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Circuit/System 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.

Before working on any high voltage system, be sure to wear the following Personal Protection Equipment:

  • Safety glasses with appropriate side shields when within 15 meters (50 feet) of the vehicle, either indoors or outdoors.
  • Certified and up-to-date Class "0" Insulation gloves rated at 1000V with leather protectors.
    • Visually and functionally inspect the gloves before use.
    • Wear the Insulation gloves with leather protectors at all times when working with the high voltage battery assembly, whether the system is energized or not.

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

WARNING:

The eAssist battery pack assembly will utilize an exchange program. Please consult the most recent revision of bulletin/PI# PIC5520, available in Service Information (SI), for a list of approved eAssist battery pack assembly service procedures. Components that may be removed and serviced without exchanging the complete battery pack assembly are identified in the bulletin/PI. Please contact the GM Technical Assistance Center (1-877-446-8227) if you have any questions.

    NOTE:

    Use the schematic to identify the following:

    • Control module location on the powertrain high speed GMLAN serial data circuits
    • Control module B+, ignition, ground, accessory wake up serial data, and serial data circuit terminals.
  1. Perform the High Voltage Disabling procedure. Refer to High Voltage Disabling .
  2. Reconnect the 12 V battery.
  3. Ignition OFF, disconnect the low voltage harness connector at the K59 starter/generator control module.
  4. Test for less than 10 Ω between the K59 starter/generator control module case and ground.
    • If greater than the specified range, check the ground connection at the housing.
  5. If equipped, ignition ON, verify that a test lamp illuminates between each B+ circuit terminal and ground.
    • If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the control circuits of the K59 starter/generator control module for a short to ground. If the circuits test normal, replace the K59 starter/generator control module.
  6. If equipped, ignition ON, verify that a test lamp illuminates between each ignition circuit terminal and ground.
    • If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit fuse is open, test the control circuits of the K59 starter/generator control module for a short to ground. If the circuits test normal, replace the K59 starter/generator control module.
  7. If equipped, ignition ON, verify that a test lamp illuminates between the accessory wake up serial data circuit terminal and ground.
    • If the test lamp does not illuminate, test the entire circuit, including the B+ circuit to the K9 body control module, for an open/high resistance or short to ground. If the circuits test normal, replace the K9 body control module.
  8. Ignition OFF, disconnect the harness connector at the control module setting the DTC.
  9. Ignition OFF and all vehicle systems OFF, all keys at least 3 meters away from vehicle, all access doors closed. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 2 Ω in each powertrain high speed GMLAN serial data circuit between the K59 starter/generator control module and the control module setting the DTC.
    • If greater than the specified range, test the serial data circuit for an open/high resistance between the K59 starter/generator control module and the control module setting the DTC.
  10. If all circuits test normal, replace the K59 starter/generator control module.
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