Circuit/System Testing
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.
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.
- Ignition OFF, disable high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling
- Disconnect the U, V, and W three phase lugs at the K59 starter/generator control module.
- Test for greater than 400K Ω between the terminals listed below and chassis ground with the EL-50772
Insulation Multimeter set on the Isolation test setting:
- 3 phase cable terminal U - cable side lug
- 3 phase cable terminal V - cable side lug
- 3 phase cable terminal W - cable side lug
- If 400K Ω or less
- Disconnect the U, V, and W three phase lugs at the A15 starter/generator.
- Test for greater than U, V, and W three phase studs at the A15 starter/generator and chassis ground with the EL-50772
Insulation Multimeter set on the Isolation test setting.
- If 400K Ω or less, replace the A15 starter/generator.
- If greater than 400K Ω
- Replace the high voltage 3 phase cables.
- If greater than 400K Ω
- Test for greater than 400K Ω between the terminals listed below and chassis ground with the EL-50772
Insulation Multimeter set on the Isolation test setting:
- 3 phase terminal U - K59 starter/generator control module stud
- 3 phase terminal V - K59 starter/generator control module stud
- 3 phase terminal W - K59 starter/generator control module stud
- If 400K Ω or less
- Disconnect and remove the two wiring junction blocks from the A4 hybrid/EV battery pack.
- Test for greater than U, V, and W three phase studs at the K59 starter/generator control module and chassis ground with the EL-50772
Insulation Multimeter set on the Isolation test setting.
- If 400K Ω or less, replace the K59 starter/generator control module.
- If greater than 400K Ω
- Replace the two wiring junction blocks.
- If greater than 400K Ω
- Replace the C4A hybrid/EV battery section 1 and C4B hybrid/EV battery section 2.
The following continuity tests must be performed using the EL-50772 Insulation Multimeter. Select the Isolation test setting, then select the 500 V range.
The following continuity tests must be performed using the EL-50772 Insulation Multimeter. Select the Isolation test setting, then select the 500 V range.