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Test C: System Overcharges

  1. Check For Fault Codes In PCM

    Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition switch to RUN position. Using NGS tester, perform Powertrain Control Module (PCM) self-test. Do any DTCs exist? If yes, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS in ENGINE PERFORMANCE. If no, go to next step.

  2. Check Battery Voltage

    Turn ignition off. Disconnect NGS tester. Start engine. With the engine running and all accessories turned off, measure the voltage at the battery while varying the engine RPM. Is the voltage greater than 15.5 volts? If yes, go to next step. If no, go to step  4 .

  3. Check For Voltage Drop In Circuit (Yellow/White Wire)

    Turn ignition off. Disconnect generator 3-pin connector. Measure the voltage between the generator connector terminal No. 3 (Yellow/White wire) and ground. See Figure or Figure . Is the voltage within 0.5 volt from battery voltage? If yes, reconnect the generator connector and go to next step. If no, repair the circuit for high resistance. Test the system for normal operation.

  4. Check Generator PIDs

    Connect generator connector. Connect the NGS tester to DLC. Start engine. With the engine running, monitor the generator output fault PID in the PCM. Does the PID read YES? If yes, go to next step. If no, go to step  6 .

  5. Check Generator Integrity

    Turn ignition off. Disconnect generator 3-pin connector. Start engine. If the generator communication lines are disconnected, the generator will self-excite if it is operated at approximately 2000 RPM for a momentary period of time. It will then operate in a default mode at 13.5 volts until the engine is turned off. With the engine running at approximately 2000 RPM, measure the battery voltage. Is the battery voltage approximately 13.5 volts? If yes, go to next step. If no, install a new generator. See GENERATOR  under REMOVAL & INSTALLATION. Test the system for normal operation.

  6. Check For Correct PCM Operation

    Disconnect all PCM connectors. Check for corrosion and pushed-out pins. Connect any disconnected connectors. Make sure all other system connectors are fully seated. Operate the system and verify the concern is still present. If the concern still present, install a new PCM. See appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. Repeat the PCM self-test. Test the system for normal operation. If concern is not still present, the system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. Clear the DTCs. Repeat the self-test.
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