P0A0C
DTC P0A0C or P0A0D
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.
DTC Descriptors
DTC P0A0C
- High Voltage System Interlock Circuit Low Voltage
DTC P0A0D
- High Voltage System Interlock Circuit High Voltage
Circuit/System Description
The main high voltage interlock circuit is utilized to verify high voltage component integrity. The main high voltage interlock circuit is used to determine if access to high voltage components is being attempted. The opening of these high voltage components causes the main high voltage interlock circuit to open. The hybrid powertrain control module 2 sources about 12 mA of current on the 5 V main high voltage interlock circuit loop. The hybrid powertrain control module 2 monitors both the main high voltage interlock 5 V reference circuit current and the main high voltage interlock signal circuit current in order to detect circuit faults. When the hybrid powertrain control module 2 detects a loss of main high voltage interlock circuit current, the high voltage contactors are commanded open.
Conditions for Running the DTC
P0A0C
* The 12 V battery voltage is greater than 9 V.
* The high voltage contactors are closed.
P0A0D
* The 12 V battery voltage is greater than 9 V.
* The hybrid powertrain control module 2 is awake and communicating.
Conditions for Setting the DTC
P0A0C
* The hybrid powertrain control module 2 detects main high voltage interlock circuit 5 V reference current is between 5-18 mA and high voltage interlock circuit signal current is less than 5 mA.
* DTC P0A0C sets within 1 second when the above condition is met.
P0A0D
* The hybrid powertrain control module 2 detects main high voltage interlock circuit 5 V reference current is less than 5 mA and high voltage interlock circuit signal current is greater than 35 mA.
* DTC P0A0D sets within 1 second when the above condition is met.
Action Taken When the DTC Sets
* DTCs P0A0C and P0A0D are Type A DTCs.
* The hybrid powertrain control module 2 opens the main high voltage contactors when vehicle speed is less than 5 km/h (3 mph).
Conditions for Clearing the DTC
DTCs P0A0C and P0A0D are Type A DTCs.
Diagnostic Aids
* Test for a fully engaged hybrid battery pack high voltage manual disconnect whenever an open high voltage interlock circuit condition is observed. The hybrid battery pack high voltage manual disconnect must be pressed down fully in order to engage the high voltage interlock circuit terminals.
* The main high voltage interlock circuit is also routed through several inline connectors.
* With the ignition in the OFF position, the hybrid powertrain control module 2 will source 12 mA on the main high voltage interlock circuit for 5 minutes every time a vehicle door is opened.
Note: The following diagnostic aid applies for both current and history DTCs.
* Tapping or wiggling the F115 Hybrid/EV Battery Pack Fuse Cover may duplicate the condition.
Reference Information
Schematic Reference
Hybrid Energy Storage Schematics Hybrid Energy Storage Schematics
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
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 Programming and Relearning 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
Vehicle in Service Mode, observe the hybrid powertrain control module 2 High Voltage Interlock Circuit Status parameter.
The parameter should indicate a PASS condition.
Circuit/System Testing
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 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.
Note: The charger high voltage interlock circuit is routed through several inline connectors.
1. Vehicle OFF, disable high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling High Voltage Disabling.
2. Connect the 12 V battery.
3. Vehicle in Service Mode, test for 4.8-5.2 V between the 5 V reference circuit terminal A 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 K114B hybrid powertrain control module 2.
• If greater than the specified range, test the 5 V reference circuit for a short to voltage. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.
4. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for 8-10k ohm between the signal circuit terminal B and ground.
• If less than the specified range, test the signal circuit for a short to ground. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.
• If greater than the specified range, test the signal circuit for an open/high resistance. If the circuit tests normal, replace the K114B hybrid powertrain control module 2.
5. If all circuits test normal, test or replace the S15 hybrid battery pack high voltage manual disconnect.
Component Testing
Test for 35-45 ohm between the following terminals of the S15 hybrid battery pack high voltage manual disconnect:
* Terminal A and terminal B
* Terminal C and terminal D
If not within the specified range, replace the S15 hybrid battery pack high voltage manual disconnect.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Control Module References Programming and Relearning for hybrid powertrain control module 2, 14 V power module, power inverter module, air conditioning compressor control module, and coolant heater control module replacement, programming and setup