FixVault

Diagnostic Test

  1. ACTIVE DIAGNOSTIC TROUBLE CODE (DTC) 
    1. Start the engine and allow it to reach operating temperature.
      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.

    2. Increase engine speed by pressing the accelerator pedal. Do not exceed 3500 RPM.
    3. Using the scan tool, read the active DTCs.

      Is the DTC Active at this time?

      Yes 

      • Go To  2.

      No 

  2. GENERATOR OPERATION 
    Fig 1: Checking Generator Field Control Circuit
    GC0138781Courtesy of CHRYSLER GROUP, LLC
    1. Turn the ignition off.
    2. Disconnect the Generator harness connector.
    3. Using a 12-Volt test light connected to ground, probe the (K20) Generator Field Control circuit in the Generator Field harness connector.
    4. Ignition on, engine not running.
      NOTE:

      The DTC needs to be cleared before actuating the Solenoid, if the DTC is not cleared, the Solenoid may not be allowed to actuate.

    5. With the scan tool, actuate the Generator Field Driver.
      NOTE:

      The test light should be illuminated and bright proportional to the maximum duty cycle allowed by the scan tool. For example, if the scan tool allows 100% actuation, the brightness should be as bright as a direct connection to the battery. If the scan tool allows a maximum 25% actuation, the brightness should be 25% as bright as a direct connection to the battery.

      Does the test light illuminate brightly and flash on and off?

      Yes 

      No 

      • Go To  3.
  3. (K20) GEN FIELD CIRCUIT SHORTED TO VOLTAGE 
    Fig 2: Measuring Voltage On Generator Field Control Circuit
    GC0138784Courtesy of CHRYSLER GROUP, LLC
    1. Turn the ignition off.
    2. Disconnect the PCM 2 harness connector.
    3. Ignition on, engine not running.
    4. Measure the voltage on the (K20) Gen Field Control circuit in the Generator Field harness connector.

      Is there any voltage present?

      Yes 

      No 

      • Go To  4.
  4. (K20) GEN FIELD CIRCUIT OPEN 
    Fig 3: Checking Generator Field Circuit For An Open Or High Resistance
    GC0149675Courtesy of CHRYSLER GROUP, LLC
    1. Turn the ignition off.
    2. Measure the resistance of the (K20) Gen Field Control circuit between the Generator harness connector and the PCM C2 harness connector.

      Is the resistance below 5.0 Ohms?

      Yes 

      • Go To  5.

      No 

  5. (K20) GEN FIELD CIRCUIT SHORTED TO GROUND 
    Fig 4: Checking Generator Field Control Circuit For Short To Ground
    GC0138783Courtesy of CHRYSLER GROUP, LLC
    1. Measure the resistance between ground and the (K20) Gen Field Control circuit in the Generator Field harness connector.

      Is the resistance below 1000 Ohms?

      Yes 

      No 

      • Go To  6.
  6. POWERTRAIN CONTROL MODULE (PCM) 
    1. Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Generator and the Powertrain Control Module (PCM).
    2. Look for any chafed, pierced, pinched or partially broken wires.
    3. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the Generator and Powertrain Control Module connectors.
    4. Perform any Technical Service Bulletins that may apply.

      Were there any problems found?

      Yes 

      No