Loss of Isolation on the High Voltage Main Bus
Loss of Isolation on the High Voltage Main Bus
Danger: Ensure all High Voltage safety procedures are followed. Failure to follow the procedure exactly as written may result in serious injury or death.
Danger: 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 procedure exactly as written may result in serious injury or death.
Danger: This vehicle is equipped with a high voltage battery that is completely isolated from the chassis ground. Never utilize AC powered test equipment to probe the high voltage system. Serious injury, death and component damage could occur if the high voltage system is grounded through the electric utility.
Failure to follow the procedure exactly as written may result in serious injury or death.
Danger: 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.
Special Tools
EL-48900 - HEV Safety Kit
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Loss of Isolation on the High Voltage Main Bus
Note: Wear your High Voltage Insulation gloves until you have determined that a high voltage exposure risk is no longer present.
1. Vehicle OFF, disable the high voltage at the A4 hybrid battery pack. Refer to High Voltage Disabling High Voltage Disabling.
2. Connect the 12 V battery.
3. Vehicle in Service Mode, verify that DTC P0AA1, P0AD9, P0ADD, P0AE2, P0AE4, P0D0A, P0D11, P1EBC-P1EBF, P1EC0, or P1EC3-P1EC5 is not set.
• If any DTC is set, diagnose them first. Refer to DTC P0AA1, P0AD9, P0ADD, P0AE2, P0AE4, P0D0A, P0D11, P1EBC-P1EBF, P1EC0, or P1EC3-P1EC5 P0AA1.
4. Vehicle OFF, disconnect the 12 V battery. Refer to Battery Negative Cable Disconnection and Connection Battery Negative Cable Disconnection and Connection.
Note: The following continuity tests must be performed using an Insulation Multimeter. Select the Isolation test setting, then select the 500 V range.
5. Using the Insulation Multimeter, test for greater than 750k ohm between the circuit terminals listed below and ground.
* A28 Hybrid battery contactor assembly harness connector terminal A +300 V X4.
* A28 Hybrid battery contactor assembly harness connector terminal B -300 V X4.
• If the test result is less than the specified value, disconnect the X356A connector at the K1 14 V power module. Test for greater than 750k ohm. If the test result is greater than the specified value, replace the K1 14 V power module. If the test result is less than the specified value, replace the 300 V DC cables.
6. Test for greater than 750k ohm between the circuit terminals listed below and ground.
* T6 Power inverter module harness connector terminal A -300 V X3.
* T6 Power inverter module harness connector terminal B +300 V X3.
• If the test result is less than the specified value, replace the 300 V DC cables.
7. Disconnect the X4 harness connector at the T6 power inverter module.
Note: The following continuity tests require both the air conditioning control module and cabin heater control module circuits to be isolated by performing the following test up to 3 times if a fault is detected.
8. Test for greater than 750k ohm between the circuit terminals listed below and ground.
* Terminal A +300 V X4.
* Terminal B -300 V X4.
• If the test result is less than the specified value, disconnect the X2 connector at the G1 air conditioning control module. Test for greater than 750k ohm between the circuit terminal and ground. If the test result is greater than the specified value, replace the G1 air conditioning control module.
• If the test result is less than the specified value, with the X2 connector at the G1 air conditioning control module disconnected. Disconnect the X2 connector at the K10 cabin heater control module. Test for greater than 750k ohm between the circuit terminal and ground. If the test result is greater than the specified value, replace the K10 cabin heater control module. If the test result is less than the specified value, replace the 300 V DC cables.
9. Disconnect the X5 harness connector at the at the T6 power inverter module
Note: There may be up to a 5 second delay for proper test results to be displayed.
10. Test for greater than 750k ohm between the 3 phase cable circuit terminals listed below and ground.
* Terminal 1 300 V X5.
* Terminal 2 300 V X5.
* Terminal 3 300 V X5.
• If the test result is less than the specified value, disconnect the X2 connector at the M15A Drive Motor 1. Test for greater than 750k ohm between the circuit terminal X2 at the M15A Drive Motor 1 and ground. If the test result is greater than the specified value, replace the 3 phase cables. If the test result is less than the specified value, replace the M15A Drive Motor 1.
11. Disconnect the X6 harness connector at the at the T6 power inverter module.
12. Test for greater than 750k ohm between the 3 phase cable circuit terminals listed below and ground.
* Terminal 1 300 V X6.
* Terminal 2 300 V X6.
* Terminal 3 300 V X6.
• If the test result is less than the specified value, disconnect the X2 connector at the M15A Drive Motor 1. Test for greater than 750k ohm between the circuit terminal X2 at the M15B Drive Motor 2 and ground. If the test result is greater than the specified value, replace the 3 phase cables. If the test result is less than the specified value, replace the M15B Drive Motor 2.
13. Disconnect the X8 harness connector at the at the power inverter module.
14. Test for greater than 1.0M ohm between the 3 phase cable circuit terminals listed below and ground.
* Terminal 1 300 V X8.
* Terminal 2 300 V X8.
* Terminal 3 300 V X8.
• If the test result is less than the specified value, replace the G5 transmission fluid pump - auxiliary.
15. Test for greater than 750k ohm between the T6 power inverter module circuit terminals listed below and ground.
* Terminal A +300 V X3.
* Terminal B -300 V X3.
* Terminal A +300 V X4.
* Terminal B -300 V X4.
* Terminal 1 300 V X5.
* Terminal 2 300 V X5.
* Terminal 3 300 V X5.
* Terminal 1 300 V X6.
* Terminal 2 300 V X6.
* Terminal 3 300 V X6.
* Terminal 1 300 V X8.
* Terminal 2 300 V X8.
* Terminal 3 300 V X8.
• If the test result is less than the specified value, replace the T6 power inverter module.
16. If all circuits test normal, replace the A4 hybrid battery pack.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
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* Control Module References Programming and Relearning for the T6 power inverter module replacement, programming and setup