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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 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 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 Volt Battery Pack will utilize an exchange program. Please consult the most recent revision of bulletin/PI #PIP4841, available in Service Information (SI), for a list of approved Volt Battery Pack service procedures. Components that may be removed and serviced without exchanging the complete battery pack are identified in the bulletin/PI. Please contact the GM Technical Assistance Center (1-877-446-8227) if you have any questions.
WARNING: This diagnostic has NOT been validated on-vehicle. Follow all safety protocol and utilize all appropriate personal protective equipment to ensure your safety. Failure to follow the procedures exactly as written may result in serious injury or death.
    NOTE: Use the schematic to identify the following:
    • The control module locations on the battery energy control module dedicated serial data circuits
    • The control module B+, ignition, ground, communication enable and serial data circuit terminals
  1. Perform the High Voltage Disabling procedure before proceeding with this diagnostic. Refer to High Voltage Disabling .
  2. Reconnect the 12 V battery.
  3. Ignition OFF, disconnect the X1 harness connector at the K112B hybrid battery interface control module 2.
  4. 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 10 Ω between the low reference circuit terminal 12 X1 and ground.
    • If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K112A hybrid battery interface control module 1.
  5. Ignition ON, test for 4.8-5.2 V between the 5 V reference circuit terminal 9 X1 and ground.
    • If less than the specified range, test the 5 V reference circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K112A hybrid battery interface control module 1.
    • If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K112A hybrid battery interface control module 1.
  6. Ignition ON, test for 4.8-5.2 V between the high voltage fault signal circuit terminal 13 X1 and ground.
    • If less than the specified range, test the high voltage fault signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K112A hybrid battery interface control module 1.
    • If greater than the specified range, test the high voltage fault signal circuit for a short to voltage. If the circuit tests normal, replace the K112A hybrid battery interface control module 1.
  7. Ignition OFF, disconnect the X1 harness connector at the K112A hybrid battery interface control module 1.
  8. 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 1 Ω in each serial data circuit between the K112B hybrid battery interface control module 2 and K112A hybrid battery interface control module 1.
    • K112B hybrid battery interface control module 2 serial data circuit terminal 10 X1 and K112A hybrid battery interface control module 1 serial data circuit terminal 17 X1
    • K112B hybrid battery interface control module 2 serial data circuit terminal 11 X1 and K112A hybrid battery interface control module 1 serial data circuit terminal 16 X1
    • If greater than the specified range, test the serial data circuit for an open/high resistance between the K112B hybrid battery interface control module 2 and the K112A hybrid battery interface control module 1.
    9. NOTE: The K112B hybrid battery interface control module 2 has a loop in the harness that connects its 5 V reference circuit terminal 19 X1 to its signal ground circuit terminal 6 X1. Test this circuit for the appropriate failure mode short to voltage, short to ground, or open/high resistance prior to replacing the K112B hybrid battery interface control module 2.
  9. If all circuits test normal, replace the K112B hybrid battery interface control module 2.
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