DTC P0622-A: Generator Field Not Switching Properly

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

Inspect all connectors for corrosion or spread terminals before performing test procedure. Using scan tool, erase DTCs. Using scan tool, actuate generator field driver circuit. Using a 12-volt test light, backprobe generator field connector ASD relay output circuit. Generator field connector is located on back of generator. See GENERATOR FIELD CONNECTOR WIRE IDENTIFICATION table. If test light is brightly illuminated, go to next step. If test light is not brightly illuminated, repair open or high resistance in ASD relay output circuit. Perform TEST VER-3A: CHARGING VERIFICATION .
Using a 12-volt test light, backprobe generator field connector generator field driver circuit. See GENERATOR FIELD CONNECTOR WIRE IDENTIFICATION table. If test light shifts from bright to dim, go to next step. If test light does not shift from bright to dim, go to step 5.
Condition to set trouble code is not present at this time. GENERATOR FIELD NOT SWITCHING PROPERLY DTC sets when Powertrain Control Module (PCM) tries to regulate generator field with no result during monitoring. Possible causes are: field driver circuit open or shorted, generator internal open or short or PCM failure. Go to next step.
Wiggle wiring harness from generator to PCM. Using scan tool, read DTCs with actuator test still running. If generator field driver circuit failure returned, repair wiring harness as necessary where wiggling caused problem to appear. Perform TEST VER-3A: CHARGING VERIFICATION . If generator field driver circuit failure did not appear, no problem is found at this time. See INACTIVE TROUBLE CODE CONDITION under SELF-DIAGNOSTICS. Test is complete. Perform TEST VER-3A: CHARGING VERIFICATION .
Using scan tool, stop generator field driver activation. Turn ignition off. Disconnect Powertrain Control Module (PCM) connector. Disconnect generator field connector from back of generator. Using an ohmmeter, check resistance of generator field driver circuit between generator field driver connector and PCM connector terminal No. 8. See GENERATOR FIELD CONNECTOR WIRE IDENTIFICATION table and PCM CONNECTOR WIRE IDENTIFICATION table. If resistance is 5 ohms or more, repair open generator field driver circuit. Perform TEST VER-3A: CHARGING VERIFICATION . If resistance is less than 5 ohms, go to next step.
With generator field connector disconnected, using an ohmmeter, check resistance between generator field terminals on generator. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair generator as necessary. Perform TEST VER-3A: CHARGING VERIFICATION .
Using an ohmmeter, check resistance of generator field connector generator field driver circuit. See GENERATOR FIELD CONNECTOR WIRE IDENTIFICATION table. If resistance is less than 5 ohms, repair short to ground on generator field driver circuit. Perform TEST VER-3A: CHARGING VERIFICATION . If resistance is 5 ohms or more, replace Powertrain Control Module (PCM). Perform TEST VER-3A: CHARGING VERIFICATION .

GENERATOR FIELD CONNECTOR WIRE IDENTIFICATION

Application		Wire Color
Generator Field Driver Circuit		Dark Green
ASD Relay Output Circuit		Orange/Dark Green

PCM CONNECTOR WIRE IDENTIFICATION

Application		Wire Color
PCM Terminal No. 8
Generator Field Driver Circuit		Dark Green