P0620

P0620-GENERATOR FIELD CONTROL CIRCUIT

For a complete wiring diagram refer to the Wiring Information Electrical Diagrams.

- When Monitored:
Ignition on and ASD1 voltage is greater than 6 volts.

- Set Condition:
When the PCM tries to regulate the generator field with no result during monitoring. Two trip fault.





Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding. Pre-Diagnostic Troubleshooting Procedure.

1. ACTIVE DTC
1. Ignition on, engine not running.
2. With a scan tool, select View DTCs.

Is the DTC Active at this time?

Yes

- Go To 2

No

- Refer to the INTERMITTENT CONDITION Diagnostic Procedure. Checking for an Intermittent DTC.

2. GENERATOR OPERATION




1. Using a 12-volt test light connected to ground, probe the (K20) Generator Field Control circuit in the Generator Field harness connector.
2. Ignition on, engine not running.

NOTE: The DTC needs to be cleared before actuating the Generator Field, if the DTC is not cleared, the Generator Field may not be allowed to actuate.

3. With a scan tool, actuate the Generator Field Driver.

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

Yes

- Replace the Generator.
- Perform the PCM Verification Test. PCM Verification Test.

No

- Go To 3

3. (K20) GEN FIELD CIRCUIT SHORTED BATTERY VOLTAGE




1. Turn the ignition off.
2. Disconnect the C2 PCM 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 the voltage above 1.0 volt?

Yes

- Repair the short to battery voltage in the (K20) Gen Field Control circuit.
- Perform the PCM Verification Test. PCM Verification Test.

No

- Go To 4

4. (K20) GEN FIELD CIRCUIT OPEN
1. Turn the ignition off.
2. Measure the resistance of the (K20) Gen Field Control circuit from the Generator Field harness connector to the PCM 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 PCM Verification Test. PCM Verification Test.

5. (K20) GEN FIELD CIRCUIT SHORTED TO GROUND




1. 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 PCM Verification Test. PCM Verification Test.

No

- Go To 6

6. PCM

NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push out. Repair as necessary.

1. Using the schematics as a guide, inspect the wire harness and connectors. Pay particular attention to all Power and Ground circuits.

Were there any problems found?

Yes

- Repair as necessary.
- Perform the PCM Verification Test. PCM Verification Test.

No

- Replace and program the Powertrain Control Module.
- Perform the PCM Verification Test. PCM Verification Test.