Hybrid/EV Battery Voltage Present
Hybrid\EV Battery Voltage Present
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Circuit/System Description
The vehicle is equipped with a high voltage isolation monitor feature. The purpose of the isolation monitor is to test the resistance between the high voltage positive and negative direct current (DC) bus and chassis ground. The isolation monitoring system measures the resistance between the high voltage system and chassis ground.
Reference Information
Schematic Reference
Hybrid Energy Storage Schematics [1][2]Electrical Diagrams
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Drive Motor Battery System Description Drive Motor Battery System Description
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References Control Module References for scan tool information
Special Tools
EL-48900 - HEV Safety Kit
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
Danger: 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.
Danger: The eAssist battery pack assembly will utilize an exchange program. Please consult the most recent revision of bulletin/PI #PIPXXYYZZ, 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.
Note: In High Voltage Disabling High Voltage Disabling , perform the disabling procedure for servicing components within the A4 hybrid/EV battery pack. The C4A hybrid/EV battery section 1 and C4B hybrid/EV battery section 2 will be disconnected as part of the disabling procedure.
1. Ignition OFF, disable high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling High Voltage Disabling.
2. Test for infinite resistance between the high voltage terminals at the KR39 main contactor.
• If less than the specified range, the KR39 main contactor is stuck closed. Replace the KR39 main contactor.
3. Test for infinite resistance between the high voltage terminals at the KR134 pre-charge contactor.
• If less than the specified range, the KR134 pre-charge contactor is stuck in the closed position. Replace the KR pre-charge contactor.
4. Test for infinite resistance between the high voltage terminals at the S15 hybrid/EV battery pack high voltage manual disconnect lever.
• If less than the specified range, the S15 hybrid/EV battery pack high voltage manual disconnect lever is stuck in the closed position. Replace the S15 hybrid/EV battery pack high voltage manual disconnect lever.
5. If all circuits test normal, replace the K59 starter/generator control module.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Generator Battery Control Wiring Harness Replacement (Generator Battery Discon Relay to B2) Generator Battery Control Wiring Harness Replacement (Generator Battery Discon Relay to B2)Generator Battery Control Wiring Harness Replacement (B1 and B2 to BECM Junction Block) Generator Battery Control Wiring Harness Replacement (B1 and B2 to BECM Junction Block)Generator Battery Control Wiring Harness Replacement (B2 to BDU1 Contactor) Generator Battery Control Wiring Harness Replacement (B2 to BDU1 Contactor)
* Control Module References Control Module References for starter/generator control module replacement, programming, and setup