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Test C: System Overcharges

  1. Check The Fault Codes In The 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. If no DTCs exist, go to next step. If any DTCs exist, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS in ENGINE PERFORMANCE.

  2. Check The Battery Voltage

    Turn ignition off. Disconnect the diagnostic tool. 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 36 (Yellow/White)

    Turn ignition off. Disconnect: generator connector C102a or C102c. Measure the voltage between the generator connector C102a or C102c terminal No. 3 (Yellow/White wire), harness side and ground. Is the voltage within 0.5 volt from battery voltage? If yes, reconnect generator connector and go to next step. If no, repair the circuit for high resistance. Test the system for normal operation.

  4. Check The Generator PIDs

    Connect New Generation Star (NGS) tester to Data Link Connector (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 The Generator Integrity

    Turn ignition off. Disconnect: generator connector C102a or C102c. Start engine. If the generator communication lines are disconnected, the generator will self-excite if it is operated at approximately 2,000 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 2,000 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 for normal operation.

  6. Check For Correct PCM Operation

    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. Is the concern still present? If yes, install a new PCM. See COMPUTERIZED ENGINE CONTROLS in appropriate REMOVAL & INSTALLATION in ENGINE PERFORMANCE. Repeat the PCM self-test. If no, 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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