DTC P0622: GENERATOR FIELD NOT SWITCHING PROPERLY Dodge Ram Wagon B1500

Note. For connector terminal identification, see CONNECTOR IDENTIFICATION . For circuit identification and wiring diagram, see RAM VAN & RAM WAGON wiring diagram in WIRING DIAGRAMS article.

Note. DTC P0622: GENERATOR FIELD NOT SWITCHING PROPERLY is monitored with engine running. DTC may be stored in Powertrain Control Module (PCM) when PCM senses attempts to regulate generator field indicate no result during monitoring. Possible causes are: defective generator, defective PCM, defective connector or defective wiring.

Scheme 30

1. Turn ignition on, with engine off. Using scan tool, read and record DTCs and FREEZE FRAME data, and then erase DTCs. Turn ignition off. Visually inspect related connectors for corroded, damaged, pushed-out or miswired terminals. Clean and/or repair connectors as necessary. Turn ignition on, with engine off. Using scan tool, actuate Generator (GEN) field driver circuit. Using a 12-volt test light connected to ground, probe GEN field driver circuit (Dark Green/White wire) at back of generator. If test light illuminates brightly, go to next step. If test light does not illuminate brightly, repair GEN field driver circuit for open or high resistance. Perform TEST VER-3A.
2. Turn ignition on, with engine off. Using scan tool, actuate Generator (GEN) field driver circuit. Using a 12-volt test light connected to ground, probe GEN field driver circuit (Dark Green/White wire) at back of generator. If test light blinks, go to next step. If test light does not blink, go to step 5).
3. Turn ignition on, with engine off. Using scan tool, actuate GEN field driver circuit. Read and record DTCs. Wiggle wiring harness from generator to PCM while actuating GEN field driver circuit. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. If DTC P0622: GENERATOR FIELD NOT SWITCHING PROPERLY returns, repair wiring harness where wiggling caused DTC to return. Perform TEST VER-3A. If DTC P0622: GENERATOR FIELD NOT SWITCHING PROPERLY does not return, go to next step.
4. Turn ignition off. Visually inspect related connectors and wiring harness for damage. Repair connectors and wiring harness as necessary. Perform TEST VER-3A. If connectors and wiring harness are okay, test is complete.
5. Turn ignition off. Disconnect PCM connectors. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Disconnect GEN field terminals connector at back of generator. Disconnect battery. Clean and/or repair connectors as necessary. Using an ohmmeter, check resistance across GEN field terminals. 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.
6. Ensure ignition is off. Ensure PCM and GEN field terminal connectors are still disconnected. Ensure battery is still disconnected. Using ohmmeter, check resistance of GEN field driver circuit (Dark Green/White wire) between PCM and generator. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open GEN field driver circuit. Perform TEST VER-3A.
7. Ensure ignition is off. Ensure PCM and GEN field terminal connectors are still disconnected. Ensure battery is still disconnected. Using ohmmeter, check resistance between ground and GEN connector, field driver circuit (Dark Green/White wire). If resistance is less than 5 ohms, repair field driver circuit for short to ground. Perform TEST VER-3A. If resistance is 5 ohms or more, go to next step.
8. At this time, PCM is assumed to be defective. Replace PCM. Perform TEST VER-3A.