Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Diagnostic Test
- ACTIVE DIAGNOSTIC TROUBLE CODE (DTC)
- 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.
- Increase engine speed by pressing the accelerator pedal. Do not exceed 3500 RPM.
- Using the scan tool, read the active DTCs.
Is the DTC Active at this time?
Yes
- Go To 2
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- Start the engine and allow it to reach operating temperature.
- GENERATOR OPERATION
- Turn the ignition off.
- Disconnect the Generator harness connector.
- Using a 12-volt test light connected to ground, probe the (K20) Generator Field Control circuit in the Generator Field harness connector.
- 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.
- 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
- Verify that there is good pin to terminal contact in the Generator and Powertrain Control Module connectors. If OK, replace the Generator. Refer to GENERATOR, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 3
- (K20) GEN FIELD CIRCUIT SHORTED TO VOLTAGE
- Turn the ignition off.
- Disconnect the C2 PCM harness connector.
- Ignition on, engine not running.
- Measure the voltage on the (K20) Gen Field Control circuit in the Generator Field harness connector.
Is there any voltage present?
Yes
- Repair the short to voltage in the (K20) Gen Field Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 4
- (K20) GEN FIELD CIRCUIT OPEN
Courtesy of CHRYSLER GROUP, LLC
- Turn the ignition off.
- 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
- Repair the open in the (K20) Gen Field Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
- (K20) GEN FIELD CIRCUIT SHORTED TO GROUND
- Measure the resistance between ground and the (K20) Gen Field Control circuit in the Generator Field harness connector.
Is the resistance below 100 Ohms?
Yes
- Repair the short to ground in the (K20) Gen Field Control circuit.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Go To 6
- Measure the resistance between ground and the (K20) Gen Field Control circuit in the Generator Field harness connector.
- 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. Verify that there is good pin to terminal contact in the Generator and Powertrain Control Module connectors.
- Perform any Technical Service Bulletins that may apply.
Were there any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
No
- Replace and program the Powertrain Control Module in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL, REMOVAL .
- Perform the POWERTRAIN VERIFICATION TEST. Refer to STANDARD PROCEDURE .
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.