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Test D: Warning Indicator On With Engine Running, System Is Charging

  1. Check For Fault Codes In PCM

    Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition on. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If DTC P0622 was retrieved, follow the NO direction. Are any PCM DTCs recorded? If no, go to next step. If yes, perform appropriate test in accordance with DTC retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

  2. Check System For Overcharging

    Start engine. With engine running and all accessories turned off, measure voltage between battery terminals while varying engine speed. Is the voltage greater than 15.5 volts? If yes, perform TEST C: SYSTEM OVERCHARGES (MORE THAN 15 VOLTS)  . If no, go to next step.

  3. Check Charging System PIDs

    Enter MONITOR PCM PIDs diagnostic mode on the diagnostic tool. 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, see appropriate ANALOG INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT to diagnose the charging system warning indicator.

  4. Check Generator Output

    Check generator output. See GENERATOR LOAD TEST  and GENERATOR NO-LOAD TEST  under ON-VEHICLE TESTING. Did the generator pass the component tests? If yes, go to next step. If no, install a new generator. See GENERATOR  under REMOVAL & INSTALLATION. Repeat the self-test. Test the system for normal operation.

  5. Check For Correct PCM Operation

    Disconnect PCM connector. Check for corrosion and pushed-out pins. Connect PCM connector and make sure it seats correctly. Operate the system and verify the concern is still present. Is the concern still present? If yes, install a new PCM. See COMPUTERIZED ENGINE CONTROLS in appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. Test the system for normal operation. If no, the system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. Clear the DTCs. Repeat the self-test. Test the system for normal operation.
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