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Diagnostic Test

  1. DTC IS ACTIVE 

    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 status Active for this DTC? 

    Yes 

    1. Go to  2.

    No 

    1. Refer to the *CHECKING FOR AN INTERMITTENT DTC Diagnostic Procedure.
  2. LEFT SPEED CONTROL SWITCH 
    Fig 1: Speed Control Switch Harness Connectors - Pins 2 And 3
    GC0049631Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the Left Speed Control Switch harness connector.

    Turn the ignition on.

    With the scan tool, read the (V37) S/C Signal 1 input voltage.

    NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 volt) with the connector disconnected.

    Turn the ignition off.

    Connect a jumper wire between the (V37) S/C Signal 1 and the (K975) S/C Switch Ground circuit in the Left Speed Control Switch harness connector.

    Turn the ignition on.

    With the scan tool, read the (V37) S/C Signal 1 input voltage.

    NOTE: The sensor voltage should be approximately 0.0 volts (plus or minus.1 volt) with the jumper wire in place.

    Is the voltage on the scan tool displayed as described above? 

    Yes 

    1. Replace the Left Speed Control Switch in accordance with the Service Information.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  3.
  3. RIGHT SPEED CONTROL SWITCH 
    Fig 2: Speed Control Switch Harness Connectors - Pins 2 And 3
    GC0049631Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the Right Speed Control Switch harness connector.

    Turn the ignition on.

    With the scan tool, read the (V37) S/C Signal 1 input voltage.

    NOTE: The sensor voltage should be approximately 5.0 volts (plus or minus.1 volt) with the connector disconnected.

    Turn the ignition off.

    Connect a jumper wire between the (V37) S/C Signal 1 and the (K975) S/C Switch Ground circuit in the Right Speed Control Switch harness connector.

    Turn the ignition on.

    With the scan tool, read the (V37) S/C Signal 1 input voltage.

    NOTE: The sensor voltage should be approximately 0.0 volts (plus or minus.1 volt) with the jumper wire in place.

    Is the voltage on the scan tool displayed as described above? 

    Yes 

    1. Replace the Right Speed Control Switch in accordance with the Service Information.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  4.
  4. (V37) S/C SIGNAL 1 CIRCUIT SHORTED TO VOLTAGE 
    Fig 3: Speed Control Switch Harness Connectors - Pin 3
    GC0049632Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Disconnect the Powertrain Control Module (PCM) connector.

    Turn the ignition on.

    Measure the voltage of the (V37) S/C Signal 1 circuit.

    Is there any voltage present? 

    Yes 

    1. Repair the (V37) S/C Signal 1 circuit for a short to voltage.
    2. Perform PCM VERIFICATION TEST .

    No 

    1. Go to  5.
  5. (V37) S/C SIGNAL 1 CIRCUIT SHORTED TO GROUND 
    Fig 4: Measuring Resistance Between Ground And S/C Signal 1 Circuit
    GC0049633Courtesy of CHRYSLER LLC

    Turn the ignition off.

    Measure the resistance between ground and the (V37) S/C Signal 1 circuit.

    Is the resistance above 100 ohms? 

    Yes 

    1. Go to  6.

    No 

    1. Repair the (V37) S/C Signal 1 circuit for a short to ground.
    2. Perform PCM VERIFICATION TEST .
  6. (V37) S/C SIGNAL 1 CIRCUIT SHORTED TO THE (K975) S/C SWITCH GROUND CIRCUIT 
    Fig 5: Measuring Resistance Between S/C Signal 1 Circuit And S/C Switch Ground Circuit
    GC0049634Courtesy of CHRYSLER LLC

    Measure the resistance between the (V37) S/C Signal 1 circuit and the (K975) S/C Switch Ground circuit.

    Is the resistance above 100 ohms? 

    Yes 

    1. Go to  7.

    No 

    1. Repair the (V37) S/C Signal 1 circuit for a short to the (K975) S/C Switch Ground circuit.
    2. Perform PCM VERIFICATION TEST .
  7. (V37) S/C SIGNAL 1 CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 6: Measuring Resistance Of S/C Signal 1 Circuit Between Speed Control Switch Harness Connectors And Appropriate Terminal Of Special Tool #8815
    GC0049635Courtesy 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 (V37) S/C Signal 1 circuit between the Left Speed Control Switch harness connector and the appropriate terminal of special tool #8815 and between the Right Speed Control Switch harness connector and the appropriate terminal of special tool #8815.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Go to  8.

    No 

    1. Repair the (V37) S/C Signal 1 circuit for an open circuit or high resistance.
    2. Perform PCM VERIFICATION TEST .
  8. (K975) S/C SWITCH GROUND CIRCUIT OPEN OR HIGH RESISTANCE 
    Fig 7: Measuring Resistance Of S/C Switch Ground Circuit Between Speed Control Switch Harness Connectors And Appropriate Terminal Of Special Tool #8815
    GC0049636Courtesy 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 (K975) S/C Switch Ground circuit between the Left Speed Control Switch harness connector and the appropriate terminal of special tool #8815 and between the Right Speed Control Switch harness connector and the appropriate terminal of special tool #8815.

    Is the resistance below 5.0 ohms? 

    Yes 

    1. Go to  9.

    No 

    1. Repair the (K975) S/C Switch Ground circuit for an open circuit or high resistance.
    2. Perform PCM VERIFICATION TEST .
  9. POWERTRAIN CONTROL MODULE (PCM) 

    Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Left Speed Control Switch and the Powertrain Control Module (PCM) and the Right Speed Control Switch and the Powertrain Control Module (PCM).

    Look for any chafed, pierced, pinched, or partially broken wires.

    Look for broken, bent, pushed out or corroded terminals.

    Refer to any Technical Service Bulletins that may apply.

    Were any problems found? 

    Yes 

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

    No 

    1. Replace the Powertrain Control Module (PCM) in accordance with the Service Information.
    2. Perform PCM VERIFICATION TEST .
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