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Circuit/System Testing

WARNING: This page is about a different car, the 2011 GMC Yukon, 2011 Chevrolet Tahoe, and 2011 Cadillac Escalade. However, it is still accessible from the selected car via links, so may be relevant.

DC Circuit Testing

    WARNING:

    Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

    The High Voltage Disabling procedure will perform the following tasks:

    • Identify how to disable high voltage.
    • Identify how to test for the presence of high voltage.
    • Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

    Failure to follow the procedures exactly as written may result in serious injury or death.

  1. Perform the High Voltage Disabling procedure for servicing at the drive motor generator control module cable connections.
  2. Remove the air conditioning control module high voltage cable connector from the drive motor generator power inverter module. Protect the terminal ends immediately with the EL-48569  terminal covers and UL® Listed or equivalent insulation tape rated at a minimum of 600 volts.
  3. Temporarily install the drive motor generator control module high voltage distribution cover.
  4. Install the drive motor generator control module sight shield.
  5. Install the high voltage manual disconnect lever.
  6. Connect the 12 volt battery. Refer to Battery Negative Cable Disconnection and Connection .
  7. Ignition ON, engine OFF, within 5 seconds of ignition ON, observe the hybrid powertrain control module 300V Circuit parameter and compare it to both data parameters listed below. Both motor parameters should be at least 20 V less than the hybrid powertrain control module 300V circuit parameter.
    • Motor 1 Isolation Voltage
    • Motor 2 Isolation Voltage
    • If both motor parameters pass, replace the air conditioning control module.
    8. WARNING:

    Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

    The High Voltage Disabling procedure will perform the following tasks:

    • Identify how to disable high voltage.
    • Identify how to test for the presence of high voltage.
    • Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

    Failure to follow the procedures exactly as written may result in serious injury or death.

  8. Perform the High Voltage Disabling procedure for servicing at the drive motor generator control module cable connections.
  9. Disconnect the 300 V Battery Positive and Negative Cable Assembly connector at the drive motor generator power inverter module.
  10. Remove and retain the cable mounting block O-ring. Re-install the O-ring after testing is complete.
  11. Disconnect the X1 harness connector at the drive motor generator power inverter module.
  12. Connect the EL-48458  test toolat the 300 V Battery Positive and Negative Cable Assembly and the drive motor generator power inverter module X1 harness connector. Refer to High Voltage System Diagnosis (EL-48458)  for Installation Procedure, set-up, and usage instructions.
  13. Using the EL-48458  test tool move the high voltage contactor switch to the CLOSED position. The greater than 60V lamp should be illuminated.
    14. NOTE:

    The scan tool isolation test output control could cause a loss of communication condition with the battery energy control module if utilized incorrectly. If the loss of communication condition occurs, you must remove the battery energy control module fuse from the auxiliary fuse block in order for the battery energy control module to re-initialize. To avoid causing this battery energy control module condition, ensure the following conditions are met prior to activating the scan tool output control:

    • External 12 V battery chargers are disconnected from the vehicle.
    • The output control limits are not violated when this output control is initiated.
  14. Ensure the output control limits are not violated when this output control is initiated. Refer to Drive Motor Generator Battery Control Module Scan Tool Information for the control limits.
  15. Activate the battery energy control module 300V Isolation Test output control with the scan tool. The Isolation Test should complete within 1 minute. Observe the 300V Isolation Test Status scan tool parameter. The test status should display FAIL when the test is completed.
    • If the 300V Isolation Test displays PASS, replace the drive motor generator power inverter module and the accessory DC power control module.
  16. Verify high voltage is not present before disconnecting the EL-48458  test toolfrom the vehicle. Refer to High Voltage System Diagnosis (EL-48458)  for Removal Procedure.
    17. WARNING:

    Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

    The High Voltage Disabling procedure will perform the following tasks:

    • Identify how to disable high voltage.
    • Identify how to test for the presence of high voltage.
    • Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

    Failure to follow the procedures exactly as written may result in serious injury or death.

  17. Perform the High Voltage Disabling procedure for servicing at the drive motor generator battery.
  18. Disconnect the 300V Battery Positive and Negative Cable Assembly connector at the drive motor generator battery assembly. Protect the terminal ends immediately with the EL-48569  terminal covers and UL® Listed or equivalent insulation tape rated at a minimum of 600 volts.
  19. Using the extension harness connect the EL-48458  test toolat the hybrid battery 300 V positive and negative terminals.
  20. Connect the EL-48458  test toolthe drive motor generator power inverter module X1 harness connector. Refer to High Voltage System Diagnosis (EL-48458)  for Installation Procedure, set-up, and usage instructions.
    21. NOTE:

    The drive motor generator control module sight shield and the drive motor generator battery terminal cover must be reinstalled in order to complete the HVIC current loop. The battery energy control module will not close the high voltage contactor relays if an open high voltage interlock circuit condition is detected.

  21. Using the EL-48458  test toolmove the high voltage contactor switch to the CLOSED position. The greater than 60V lamp should be illuminated.
    22. NOTE:

    The scan tool isolation test output control could cause a loss of communication condition with the battery energy control module if utilized incorrectly. If the loss of communication condition occurs, you must remove the battery energy control module fuse from the auxiliary fuse block in order for the battery energy control module to re-initialize. To avoid causing this battery energy control module condition, ensure the following conditions are met prior to activating the scan tool output control:

    • External 12 V battery chargers are disconnected from the vehicle.
    • The output control limits are not violated when this output control is initiated.
  22. Verify the output control limits are not violated when this output control is initiated. Refer to Drive Motor Generator Battery Control Module Scan Tool Information for the control limits.
  23. Activate the battery energy control module 300V Isolation Test output control with the scan tool. The Isolation Test should complete within 1 minute. Observe the 300V Isolation Test Status scan tool parameter. The test status should display FAIL when the test is completed.
    • If the 300V Isolation Test displays PASS, replace the 300 V Battery Positive and Negative Cable Assembly.
  24. If the Isolation Test Status displays FAIL the loss of isolation has occurred within the hybrid battery between the switched side of the high voltage contactors and the hybrid battery high voltage terminal assembly. Replace or repair the drive motor generator battery.

AC Circuit Testing

    WARNING:

    Always perform the High Voltage Disabling procedure prior to servicing any High Voltage component or connection. Personal Protection Equipment (PPE) and proper procedures must be followed.

    The High Voltage Disabling procedure will perform the following tasks:

    • Identify how to disable high voltage.
    • Identify how to test for the presence of high voltage.
    • Identify condition under which high voltage is always present and personal protection equipment (PPE) and proper procedures must be followed.

    Failure to follow the procedures exactly as written may result in serious injury or death.

  1. Perform the High Voltage Disabling procedure for servicing at the drive motor generator control module cable connections.
  2. Remove the 3-phase cable assembly from the T6 drive motor generator control module distribution box. Refer to Generator Control Module 3-Phase Cable Assembly Replacement .
  3. Test for infinite resistance between each of the AC circuit terminals listed below and ground:
    • Drive motor 1st position phase U terminal
    • Drive motor 1st position phase V terminal
    • Drive motor 1st position phase W terminal
    • Drive motor 2nd position phase U terminal
    • Drive motor 2nd position phase V terminal
    • Drive motor 2nd position phase W terminal
      • If not the specified value, test the AC circuit for a short to ground or a short between the AC circuit terminals and the aluminum cable mounting block. If the circuit tests normal replace the appropriate M15 drive motor with generator assembly.
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