DTC P0622: Generator Field Not Switching Properly
NOTE:
For connector terminal identification, see CONNECTOR IDENTIFICATION
. For circuit identification and wiring diagram, see WRANGLER
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) if PCM senses attempts to regulate generator field indicate no result during monitoring. Possible causes are: defective generator, defective PCM, defective connector or defective wiring.
- Turn ignition on, with engine off. Using scan tool, read and record DTCs and FREEZE FRAME data, and then erase DTCs. Visually inspect related connectors for corroded, damaged, pushed-out or miswired terminals. Clean and/or repair connectors as necessary. Ensure ignition is on, with engine off. Using scan tool, actuate generator (GEN) field driver circuit. Using a voltmeter, backprobe GEN source circuit (Dark Green/Orange wire) at back of generator. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open GEN source circuit between generator and PCM connector. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Perform TEST VER-3A.
- Turn ignition on, with engine off. Using scan tool, read and record DTCs and FREEZE FRAME data, and then erase DTCs. Using scan tool, actuate GEN field driver circuit. Using voltmeter, backprobe GEN field driver circuit (Dark Green wire) at back of generator. If voltage shifts from low to high, go to next step. If voltage does not shift from low to high, go to step 5).
- Ensure ignition is 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. 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.
- 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.
- Turn ignition off. Disconnect GEN field terminals connector at back of generator. See Fig 1 . Clean and/or repair connector 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.
- Turn ignition off. Ensure GEN field terminals connector is still disconnected. Disconnect PCM connectors. PCM is located in engine compartment. See PCM LOCATION table under SYSTEM DIAGNOSTICS. Using ohmmeter, check resistance between ground and GEN connector, field driver circuit (Dark Green wire). If resistance is less than 5 ohms, repair GEN driver circuit for short to ground. Perform TEST VER-3A. If resistance is 5 ohms or more, go to next step.
- Ensure ignition is off. Ensure GEN field terminals connector is still disconnected. Ensure PCM connectors are still disconnected. Using ohmmeter, check resistance of GEN field driver circuit (Dark Green wire) between generator and PCM. 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.
- At this time, PCM is assumed to be defective. Replace PCM. Perform TEST VER-3A.