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Home >> Dodge and Ram >> 2002 >> Durango Base, 5.9 Z, 4WD, Part Time >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics - NGC >> Diagnostic Tests >> DTC P0622: Generator Field Control Circuit >> Testing
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DTC P0622: Generator Field Control Circuit: Testing

  1. Turn the ignition on, with the engine off. With the DRBIII(R), read DTCs and record the related Freeze Frame data. Is the Good Trip counter displayed and equal to zero? If yes, go to next step. If no, see INTERMITTENT FAILURES  under ON-BOARD DIAGNOSTICS.
  2. Turn the ignition off. Disconnect the Generator Field harness connector. Connect a 12-volt test light between the Generator Field Control circuit and the Ground circuit in the Generator Field harness connector. Turn the ignition on, with the engine off. With the DRBIII(R), actuate the Generator Field Control circuit. Does the test light illuminate brightly and flash? If yes, stop all actuations and replace the Generator. If no, stop all actuations and go to next step.
  3. Turn the ignition off. Using a 12-volt test light connected to 12 volts, probe the Ground circuit in the Generator Field harness connector. Does the test light illuminate brightly? If yes, go to next step. If no, repair the open in the Ground circuit.
  4. Turn the ignition off. Disconnect the PCM harness connectors. Measure the voltage on the Generator Field Control circuit in the Generator Field harness connector. Is the voltage more than one volt? If yes, repair the short to voltage in the Generator Field Control circuit. If no, go to next step.
  5. Measure the resistance between ground and Generator Field Control circuit in the Generator Field harness connector. Is the resistance less than 100 ohms? If yes, repair the short to ground in the Generator Field Control circuit. If no, go to next step.
    6. CAUTION: DO NOT probe the PCM harness connectors. Probing the PCM harness connectors will damage the PCM terminals resulting in poor terminal-to-pin connection. Install Miller Special Tool (8815) to perform diagnosis.
  6. Measure the resistance of the Generator Field Control circuit from the Generator Field harness connector to the appropriate terminal in the Miller Special Tool. Is the resistance less than 5.0 ohms? If yes, go to next step. If no, repair the open in the Generator Field Control circuit.
    7. NOTE: Before continuing, check the PCM harness connector terminals for corrosion, damage, or terminal push-out. Repair as necessary.
  7. There are no possible causes remaining, replace the PCM.
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