P1B3E
DTC P1B3E
Diagnostic Instructions
Danger: This diagnostic has NOT been validated on-vehicle. Follow all safety protocol and utilize all appropriate personal protective equipment to ensure your safety. Failure to follow the procedures exactly as written may result in serious injury or death.
* 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 Descriptor
DTC P1B3E
- Hybrid Battery Voltage Sense Low Reference 2 Circuit
Circuit/System Description
The hybrid battery pack contains a total of 32 cell groups in the hybrid/EV battery pack assembly. These cell groups are electrically connected in series. Each individual cell group is rated at 3.7 V, for a nominal system voltage of 118 V DC. The battery cells are grouped together into two sections, each with 16 cell groups.
The battery energy control module monitors the voltage of the 32 battery cell groups. A voltage sense circuit is attached to each individual cell group. Each of these circuits terminate at a connector located on the top surface of the battery section. A serviceable auxiliary battery wiring harness connectors the voltage sense circuits to the battery energy control module, located directly above the hybrid battery pack.
Diagnostics and system status are communicated from the battery energy control module to hybrid powertrain control module through serial data.
Conditions for Running the DTC
* 12 V battery voltage is greater than 8.8 V
* None of the following DTCs are running: P1EAA, P1EAC
* None of the following DTCs are set: P1B34, P1B35, P1B36, P1B37, P1B38, P1B39
Conditions for Setting the DTC
Cell sense voltage is less than 1.4 V
AND
Battery 32 cell voltage change is greater than 0.5 V over a 200ms sample time
Action Taken When the DTC Sets
* DTC P1B3E is a type B DTC
* The vehicle operates in a low battery mode with the high voltage contactors closed, but no hybrid functions will occur
Conditions for Clearing the DTC
DTC P1B3E is a type B DTC
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
Ignition ON, observe the scan tool Hybrid Battery Cell Voltage 32 parameters. Each parameter should be between 3.0-4.1 V and the parameters should be within 0.1 V of each other.
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.
1. Ignition OFF, disable high voltage at the A4 hybrid battery pack. Refer to High Voltage Disabling High Voltage Disabling.
2. Disconnect the K16 battery energy control module X1 and X2 harness connectors.
3. Connect the EL-48571-30 - high voltage battery pin out box to the K16 battery energy control module X2 harness connector.
4. Insert the DMM probes into the EL-48571-30 test cavities.
5. Measure and record the voltage of Cell 32 by selecting the A1 switch setting on the EL-48571-30.
6. Verify that the cell 32 voltage reading is 3.0-4.1 V.
• If not within the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the C4A hybrid/EV battery section 1 and C4B hybrid/EV battery section 2.
7. If all circuits test normal, replace the K16 battery energy control module.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Generator Battery Replacement Generator Battery Replacement
* Control Module References Control Module References for battery energy control module replacement, programming and setup