FixVault

Diagnostic Test

  1. DTC IS ACTIVE 
    NOTE: Inspect the vehicle for aftermarket accessories that may exceed the Generator system output.
    NOTE: Inspect the Generator harness connector and the Generator eyelet for corrosion or damage before continuing.
    NOTE: Inspect the condition and tension of the Generator belt before continuing.
    NOTE: Inspect the battery before continuing.
    1. Ignition on, engine not running.
    2. With a scan tool, select View DTCs. Record DTC and Freeze Frame information
    3. With a scan tool, clear DTCs.
    4. Start the engine and allow it to reach operating temperature.
    5. With the scan tool, select View DTCs.

      Is the status Active for this DTC?

      Yes 

      • Go to step  2

      No 

  2. EXCESSIVE RESISTANCE IN THE B(+) CIRCUIT 
    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: Make sure all test equipment and cables are clear of any belts, pulleys, or other moving parts.
    1. Monitor the voltage between the generator B(+) output terminal and the battery positive (+) post.
    2. Start the engine.

      Is the voltage above 0.4 volts?

      Yes 

      No 

      • Go to step  3
  3. EXCESSIVE RESISTANCE BETWEEN THE GENERATOR CASE AND GROUND 
    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: Make sure all test equipment and cables are clear of any belts, pulleys, or other moving parts.
    1. Monitor the voltage between the generator case and battery ground (-) post.
    2. Start the engine and allow it to reach operating temperature.

      Is the voltage above 0.1 volts?

      Yes 

      No 

      • Go to step  4
  4. (A804) GEN SENSE CIRCUIT SHORTED TO VOLTAGE 
    Fig 1: Checking GEN Sense Circuit
    GC0099990Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the Generator harness connector.
    3. Disconnect the Powertrain Control Module (PCM) harness connector.
    4. Turn the ignition on.
    5. Measure the voltage of the (A804) Gen Sense circuit.

      Is there any voltage present?

      Yes 

      No 

      • Go to step  5
  5. (K20) GEN FIELD CONTROL CIRCUIT SHORTED TO VOLTAGE 
    Fig 2: Checking Generator Field Control Circuit
    GC0099983Courtesy of CHRYSLER LLC
    1. Turn the ignition off.
    2. Disconnect the Generator harness connector.
    3. Disconnect the Powertrain Control Module (PCM) harness connector.
    4. Turn the ignition on.
    5. Measure the voltage of the (K20) Gen Field Control circuit.

      Is there any voltage present?

      Yes 

      No 

      • Go to step  6
  6. GENERATOR FIELD CONTROL ACTUATION 
    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.
    1. Turn the ignition off.
    2. Connect the Generator harness connector.
    3. Connect the Powertrain Control Module (PCM) harness connector.
      NOTE: Make sure all test equipment and cables are clear of any belts, pulleys, or other moving parts.
    4. Measure the voltage between the Generator Eyelet terminal and the (A804) Gen Sense circuit in the Generator harness connector.
    5. Start the engine and allow it to reach operating temperature.

      Is the voltage above 0.1 volts?

      Yes 

      • Go to step  7

      No 

      • Go to step  8
  7. GENERATOR 
    1. Turn the ignition off.
    2. Inspect the wiring and connectors between the Generator and the Powertrain Control Module (PCM).
    3. Look for any chafed, pierced, pinched, or partially broken wires.
    4. Look for broken, bent, pushed out or corroded terminals. Verify that there is good pin to terminal contact in the related connectors.

      Were any problems found?

      Yes 

      No 

  8. 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.
    4. Monitor the scan tool data relative to this circuit and wiggle test the wiring and connectors.
    5. Look for the data to change or for the DTC to reset during the wiggle test.
    6. Refer to any Technical Service Bulletins that may apply.

      Were any problems found?

      Yes 

      No