P0AFB
DTC P0AFA or P0AFB
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 P0AFA
- Hybrid/EV Battery System Voltage Low
DTC P0AFB
- Hybrid/EV Battery System Voltage High
Circuit/System Description
The battery energy control module will diagnose its own systems and determine when a fault condition is present. Diagnostics and system status is communicated from the battery energy control module to the hybrid powertrain control module 2 through serial data. The hybrid powertrain control module 2 is the host controller for diagnostic trouble code (DTC) information. The battery energy control module monitors the hybrid/EV battery voltage at the battery side of the high voltage main contactors.
Conditions for Running the DTC
* The battery energy control module is awake and communicating.
* The system voltage is 9 V.
* None of the following DTCs are set; P0ABC, P0ABD, P1A07, P0AF8, P0ABB, P0B3D, P0B42, P0B47, P0B4C, P0B51, P0B56, P0B5B, P0B60, P0B65, P0B6A, P0B6F, P0B74, P0B79, P0B7E, P0B83, P0B88, P0B8D, P0B92, P0B97, P0B9C, P0BA1, P0BA6, P0BAB, P0BB0, P0BB5, P0BBA, P1B17, P1B1A, P1B1D, P1B20, P1B23, P1B26, P1B46, P1B49, P1B4C, P1B4F, P1B52, P1B55, P1B58, P1B5B, P1B5E, P1B61, P1B64, P1B67, P1B6A, P1B6D, P1B70, P1B73, P1B76, P1B79, P1B7C, P1B7F, P1B82, P1B85, P1B88, P1B8B, P1B8E, P1B91, P1B94, P1B97, P1B9A, P1B9D, P1BA0, P1BA3, P1BA6, P1BA9, P1BAC, P1BAF, P1BB2, P1BB5, P1BB8, P1BBB, P1BBE, P1BC1, P1BC4, P1BC7, P1BCA, P1BCD, P1BD0, P1BD3, P1BD6, P1BD9, P1BDC, P1BDF, P1BE2, P1BE5, P1BE8, P1BEB, P1BEE, P1BF1, P1BF4, P1BF7, P1BFA, P1BFD, P1E02, P1E05, P0B3E, P0B43, P0B48, P0B4D, P0B52, P0B57, P0B5C, P0B61, P0B66, P0B6B, P0B70, P0B75, P0B7A, P0B7F, P0B84, P0B89, P0B8E, P0B93, P0B98, P0B9D, P0BA2, P0BA7, P0BAC, P0BB1, P0BB6, P0BBB, P1B18, P1B1B, P1B1E, P1B21, P1B24, P1B27, P1B47, P1B4A, P1B4D, P1B50, P1B53, P1B56, P1B59, P1B5C, P1B5F, P1B62, P1B65, P1B68, P1B6B, P1B6E, P1B71, P1B74, P1B77, P1B7A, P1B7D, P1B80, P1B83, P1B86, P1B89, P1B8C, P1B8F, P1B92, P1B95, P1B98, P1B9B, P1B9E, P1BA1, P1BA4, P1BA7, P1BAA, P1BAD, P1BB0, P1BB3, P1BB6, P1BB9, P1BBC, P1BBF, P1BC2, P1BC5, P1BC8, P1BCB, P1BCE, P1BD1, P1BD4, P1BD7, P1BDA, P1BDD, P1BE0, P1BE3, P1BE6, P1BE9, P1BEC, P1BEF, P1BF2, P1BF5, P1BF8, P1BFB, P1BFE, P1E03, P1E06, P1E90, P1E8F, P1E91, P1E8E, P1E93, P1E96, P1E95, P1E97, P1E94, P1E99, P1E9C, P1E9B, P1E9D, P1E9A, P1E9F, P1EA2, P1EA1, P1EA3, P1EA0, P1EA5, P1EB1, P1EB5, P0B3B, P0B40, P0B45, P0B4A, P0B4F, P0B54, P0B59, P0B5E, P0B63, P0B68, P0B6D, P0B77, P0B7C, P0B81, P0B86, P0B8B, P0B95, P0B9A, P0B9F, P0BA4, P0BA9, P0BAE, P0BB3, P0BB8, P1B28, P1B29, P1B2A, P1B2B, P1B2C, P1B2D, P1E4C, P1E4D, P1E4E, P1E4F, P1E50, P1E51, P1E52, P1E53, P1E54, P1E56, P1E57, P1E58, P1E59, P1E5A, P1E5B, P1E5C, P1E5D, P1E5E, P1E5F, P1E60, P1E61, P1E62, P1E63, P1E64, P1E65, P1E66, P1E67, P1E68, P1E69, P1E6A, P1E6B, P1E6C, P1E6E, P1E6F, P1E70, P1E71, P1E72, P1E73, P1E74, P1E75, P1E76, P1E77, P1E78, P1E79, P1E7A, P1E7B, P1E7C, P1E7D, P1E7E, P1E7F, P1E80, P1E81, P1E82, P1E83, P1E84, P1E86, P1E87, P1E88, P1E89, P1E8A, P0B3C, P0B41, P0B46, P0B4B, P0B50, P0B55, P0B5A, P0B5F, P0B64, P0B69, P0B6E, P0B73, P0B78, P0B7D, P0B82, P0B87, P0B8C, P0B91, P0B96, P0B9B, P0BA0, P0BA5, P0BAA, P0BAF, P0BB4, P0BB9, P1B16, P1B19, P1B1C, P1B1F, P1B22, P1B25, P1B45, P1B48, P1B4B, P1B4E, P1B51, P1B54, P1B57, P1B5A, P1B5D, P1B60, P1B63, P1B66, P1B69, P1B6C, P1B6F, P1B72, P1B75, P1B78, P1B7B, P1B7E, P1B81, P1B84, P1B87, P1B8A, P1B8D, P1B90, P1B93, P1B96, P1B99, P1B9C, P1B9F, P1BA2, P1BA5, P1BA8, P1BAB, P1BAE, P1BB1, P1BB4, P1BB7, P1BBA, P1BBD, P1BC0, P1BC3, P1BC6, P1BC9, P1BCC, P1BCF, P1BD2, P1BD5, P1BD8, P1BDB, P1BDE, P1BE1, P1BE4, P1BE7, P1BEA, P1BED, P1BF0, P1BF3, P1BF6, P1BF9, P1BFC, P1E01, P1E04
Conditions for Setting the DTC
P0AFA
The Hybrid Battery Pack Voltage is less than 205 V.
OR
The Minimum Hybrid Battery Cell Group Voltage in the hybrid battery is less than 2.05 V.
P0AFB
The Hybrid Battery Pack Voltage is greater than 419 V.
OR
The Maximum Hybrid Battery Cell Group Voltage in the hybrid battery is greater than 4.4 V.
Action Taken When the DTC Sets
* DTCs P0AFA and P0AFB are type A DTCs.
* If any of these DTCs are set, the vehicle will operate in a reduced power mode and charge sustaining mode.
* Once ignition has been turned OFF the contactors will be prevented from closing.
Conditions for Clearing the DTC
P0AFA and P0AFB
* DTCs P0AFA and P0AFB are type A DTCs.
* The Clear Secured High Voltage DTCs Reading and Clearing Diagnostic Trouble Codes reset function must be performed with a scan tool before clear codes.
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-48571-25 - High Voltage Battery Pin Out Box
* EL-48900 - HEV Safety Kit
For equivalent regional tools, refer to Special Tools Tools and Equipment.
Circuit/System Verification
1. Verify that DTC P0AA1, P0AD9, P0ADD, P0AE2, P0AE4, P0B3B, P0B3C, P0B3D, P0B3E, P0B40, P0B41, P0B42, P0B43, P0B45, P0B46, P0B47, P0B48, P0B4A, P0B4B, P0B4D, P0B4C, P0B4F, P0B50, P0B51, P0B52, P0B54, P0B55, P0B56, P0B57, P0B59, P0B5A, P0B5B, P0B5C, P0B5E, P0B60, P0B5F, P0B61, P0B63, P0B64, P0B65, P0B66, P0B69, P0B68, P0B6A, P0B6D, P0B6B, P0B6E, P0B70, P0B6F, P0B72, P0B74, P0B73, P0B75, P0B77, P0B78, P0B79, P0B7A, P0B7D, P0B7C, P0B7E, P0B7F, P0B81, P0B82, P0B83, P0B84, P0B86, P0B87, P0B88, P0B89, P0B8B, P0B8C, P0B8D, P0B8E, P0B90, P0B91, P0B92, P0B93, P0B95, P0B96, P0B97, P0B98, P0B9A, P0B9B, P0B9C, P0B9D, P0B9F, P0BA1, P0BA0, P0BA2, P0BA4, P0BA5, P0BA6, P0BA7, P0BA9, P0BAA, P0BAB, P0BAC, P0BAE, P0BAF, P0BB0 ,P0BB1, P0BB3, P0BB4, P0BB5, P0BB6, P0BB8, P0BB9, P0BBA, P0BBB, P0D0A, P0D11, P1B16, P1B17, P1B18, P1B19, P1B1A, P1B1B, P1B1C, P1B1D, P1B1E, P1B1F, P1B20, P1B21, P1B22, P1B23, P1B24, P1B25, P1B26, P1B27, P1B28, P1B29, P1B2B, P1B2A, P1B2C, P1B2D, P1B45, P1B46, P1B47, P1B48, P1B49, P1B4A, P1B4B, P1B4C, P1B4D, P1B4E, P1B4F, P1B50, P1B51, P1B52, P1B53, P1B54, P1B55, P1B56, P1B57, P1B58, P1B59, P1B5A, P1B5B, P1B5C, P1B5D, P1B5E, P1B5F, P1B60 ,P1B61 ,P1B62, P1B63, P1B64, P1B65, P1B66, P1B67, P1B68, P1B69, P1B6A, P1B6B, P1B6C, P1B6D, P1B6E, P1B6F, P1B70, P1B71, P1B72, P1B73, P1B74, P1B75, P1B76, P1B77, P1B78, P1B79, P1B7A, P1B7B, P1B7C, P1B7D, P1B7F, P1B7E, P1B80, P1B81, P1B82, P1B83, P1B84, P1B85, P1B86, P1B87, P1B88, P1B89, P1B8A, P1B8B, P1B8C, P1B8D, P1B8E, P1B8F, P1B90, P1B91, P1B92, P1B93, P1B94, P1B95, P1B97, P1B96, P1B98, P1B99, P1B9A, P1B9B, P1B9C, P1B9D, P1B9E, P1B9F, P1BA0, P1BA1, P1BA2, P1BA3, P1BA4, P1BA5, P1BA6, P1BA7, P1BA8, P1BA9 ,P1BAB, P1BAA, P1BAC, P1BAD, P1BAE, P1BAF, P1BB0, P1BB1, P1BB2, P1BB3, P1BB4, P1BB5, P1BB6, P1BB7, P1BB8, P1BB9, P1BBA, P1BBB, P1BBC, P1BBD, P1BBE, P1BBF, P1BC0, P1BC1, P1BC2, P1BC3, P1BC4, P1BC5, P1BC6, P1BC7, P1BC8, P1BC9, P1BCA, P1BCB, P1BCC, P1BCE, P1BCD, P1BCF, P1BD0, P1BD2, P1BD1, P1BD3, P1BD4, P1BD5, P1BD6, P1BD7, P1BD8, P1BD9, P1BDA, P1BDB, P1BDD, P1BDC, P1BDE, P1BDF, P1BE1, P1BE0, P1BE3, P1BE2, P1BE4, P1BE5, P1BE6, P1BE7, P1BE8, P1BE9, P1BEA, P1BEB, P1BEC, P1BED, P1BEE, P1BF0, P1BEF, P1BF1, P1BF2, P1BF4, P1BF3, P1BF5, P1BF4, P1BF7, P1BF8, P1BF9, P1BFA, P1BFB, P1BFC, P1BFD, P1BFE, P1E01, P1E02, P1E03, P1E04, P1E05, P1E06, P1E4C, P1E4D, P1E4E, P1E4F, P1E50, P1E51, P1E52, P1E53, P1E54, P1E55, P1E56, P1E57, P1E58, P1E59, P1E5A, P1E5B, P1E5C, P1E5D, P1E5E, P1E5F, P1E60, P1E62, P1E61, P1E63, P1E64, P1E65, P1E66, P1E67, P1E68, P1E69, P1E6A, P1E6B, P1E6D, P1E6C, P1E6E, P1E6F, P1E70, P1E71, P1E72, P1E73, P1E74, P1E76, P1E75, P1E77, P1E78, P1E79, P1E7A, P1E7B, P1E7C, P1E7D, P1E7E, P1E7F, P1E80, P1E81, P1E82, P1E83, P1E84, P1E85, P1E86, P1E87, P1E88, P1E89, P1E8A, P1EBC, P1EBD, P1EBF, P1EC0, P1EC3, P1EC4, P1EC5, U2603, U2604, U2605, U2606, or U2401 is not set.
• If any of the DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. Vehicle in Service Mode, engine OFF, verify the scan tool Hybrid Battery Pack Terminal 1 Voltage parameter is between 205-419 V.
• If the Hybrid Battery Pack Terminal 1 Voltage parameter is not within the specified range, refer to Hybrid Battery Pack Voltage Diagnosis.
3. Observe the scan tool Hybrid Battery 1-96 voltage parameters. Each reading should be between 3.0-4.1 V and all readings should be within 0.1 V of each other.
• If the Hybrid Battery 1-96 cell group voltages are not within the specified range, refer to Hybrid Battery 1-96 Cell Group Diagnosis.
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.
Hybrid Battery Pack Voltage Diagnosis
1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling High Voltage Disabling.
2. Install the S15 hybrid/EV battery pack high voltage manual disconnect lever.
3. Test for 205-419 V between the KR34A Hybrid/EV Battery Negative Contactor and the KR34B Hybrid/EV Battery Positive Contactor.
• If not within the specified range, replace the A4 hybrid/EV battery pack.
4. Disconnect X3 harness connector at the K16 battery energy control module.
5. Test for less than 10 ohm between the terminals listed below of the A28 hybrid battery contactor assembly.
* KR34A Hybrid/EV Battery Negative Contactor and the K16 battery energy control module terminal 4 X3
* KR34B Hybrid/EV Battery Positive Contactor and the K16 battery energy control module terminal 1 X3
• If greater than the specified value, replace the A28 hybrid battery contactor assembly. After the repair is complete with a scan tool, the Clear Secured High Voltage DTCs Reading and Clearing Diagnostic Trouble Codes reset function must be performed.
6. If all circuits test normal, replace the K16 battery energy control module.
Hybrid Battery 1-96 Cell Group Diagnosis
Note: Use the schematics to identify the correct drive motor battery interface control module and battery section.
1. Vehicle OFF, disable the high voltage at the A4 hybrid/EV battery pack. Refer to High Voltage Disabling High Voltage Disabling.
2. Disconnect the appropriate drive motor battery interface control module harness connector.
3. Connect the EL-48571-25 - high voltage battery pin out box.
4. Insert the DMM probes into the EL-48571-25 test cavities.
Note:
* The DMM must be set to the DC voltage setting.
* Depending on the cell group not all 22 switch positions of the EL-48571-25 will be used.
* If working with battery section 2 the high voltage manual disconnect will need to be installed to insure proper cell group readings.
5. Measure and record the voltage of each of the cell groups of the appropriate hybrid battery section by cycling the EL-48571-25 through each of the 22 switch positions.
6. Each cell group voltage reading should be between 3.0-4.1 V.
• If not within the specified range, test the circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the A4 hybrid battery pack. After the repair is complete with a scan tool, the Clear Secured High Voltage DTCs Reading and Clearing Diagnostic Trouble Codes reset function must be performed.
7. Each cell group voltage reading should be within 0.1 V of each other.
• If not within the specified range, test the circuit for an open/high resistance. If the circuit tests normal, replace the A4 hybrid battery pack. After the repair is complete with a scan tool, the Clear Secured High Voltage DTCs reset function must be performed.
8. If all circuits test normal, replace the appropriate hybrid battery interface control module. After the repair is complete with a scan tool, the Clear Secured High Voltage DTCs Reading and Clearing Diagnostic Trouble Codes reset function must be performed.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Drive Motor Battery Wire Junction Block Relay Replacement Drive Motor Battery Wire Junction Block Relay Replacement
* Drive Motor Battery Replacement and Shipping Preparation Procedures
* Control Module References Programming and Relearning for battery energy control module and hybrid interface control battery module 1-4 replacement, programming and setup