DTC P0622: Generator Field Not Switching Properly

NOTE: For connector terminal ID, see CONNECTOR IDENTIFICATION . For wiring diagram, see WIRING DIAGRAMS article.

NOTE: Generator field switching is monitored when ignition is on and engine is running. DTC may be stored in Powertrain Control Module (PCM) when PCM tries to regulate the generator field with no results. Possible causes are: generator field driver circuit open or shorted, defective generator, defective PCM, defective Auto Shutdown (ASD) relay circuit, or defective connectors or wiring.

Turn ignition on with engine off. Using scan tool, actuate generator field driver. Using voltmeter, check voltage by backprobing terminal No. 1 (Dark Green/Orange wire) in the round 2-wire connector at rear of the generator.
If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open circuit on Dark Green/Orange wire from generator to ASD relay. ASD relay is located in power distribution center at driver's side front corner of engine compartment, near battery. Perform TEST VER-3A .
Ensure ignition is on with engine off. Using scan tool, actuate generator field driver. Using voltmeter, check voltage by backprobing terminal No. 2 (Dark Green wire) in round 2-wire connector at rear of the generator. If voltage cycles from low voltage to high voltage, go to next step. If voltage does not cycle from low voltage to high voltage, go to step 7.
Shut engine off. Turn ignition on with engine off. Using scan tool, clear DTCs from PCM. Using scan tool, actuate generator field driver. Wiggle wiring harness and connectors from generator to the PCM with generator field driver actuated. PCM is located between driver's side front fender and power distribution center, near battery.
Using scan tool, check for DTCs. If DTC P0622: GENERATOR FIELD NOT SWITCHING PROPERLY does not return, go to next step. If DTC P0622: GENERATOR FIELD NOT SWITCHING PROPERLY returns, repair wiring or connectors as necessary that caused the DTC to return. Perform TEST VER-3A .
Turn ignition off. Inspect wiring and connectors between generator, PCM and ASD relay. ASD relay is located in power distribution center at driver's side front corner of engine compartment, near battery. If no problems exist, test is complete. If any problems exist, repair wiring or connectors as necessary. Perform TEST VER-3A .
Using scan tool, stop actuation of generator field driver. Turn ignition off. Disconnect connectors at PCM. PCM is located between driver's side front fender and power distribution center, near battery.
Disconnect round 2-wire connector at rear of the generator. Using ohmmeter, check resistance between both generator field driver terminals inside the generator. These are the terminals that the round 2-wire connector fits on at rear of the generator. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair or replace generator as necessary. Perform TEST VER-3A .
Ensure connectors are still disconnected at PCM and round 2-wire connector is disconnected at rear of the generator. Using ohmmeter, check resistance between ground and terminal No. 2 (Dark Green wire) in round 2-wire connector that was disconnected at rear of the generator. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground on Dark Green wire between generator and PCM. Perform TEST VER-3A .
Using ohmmeter, check resistance between terminal No. 2 (Dark Green wire) on round 2-wire connector for generator and PCM connector terminal No. 8 (Dark Green wire) on 2.4L, 3.3L and 3.8L, or terminal No. 4 (Dark Green wire) on 3.0L. On all models, if resistance is less than 5 ohms, replace PCM. Perform TEST VER-3A . If resistance is 5 ohms or more, repair generator field driver circuit for an open circuit on Dark Green wire between PCM and generator. Perform TEST VER-3A .