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Hybrid/EV Electronics Coolant Pump Malfunction - DTC P0CE9 or P0CED

The hybrid/EV electronics coolant pump circulates coolant through the drive motor battery coolant radiator, hybrid/EV powertrain control module 1 and the battery charger to control the temperature of the hybrid/EV powertrain control module 1 and the battery charger. An enable signal from the hybrid/EV powertrain control module 2 to the hybrid/EV electronics 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 electronics coolant pump. The higher the duty cycle the higher the pump speed. The hybrid/EV electronics 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. The hybrid/EV electronics coolant pump has some self-diagnostic capability. If it determines there is an internal fault, it provides this information on this same feedback circuit instead of pump speed information.

P0CE9

P0CED

P0CE9

The hybrid/EV powertrain control module 2 has detected an open-circuit, short-circuit to voltage or short-circuit to earth on the coolant pump control circuit.

P0CED

The hybrid/EV powertrain control module 2 has detected an open-cicuit, short-circuit to voltage or short-circuit to earth on the coolant pump enable circuit.

DTCs P0CE9 and P0CED are a type B DTCs.

DTCs P0CE9 and P0CED are a type B DTCs.

Schematic Reference

Hybrid Cooling Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Hybrid Cooling System Description and Operation

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Vehicle in Service Mode, propulsion system active, with a scan tool, verify that the Hybrid Electronics Coolant Pump Command is between 20%-90% and Hybrid Electronics Coolant Pump Feedback is 50% +/-5%.

Danger: Any hybrid/EV battery pack replacement shall be performed by High-Voltage Qualified Technicians only. The replacement procedure can be found in the service instruction and must be strictly followed at all times. The High-Voltage Qualified Technician is responsible for adherence to the manufacturer's service instructions as well as current national legal regulations. If the hybrid/EV battery pack needs to be replaced contact the Technical Assistance Centre for further instructions prior to removal of the battery pack.

1. Verify that DTC P0C43, P0C44, P0C45, P0C47, or P1EC6 is not set.

⇒	If DTC is set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .

2. Ignition OFF, disconnect the harness connector at the G35 hybrid/EV electronics coolant pump.
3. Ignition 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 Ω 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 the earth circuit terminal 4.
5. Vehicle in Service Mode, verify that a test lamp illuminates between the B+ circuit terminal 5 and earth 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 G35 hybrid/EV electronics coolant pump.

6. Connect a test lamp between the enable circuit terminal 1 and the earth circuit terminal 4.
7. Command the Hybrid Battery Pack Coolant Pump Command OFF (10%) and ON (90%) with a scan tool. The test lamp should turn 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-circuit 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-circuit to earth or an open-circuit/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 terminal3 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-circuit to voltage or an open-circuit/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-circuit to earth. If the circuit tests normal, replace the K114B hybrid/EV powertrain control module 2.

10. Verify the scan tool Hybrid/EV Electronics Coolant Pump Feedback parameter is less than 10%.

⇒	If greater than the specified range, test the feedback circuit terminal 2 for a short-circuit to earth. 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 earth circuit terminal 4. Verify that the scan tool, Hybrid/EV Electronics Coolant Pump Feedback parameter is greater than 90%.

⇒	If less that the specified range, test the feedback circuit for a short-circuit to voltage or an open-circuit/high resistance. If the circuit tests normal, replace the K114B hybrid/EV powertrain control module 2.

12. If all circuits test normal, replace the G35 hybrid/EV electronics coolant pump.

Perform the Diagnostic Repair Verification after completing the repair.