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Home >> Dodge and Ram >> 2001 >> Durango 5.9 Z, 4WD, Part Time >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0622: Generator Field Not Switching Properly >> Testing
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DTC P0622: Generator Field Not Switching Properly: Testing

  1. Turn ignition on, engine off. Using scan tool, actuate GENERATOR FIELD DRIVER circuit. Using 12-volt test light, check for voltage by backprobing generator harness connector terminal No. 2 (Dark Green wire on 4.7L or Dark Blue wire on 5.9L). If test light flashes on and off, go to next step. If test light does not flash on and off, stop actuation of generator field driver and go to step  3.
  2. Ensure ignition is on with engine off and GENERATOR FIELD DRIVER circuit is still actuated by scan tool. Wiggle wiring harness and connectors between PCM and generator harness connector. PCM is located in engine compartment on passenger-side inner fender panel. Using scan tool, read DTCs. If DTC P0622: GENERATOR FIELD NOT SWITCHING PROPERLY does not exist, test is complete. If DTC P0622: GENERATOR FIELD NOT SWITCHING PROPERLY exists, repair wiring harness or connector that caused DTC to return.
  3. Ensure ignition is on, engine off. Using scan tool, read DTCs. Record all DTCs and FREEZE FRAME DATA. Using scan tool, clear DTCs from PCM. Turn ignition off. Inspect PCM connectors and generator harness connector for corroded, damaged or pushed-out terminals. PCM is located in engine compartment on passenger-side inner fender panel. Clean and/or repair connectors as necessary. Using scan tool, actuate GENERATOR FIELD DRIVER circuit. Using DVOM, measure voltage by backprobing between generator harness connector terminal No. 1 (White/Dark Blue wire) and ground. If voltage is more than 10 volts, go to next step. If voltage is 10 volts or less, repair open generator field source circuit to generator. See appropriate wiring diagram in GENERATORS & REGULATORS - TRUCKS & RWD VANS article.
  4. Turn ignition off. Disconnect PCM connectors. Disconnect generator 2-pin connector. Using DVOM, measure resistance between ground and PCM harness connector C2 terminal No. 10 (Dark Green wire on 4.7L or Dark Blue wire on 5.9L). See Figure. If resistance is 5 ohms or more, go to next step. If resistance is less than 5 ohms, repair short to ground in Dark Green wire or Dark Blue wire between PCM and generator.
  5. Ensure ignition is off and generator 2-pin connector and PCM connectors are still disconnected. Using DVOM, measure resistance of Dark Green wire (4.7L) or Dark Blue wire (5.9L) between PCM harness connector C2 terminal No. 10 and generator harness connector terminal No. 2. If resistance is less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Dark Green wire or Dark Blue wire between PCM and generator.
  6. Using DVOM, measure resistance between both generator connector 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.
  7. At this time, PCM is assumed to be defective. Replace PCM.
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