P0C47
Hybrid/EV Battery Pack Coolant Pump Malfunction - DTC P0C47, P0C4A, or P1F18
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 P0C47
- Hybrid/EV Battery Pack Coolant Pump Control Circuit
DTC P0C4A
- Hybrid/EV Battery Pack Coolant Pump Performance
DTC P1F18
- Hybrid/EV Battery Pack Coolant Pump Enable Circuit
Circuit/System Description
The hybrid/EV battery pack coolant pump circulates coolant through the drive motor battery coolant radiator, drive motor battery coolant cooler, and the hybrid/EV battery pack to control the temperature of the hybrid/EV battery pack. An enable signal from the hybrid/EV powertrain control module 2 to the hybrid/EV battery pack coolant pump provides overall control of the pump. When this circuit is high, the pump can operate. The pump is controlled with a pulse-width modulated signal from the hybrid/EV powertrain control module 2 to the hybrid/EV battery pack coolant pump. The higher the duty cycle the higher the pump speed. The hybrid/EV battery pack coolant pump provides a hard-wired pulse-width modulated feedback signal to the hybrid/EV powertrain control module 2. During normal operation, this feedback signal provides pump speed information to the hybrid/EV powertrain control module 2. The hybrid/EV battery pack coolant pump has some self-diagnostic capability. If the hybrid/EV battery pack coolant pump determines there is an internal fault it provides this information on this same feedback circuit instead of pump speed information.
Conditions for Running the DTC
P0C47
* The 12 V battery voltage is greater than or equal to 9 V.
* The coolant pump enable is commanded.
P0C4A
* The 12 V battery voltage is greater than or equal to 9 V.
* The hybrid/EV powertrain control module 2 is awake and communicating with the battery energy control module.
* Runs once per ignition cycle when the propulsion system goes active.
* The heater performance diagnostic has passed.
* None of the following DTCs are set: P0C44, P0C45, P0C47, P1EC6, P1F18, U0111, U18B, or U2602.
P1F18
The 12 V battery voltage is greater than or equal to 9 V.
Conditions for Setting the DTC
P0C47
The hybrid/EV powertrain control module 2 detects the Coolant Pump Control circuit is open, shorted to voltage or shorted to ground.
P0C4A
The hybrid/EV powertrain control module 2 did not see the battery inlet temperature fall fast enough during the 18 second test period. The hybrid/EV powertrain control module 2 did not detect a decrease of 2° C (3.6° F) in 4 seconds within the 18 second test period.
P1F18
The hybrid/EV powertrain control module 2 detects the Coolant Pump Enable circuit is open, shorted to voltage or shorted to ground.
Action Taken When the DTC Sets
DTCs P0C47, P0C4A, and P1F18 are type B DTCs.
Conditions for Clearing the DTC
DTCs P0C47, P0C4A, and P1F18 are type B DTCs.
Diagnostic Aids
* Low or no coolant in the system may set a DTC P0C4A.
* P1EC5 may cause a DTC P0C4A
* P1F18 may cause a DTC P0C47
Reference Information
Schematic Reference
Hybrid Cooling Schematics Hybrid Cooling Schematics
Connector End View Reference
Component Connector End Views Hybrid/EV Battery Pack X1
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 Programming and Relearning for scan tool information
Circuit/System Verification
1. Verify that DTC P0C43, P0C44, P0C45, P0CE0, P0CE2, P0CE3, P0D0A, P0D11, P1EBC, P1EC3, P1EC4, P1EC5, P1EC6, P1EC7, or P1EC8 is not set.
• If DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle
2. Vehicle in Service Mode, with the pump is disabled and not running, verify the scan tool parameters listed below:
* Hybrid/EV Battery Pack Coolant Pump Command is less than 10%.
* Hybrid/EV Battery Pack Coolant Pump Feedback is 0%.
* Hybrid/EV Battery Pack Coolant Pump Speed is 25 RPM.
3. Vehicle OFF, connect the charge cord set. With the vehicle in Charge Mode, pump enabled and not running, verify the scan tool parameters listed below:
* Hybrid/EV Battery Pack Coolant Pump Command is 10%.
* Hybrid/EV Battery Pack Coolant Pump Feedback to be 50% +/-5%.
* Hybrid/EV Battery Pack Coolant Pump Speed is 50 RPM.
Note: The vehicle must be in Charge Mode and the pump is enabled and not running before proceeding to the next step.
4. Vehicle in Service Mode, command the Hybrid/EV Battery Pack Coolant Pump Heater to 90 kW with a scan tool. Observe the Hybrid/EV Battery Pack Coolant Pump Temperature Sensor 1 parameter. The temperature reading should rise after a 15 second delay, +/- 10 seconds, to above 54° C +/-5° C (129.2° F +/-10°).
5. With the pump enabled and running with the Hybrid/EV Battery Pack Coolant Pump Temperature Sensor 1 parameter above 54° C +/-5° C (129.2° F +/-10°), verify the scan tool parameters listed below:
* Hybrid/EV Battery Pack Coolant Pump Command to be greater than 10%.
* Hybrid/EV Battery Pack Coolant Pump Feedback to be 50% +/-5%.
* Hybrid/EV Battery Pack Coolant Pump Speed is greater than 50 RPM.
6. Verify that the Hybrid/EV Battery Pack Coolant Pump Temperature Sensor 1 parameter dropped to below 40° C (104° F) after a 15 second delay, +/- 10 seconds, with the pump running.
• The Hybrid/EV Battery Pack Coolant Pump Temperature Sensor 1 parameter did not drop to below 40° C (104° F). Refer to Hybrid/EV Battery Cooling Diagnostic Hybrid/EV Battery Cooling Diagnostic
Circuit/System Testing
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. Verify that DTC P0C43, P0C44, P0C45, P1EC5, P1EC6, U0111, U185B, or U2602 is not set.
• If DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. Vehicle OFF, disconnect the harness connector at the G37 hybrid/EV battery pack coolant pump.
3. Vehicle OFF and all vehicle systems OFF. It may take up to 2 minutes for all vehicle systems to power down. Test for less than 5 ohm between the ground circuit terminal 4 and ground.
• If greater than the specified range, test the ground circuit for an open/high resistance.
4. Connect a test lamp between the B+ circuit terminal 5 and ground circuit terminal 4.
5. Vehicle in Service Mode, verify that a test lamp illuminates between the B+ circuit terminal 5 and ground circuit terminal 4.
• If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the B+ circuit fuse is open, test or replace the G37 hybrid/EV battery pack coolant pump.
6. Connect a test lamp between the enable circuit terminal 1 and ground circuit terminal 4.
7. Command the Hybrid Battery Pack Coolant Pump Command OFF (10%) and ON (90%) with a scan tool. Verify the test lamp turns OFF and ON when changing between the commanded states.
• If the test lamp is always illuminated at 10%, test the pump enable circuit for a short to voltage. If the circuit tests normal, replace the K114B hybrid/EV powertrain control module 2.
• If the test lamp does not illuminate at 90%, test the pump enable circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the K114B hybrid/EV powertrain control module 2.
8. Connect a test lamp between the control circuit terminal 3 and the B+ circuit terminal 5.
9. Command the Hybrid Battery Pack Coolant Pump Command ON between 20% and 90% with a scan tool. Verify that a test lamp changes illumination between bright (20%) and dim (90%) between the control circuit terminal 3 and the B+ circuit terminal 5.
• If the test lamp is always dim or does not illuminate, test the control circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K114B hybrid/EV powertrain control module 2.
• If the test lamp is always bright, test the control circuit for a short to ground. If the circuit tests normal, replace the K114B hybrid/EV powertrain control module 2.
10. Verify the scan tool Hybrid/EV Battery Pack Coolant Pump Feedback parameter is less than 10%.
• If greater than the specified range, test the feedback circuit terminal 2 for a short to ground. If the circuit tests normal, replace the K114B hybrid/EV powertrain control module 2.
11. Install a 3 A fused jumper wire between the feedback circuit terminal 2 and the ground circuit terminal 4. Verify the scan tool, Hybrid/EV Battery Pack Coolant Pump Feedback parameter is greater than 90%.
• If less than the specified range, test the feedback circuit for a short to voltage or an open/high resistance. If the circuit tests normal, replace the K114B hybrid/EV powertrain control module 2.
12. If all circuits test normal, replace the G37 hybrid/EV battery pack coolant pump.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
* Drive Motor Battery Coolant Pump Replacement Drive Motor Battery Coolant Pump Replacement
* Control Module References Programming and Relearning for hybrid/EV powertrain control module 2 replacement, programming and setup