuit and the (V38) S/C Switch No. 2 signal circuit at the appropriate terminals of the special tool #8815.
    7. Monitor the voltmeter.
    8. With the 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 and 1.13 volts 3.53 and 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
    9. 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 0.2 of a Volt difference between the voltmeter switch values and the scan tool switch value?

      Yes 

      No 

      • Go to step  9
  9. POWERTRAIN CONTROL MODULE (PCM) 
    1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Speed Control Switch and the PCM.
    2. Look for any chafed, pierced, pinched, or partially broken wires.
    3. Look for broken, bent, pushed out or corroded terminals. Verify there is good pin to terminal contact in the Switch and PCM connectors.
    4. Refer to any Technical Service Bulletins (TSBs) that may apply.

      Were there any problems found?

      Yes 

      No