P0C2B

DTC P0C2B

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptor
DTC P0C2B
- Auxiliary Transmission Fluid Pump Control Feedback Circuit

Diagnostic Fault Information





Typical Scan Tool Data









Circuit/System Description

The auxiliary transmission fluid pump (ATFP) system supplies the transmission with hydraulic pressure when the vehicle is operating in the internal combustion engine (ICE) Autostop hybrid mode. The ATFP system consists of a ATFP control module that operates an electric, 12V 3 phase alternating current (ac), motor-driven pump. Two pulse width modulated (PWM) status circuits connect the ATFP control module to the hybrid powertrain control module (HPCM). The transmission auxiliary oil pump (TAOP) control circuit delivers the HPCM commanded pump speed to the ATFP control module. The transmission auxiliary oil pump (TAOP) diagnostic circuit supplies the HPCM with the actual pump speed and also with the operating status of the ATFP control module. The HPCM monitors these circuits for fault conditions.

The ATFP control module inverts 12V direct current (dc) into 12V, 3 phase ac current to operate the pump motor.

The ATFP control module monitors the status of the ATFP pump as well as its own internal circuitry. The ATFP control module does not store its own diagnostic status. Current ignition cycle diagnostic status is reported to the HPCM on the TAOP diagnostic circuit. The diagnostic status within the ATFP control module is reset at every ignition-off cycle.

Conditions for Running the DTC

* The vehicle is operating in the Autostop hybrid mode.
* Ignition voltage is 9.5-18V.

Conditions for Setting the DTC

The control module has not detected the ATFP diagnostic signal for 1.5 seconds.

Action Taken When the DTC Sets

* DTC P0C2B is a Type B DTC.
* The HPCM disables the Autostop hybrid mode during the first drive trip failure, and also when the DTC sets.

Conditions for Clearing the DTC

DTC P0C2B is a Type B DTC.

Reference Information
Schematic Reference

Hybrid Controls Schematics (Electrical Diagrams)
Connector End View Reference

Component Connector End Views (Connector Views)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information
Special Tools

J 38522 - Variable Signal Generator

Circuit/System Verification

1. Clear the DTC information.
2. Turn the ignition OFF for 1 minute.
3. Turn the ignition ON.
4. Retest for DTC P0C2B.

Circuit/System Testing

1. Ignition OFF, disconnect ATFP X2 connector.
2. Ignition ON, test for battery voltage on the ATFP battery circuit, from ATFP X2 connector terminal B and chassis ground.

• If less than battery voltage, test the ATFP battery circuit for an open/high resistance. If the circuit tests normal, continue with diagnosis.

3. Test for battery voltage on the ATFP battery circuit from ATFP X2 connector terminal B and the ATFP ground circuit connector X2 terminal A.

• If less than the specified range, test the ATFP ground circuit for an open/high resistance. If the circuit tests normal, continue with diagnosis.

4. Disconnect ATFP X3 connector.
5. Test for battery voltage on the ATFP ignition circuit from ATFP X3 connector terminal D and the ATFP ground circuit connector X2 terminal A.

• If less than the specified range, test the ATFP ignition circuit for an open/high resistance. If the circuit tests normal, continue with diagnosis.

6. Test for 4.8-5.2V on the Trans. Aux. Oil Pump Diagnostic circuit, from the ATFP X3 connector terminal B and ground.

• If less than the specified range, test the Trans. Aux. Oil Pump Diagnostic circuit for an open/high resistance or short to ground. If the circuit tests normal, replace the PIM.
• If more than the specified range, test the Trans. Aux. Oil Pump Diagnostic circuit for a short to voltage. If the circuit tests normal, replace the PIM.

7. Connect the J 38522 - variable signal generator red terminal to the Trans. Aux. Oil Pump Diagnostic circuit, ATFP X3 connector terminal B, vehicle harness side. Connect the J 38522 - variable signal generator black terminal to chassis ground.
8. Adjust the signal generator to 50 percent duty cycle @ 250 Hz and observe the Trans. Aux. Pump Actual speed parameter with the scan tool. The scan tool should display 100 percent.

• If less than 100 percent, test the Trans. Aux. Oil Pump Diagnostic circuit for a short to 5V. If the circuit tests normal, replace the PIM.
• If 100 percent is displayed, replace the ATFP control module.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

Control Module References (Programming and Relearning) for PIM or ATFP control module replacement, setup, and programming