P0CBF
DTC P0CBD-P0CBF
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 Descriptors
DTC P0CBD
- Drive Motor "A" Coolant Temperature Sensor Performance
DTC P0CBE
- Drive Motor "A" Coolant Temperature Sensor Circuit Low
DTC P0CBF
- Drive Motor "A" Coolant Temperature Sensor Circuit High
Circuit/System Description
The hybrid electronics coolant temperature sensor is a variable resistor that measures the temperature of the starter/generator coolant. The starter/generator control module supplies 5 V to the signal circuit and a ground for the low reference circuit. The hybrid electronics coolant temperature sensor resistance changes with starter/generator coolant temperature. As the temperature decreases, the sensor resistance increases. As the temperature increases, the sensor resistance decreases. The starter/generator control module monitors the hybrid electronics coolant temperature sensor to determine the temperature of the starter/generator coolant. As the coolant temperature changes, the starter/generator control module will turn the starter/generator control module coolant pump ON or OFF to accommodate the starter/generator cooling requirements.
The starter/generator control module performs a rationality diagnostic that compares the hybrid electronics coolant temperature sensor signal to the average temperature of the starter/generator stator, engine intake air temperature, and transmission fluid temperature. This diagnostic gets one chance to run during a drive cycle after a specific vehicle OFF time.
Conditions for Running the DTC
P0CBD
* Ignition is RUN or CRANK
* Engine off time is greater than 6 hours
* starter/generator control module internal clock diagnostic is not faulted
* None of the following DTCs are set: P0111, P0112, P0113, P0114, P0711, P0712, P0713, P0A2B, P0A2C, P0A2D, P0CBF, POCBE, P0CBD, U0100, U0101, P2610
P0CBE or P0CBF
* Ignition is RUN or CRANK
* Starter/generator control module internal coolant temperature monitoring and diagnostics are enabled
Conditions for Setting the DTC
P0CBD
The hybrid electronics coolant temperature sensor is more than 25°C (45°F) higher or lower than the average temperature of the starter/generator stator, engine intake air temperature, and transmission fluid temperature.
P0CBE
The drive motor coolant temperature sensor resistance is less than 100.7 ohm.
P0CBF
The drive motor coolant temperature sensor resistance is greater than 176,962 ohm.
Action Taken When the DTC Sets
DTC P0CBD-P0CBF are type B DTCs
Conditions for Clearing the DTC
DTC P0CBD-P0CBF are type B DTCs
Reference Information
Schematic Reference
Hybrid Cooling Schematics Hybrid Cooling Schematics
Connector End View Reference
Component Connector End Views Connector End Views By Name
Description and Operation
Hybrid Cooling System Description and Operation Hybrid Cooling System Description and Operation
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
1. Verify the coolant level of the starter/generator cooling system is normal.
• If the coolant level is low, inspect the starter/generator cooling system for any leaks.
2. Verify the starter/generator cooling system auxiliary radiator is clear of any debris, bent fins, or other damage which may inhibit airflow.
• If debris are found, clean the auxiliary radiator. If damage is found, replace the auxiliary radiator.
3. Verify the starter/generator cooling system hoses are properly routed and are not kinked.
• If any hoses are misrouted or kinked, removed and properly reroute the hose.
4. Ignition ON, observe the scan tool Motor A Coolant Temperature Sensor parameter. The reading should be between -40°C and 85°C.
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 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.
1. Ignition OFF, disconnect the harness connector at the B202 hybrid electronics coolant temperature sensor.
2. Test for less than 10 ohm between the low reference circuit terminal B and ground.
• If greater than the specified range, test the low reference circuit for an open/high resistance. If the circuit tests normal, replace the K59 starter/generator control module.
3. Ignition ON, verify the scan tool Motor A Coolant Temperature Sensor parameter is less than -38°C.
• If greater than the specified range, test the signal circuit terminal A for a short to ground. If the circuit tests normal, replace the K59 starter/generator control module.
4. Install a 3 A fused jumper wire between the signal circuit terminal A and the low reference circuit terminal B. Verify the scan tool Motor A Coolant Temperature Sensor parameter is greater than 80°C.
• If less than the specified range, test the signal circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K59 starter/generator control module.
5. If all circuits test normal, replace the B202 hybrid electronics coolant temperature sensor.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Auxiliary Radiator Replacement Auxiliary Radiator Replacement
* Control Module References Control Module References for starter/generator control module replacement, setup, and programming