P0C2B
DTC P0C2B
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 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 12 v direct current (dc) into 12 v, 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 ignition switch is in the RUN position.
* Ignition voltage is 8-18 volts.
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.
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 (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
Special Tools
J 38522 - Variable Signal Generator
For equivalent regional tools, refer to Special Tools (Hybrid Controls).
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. Inspect for DTC B1433.
• If DTC B1433 is set, diagnose and repair it prior to performing this diagnostic.
2. Ignition OFF, disconnect ATFP control module X1 connector.
3. Ignition ON, test for battery voltage on the ATFP battery circuit, from ATFP vehicle harness side X1 connector terminal 4 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.
Note: If an open ground condition is observed, inspect the 3 phase motor shield circuit and terminal for damage.
4. Test for battery voltage on the ATFP battery circuit from ATFP vehicle harness side X1 connector terminal 4 and the ATFP control module ground circuit connector X1 terminal 5.
• If less than the specified range, test the ATFP ground circuit for an open/high resistance. If the circuit tests normal, continue with diagnosis.
5. Test for battery voltage on the ATFP control module ignition circuit from ATFP vehicle harness side X1 connector terminal 2 and the ATFP control module ground circuit connector X1 terminal 5.
• If less than the specified range, test the ATFP vehicle harness side ignition circuit for an open/high resistance or a short to ground. If the circuit tests normal, continue with diagnosis.
6. Test for 4.8-5.2 volts on the Trans. Aux. Oil Pump Diagnostic circuit, from the ATFP control module X1 connector terminal 1 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 control module X1 connector terminal 1, 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