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Home >> Buick >> 2018 >> LaCrosse Base >> Repair and Diagnosis >> Hybrid/Electric Powertrain >> Electric Converters and Controllers >> Hybrid/EV Control System >> Diagnostic Information and Procedures >> DC Power Conversion Test >> Circuit/System Verification
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Circuit/System Verification

    NOTE:

    To accurately diagnose the charging system, the C1 Battery must be fully charged and capable of passing the Battery Inspection/Test.

  1. Perform the Battery Inspection/Test .
  2. NOTE:

    The engine must be started at least once during a key cycle to enable high voltage and the 14 V Power Module. The 14 V Power Module and high voltage will remain enabled during any subsequent Autostops.

  3. Engine running.
  4. Verify that no DTCs are set that would cause a high voltage system concern or a 12V charging system concern.
    • Go to next step: If no applicable DTCs are set 
  5. With a scan tool, verify the Hybrid/EV Powertrain Control Module 2 parameters Hybrid/EV Battery Positive Contactor Command and Hybrid/EV Battery Negative Contactor Command each indicate Closed.
    • Go to next step: If the contactors are commanded Closed 
  6. Ignition Off.
  7. Measure and record the C1 Battery Voltage at the C1 Battery terminals. The C1 Battery Voltage should stabilize within a few minutes of turning the ignition/vehicle OFF.
  8. Engine running, daytime running lamps and all accessories OFF.
  9. Measure and record the C1 Battery Voltage at the C1 Battery terminals. The voltage should be at least 1 V greater than the voltage measured with the engine OFF, but less than 15.5 V.
    • If not within the specified range 

      Refer to Circuit/System Testing.

    • Go to next step: If within the specified range 
  10. All OK.