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Circuit/System Testing

WARNING: This page is about a different variant/trim than selected.
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.

  1. Ignition OFF, disconnect the harness connector at the B22 brake pedal position sensor and disconnect the X1 harness connector at the A15 starter/generator, ignition ON.
  2. Test for 4.8-5.2 V between the A15 starter/generator 5 V reference circuit terminal 12 X1 and ground.
    • If less than 4.8 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K59 starter/generator control module.
    2. Test for infinite resistance between the A15 starter/generator 5 V reference circuit terminal 12 X1 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for infinite resistance between the B22 brake pedal position sensor 5 V reference circuit terminal 6 and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    4. Test for less than 2 Ω in the A15 starter/generator 5 V reference circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K59 starter/generator control module.
    • If greater than 5.2 V 
    1. Ignition OFF, disconnect the X2 harness connector at the K59 starter/generator control module.
    2. Test for less than 1 V between the A15 starter/generator 5 V reference circuit terminal 12 X1 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V
    3. Test for less than 1 V between the B22 brake pedal position sensor 5 V reference circuit terminal 6 and ground.
      • If 1 V or greater, repair the short to voltage on the circuit.
      • If less than 1 V, replace the K59 starter/generator control module.
    • If between 4.8-5.2 V 
  3. Ignition OFF, connect the harness connector at the A15 starter/generator, ignition ON.
  4. Verify DTC P0641 does not set while operating the vehicle within the conditions for running the DTC.
    • If the DTC sets 

      Replace the A15 starter/generator.

    • If the DTC does not set 
  5. Test or replace the B22 brake pedal position sensor.
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