Volt

Cooling Fan Malfunction - DTC P148A-P148C

The hybrid/EV powertrain control module 2 controls the radiator cooling fans. The cooling fans are controlled with a pulse width modulated (PWM) signal. The hybrid/EV powertrain control module 2 diagnoses any faults with the hardwire circuit to the engine control module. The engine control module sends a fan request PWM signal to the hybrid/EV powertrain control module 2 through a hardwire circuit. The hybrid/EV powertrain control module 2 operates in a pass-through mode for the engine control module fan request. The higher the duty cycle the higher the cooling fan speed.

P148A

P148B

The 12 V battery voltage is greater than or equal to 9 V.

P148C

P148A

The PWM fan duty cycle request from engine control module (Hardwire) is not within 30% of the requested engine cooling fan speed sent to the hybrid/EV powertrain control module 2 via serial data.

P148B

The hybrid/EV powertrain control module 2 has detected a duty cycle of greater than 97% from the engine control module.

P148C

The hybrid/EV powertrain control module 2 has detected a duty cycle of less than 3% from the engine control module.

DTCs P148A, P148B and P148C are type B DTCs.

DTCs P148A, P148B and P148C are type B DTCs.

Schematic Reference

Engine 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, with a scan tool, command the Cooling Fan Motor Command ON. Verify that the Cooling Fan Motor Command is greater than 0% and the cooling fans operate.

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. Ignition OFF, disconnect the X1 harness connector at the K20 engine control module.
2. Vehicle in Service Mode, test for 4.8-5.2 V between the signal circuit terminal 41 and earth.

⇒	If less than the specified range, test the signal 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.

⇒	If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the K114B hybrid/EV powertrain control module 2.

3. If all circuits test normal, replace the K20 engine control module.

Perform the Diagnostic Repair Verification after completing the repair.

Control Module References for engine control module or hybrid/EV powertrain control module 2 replacement, programming and set-up