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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 includes the following steps:

  • 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 may result in serious injury or death.

NOTE:

Use the schematics and connector end views to identify the device's ground, B+, ignition, accessory wake up serial data 2, and serial data circuit terminals.

  1. Vehicle OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. Disconnect the X1 harness connector at the T6 Power Inverter Module. It may take up to 2 min for all vehicle systems to power down.
  2. Test for less than 10 Ω between the ground circuit terminal (or T6 Power Inverter Module case) and ground.
    • If 10 Ω or greater 

      Check the ground connection and ground strap for the open/high resistance.

    • If less than 10 Ω 
  3. Vehicle in Service Mode.
  4. If equipped, verify a test lamp illuminates between each B+ circuit terminal and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Vehicle OFF.
    2. Test for less than 2 Ω in the B+ circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is not open and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Vehicle OFF.
    2. Test for infinite resistance between the B+ circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the T6 Power Inverter Module.
    • If the test lamp illuminates 
  5. If equipped, verify a test lamp illuminates between each ignition circuit terminal and ground.
    • If the test lamp does not illuminate and the circuit fuse is good 
    1. Vehicle OFF.
    2. Test for less than 2 Ω in the ignition circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, verify the fuse is OK and there is voltage at the fuse.
    • If the test lamp does not illuminate and the circuit fuse is open 
    1. Vehicle OFF.
    2. Test for infinite resistance between the ignition circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance, replace the T6 Power Inverter Module.
    • If the test lamp illuminates 
  6. If equipped, verify a test lamp illuminates between the accessory wakeup serial data 2 circuit terminal and ground.
    • If the test lamp does not illuminate 
    1. Vehicle OFF, disconnect the harness connectors at the K114B Hybrid/EV Powertrain Control Module 2.
    2. Test for infinite resistance between the accessory wakeup serial data 2 circuit and ground.
      • If less than infinite resistance, repair the short to ground on the circuit.
      • If infinite resistance
    3. Test for less than 2 Ω in the accessory wakeup serial data 2 circuit end to end.
      • If 2 Ω or greater, repair the open/high resistance in the circuit.
      • If less than 2 Ω, replace the K114B Hybrid/EV Powertrain Control Module 2.
    • If the test lamp illuminates 
  7. Vehicle OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. Disconnect the X357 and X358 harness connectors at the A4 Hybrid/EV Battery Pack. It may take up to 2 min for all vehicle systems to power down.
  8. Test for less than 2 Ω in each high speed GMLAN serial data circuits end to end between the T6 Power Inverter Module and the A4 Hybrid/EV Battery Pack.
    • If 2 Ω or greater 

      Repair the open/high resistance in the serial data circuit.

    • If less than 2 Ω 
  9. Vehicle OFF, disable the high voltage system. Refer to High Voltage Disabling .
  10. Reconnect the 12 V battery.
  11. Vehicle OFF, all access doors closed, all vehicle systems OFF, and all keys at least 3 m (9.8 ft) away from vehicle. Disconnect the X8 harness connector at the K16 Battery Energy Control Module. It may take up to 2 min for all vehicle systems to power down.
  12. Test for less than 2 Ω in each high speed GMLAN serial data circuits end to end between the A4 Hybrid/EV Battery Pack and the K16 Battery Energy Control Module.
    • If 2 Ω or greater 

      Repair the open/high resistance in the serial data circuit.

    • If less than 2 Ω 
  13. Replace the T6 Power Inverter Module.
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