DTC P2544
Diagnostic Instructions
DTC Descriptors
DTC P2544: Transmission Torque Request Circuit
DTC P2544: Transmission Torque Request Signal Message Counter Incorrect
Circuit/System Description
To improve shift feel, the transmission control module (TCM) 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 P2544 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 P2544.
Conditions for Running the DTC
| • | The engine run time is greater than 0.5 s. |
| • | No other CAN errors are present. |
Conditions for Setting the DTC
The ECM detects that the engine speed and torque modification messages from the TCM are either corrupted or intermittently missing for greater than 4 s.
Action Taken When the DTC Sets
| • | DTC P2544 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 P2544 is a Type B DTC.
Reference Information
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Circuit/System Verification
- DTC P2544 is an informational DTC. Diagnose all other engine control DTCs prior to DTC P2544. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- 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 .
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for TCM replacement, setup, and programming.
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