Diagnostic Test

1) DTC IS ACTIVE
Turn the ignition on.

With the scan tool, Clear DTCs in the Powertrain Control Module (PCM).

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 can result in personal injury or death.

Increase engine speed by pressing the accelerator pedal. Do not exceed 3500 rpm.

With the scan tool, select View DTCs.

Is the status Active for this DTC?

Yes
1. Go to 2).
No
1. Refer to *CHECKING FOR AN INTERMITTENT DTC .
2) (Z904) GROUND CIRCUIT OPEN OR HIGH RESISTANCE

Fig 1: Checking Generator Field Ground Circuit
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Generator connector.

Measure the resistance between ground and the (Z904) Ground circuit in the Generator harness connector.

Is the resistance below 5.0 ohms?

Yes
1. Go to 3).
No
1. Repair the (Z904) Ground circuit for an open circuit or high resistance.
2. Perform *PCM VERIFICATION TEST .
3) (K20) GEN FIELD CONTROL CIRCUIT SHORTED TO VOLTAGE

Fig 2: Checking Generator Field Control Circuit
Courtesy of CHRYSLER LLC

Turn the ignition off.

Disconnect the Powertrain Control Module (PCM) connector.

Turn the ignition on.

Measure the voltage of the (K20) Gen Field Control circuit in the Generator harness connector.

Is there any voltage present?

Yes
1. Repair the (K20) Gen Field Control circuit for a short to voltage.
2. Perform *PCM VERIFICATION TEST .
No
1. Go to 4).
4) (K20) GEN FIELD CONTROL CIRCUIT SHORTED TO GROUND

Fig 3: Checking Generator Field Control Circuit
Courtesy of CHRYSLER LLC

Turn the ignition off.

Measure the resistance between ground and the (K20) Gen Field Control circuit in the Generator harness connector.

Is the resistance above 100 ohms?

Yes
1. Go to 5).
No
1. Repair the (K20) Gen Field Control circuit for a short to ground.
2. Perform *PCM VERIFICATION TEST .
5) (K20) GEN FIELD CONTROL CIRCUIT OPEN OR HIGH RESISTANCE

Fig 4: Checking Generator Field Control Circuit
Courtesy 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 (K20) Gen Field Control circuit between the Generator harness connector and the appropriate terminal of special tool #8815.

Is the resistance below 5.0 ohms?

Yes
1. Go to 6).
No
1. Repair the (K20) Gen Field Control circuit for an open circuit or high resistance.
2. Perform *PCM VERIFICATION TEST .
6) GENERATOR

Fig 5: Checking Generator Field Control Circuit
Courtesy of CHRYSLER LLC

Connect the Powertrain Control Module (PCM) connector.

Turn the ignition on.

Connect a 12 volt test light between the (Z904) Ground circuit and the (K20) Gen Field Control circuit in the Generator harness connector.

With the scan tool, actuate the Alternator Field Control State.

NOTE: The voltage supplied to the solenoid circuit during the actuation will be less than battery voltage. The test light should be illuminated, but not as bright as a direct connection to the battery.

Is the test light illuminated during the actuation?

Yes
1. Replace the Generator in accordance with the Service Information.
2. Perform *PCM VERIFICATION TEST .
No
1. Go to 7).
7) POWERTRAIN CONTROL MODULE (PCM)
Using the wiring diagram/schematic as a guide, inspect the wiring and connectors between the Generator 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 and program the Powertrain Control Module (PCM) in accordance with the Service Information.
2. Perform *PCM VERIFICATION TEST .