P15F9

DTC P15F9

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 a overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor
DTC P15F9
- Hybrid System Engine Speed Control Intervention Request Type Signal Message Counter Incorrect

Circuit/System Description

To improve shift feel, the hybrid powertrain control module (HPCM) is constantly sending the engine control module (ECM) serial data messages with information regarding it's request for modifying engine speed or torque. The serial data messages are sent through two circuits which are part of a communication network called the controller area network (CAN). The ECM sets DTC P15F9 when it detects a discrepancy in the structure of the message causing the integrity of the message to be questioned.

An intermittent fault in the CAN circuits will cause the ECM to set DTC P15F9.

Conditions for Running the DTC

* The engine run time is greater than 0.5 s.
* DTC U1817 is not set.
* No other CAN errors are present.

Conditions for Setting the DTC

The ECM detects that the engine speed and torque modification messages from the HPCM are either corrupted or intermittently missing for greater than 4 s.

Action Taken When the DTC Sets

* DTC P15F9 is a Type B DTC.
* The TCM commands maximum line pressure during shifts, which results in harsh shifts.
* The TCM freezes adaptive functions.

Conditions for Clearing the DTC

DTC P15F9 is a Type B DTC.

Reference Information
Description and Operation

Hybrid Modes of Operation Description Hybrid Modes of Operation Description
DTC Type Reference

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

Diagnostic Repair Verification Verification Tests

Circuit/System Verification

1. DTC P15F9 is an informational DTC. Diagnose all other engine control DTCs prior to DTC P15F9. Refer to Diagnostic Trouble Code (DTC) List - Vehicle Diagnostic Trouble Code (DTC) List - Vehicle.
2. If there are no other engine controls DTCs, diagnosis is accomplished by looking for an intermittent CAN circuit fault. Refer to Scan Tool Does Not Communicate with High Speed GMLAN Device Scan Tool Does Not Communicate with High Speed GMLAN Device.

Repair Instructions

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

Control Module References Control Module References for control module replacement, setup, and programming.