GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Pontiac 🢒 2006 🢒 Torrent 🢒 Transmission/Transaxle 🢒 Automatic Transaxle - AF33-5 🢒 DTC P2544

Circuit Description

To improve shift feel, the transmission control module (TCM) may request that the powertrain control module (PCM) reduce engine torque during shift events. When such a request is received, the PCM responds by retarding the base ignition timing and notifying the TCM that the request has succeeded. If the PCM is unable to comply with the request, the PCM sends the TCM a message that the request has failed.

The torque reduction request is sent to the PCM through a communication network called the controller area network (CAN). Two circuits are used to communicate CAN data between the PCM and TCM. A fault in the CAN will not cause DTC P2544 to set by itself. If a CAN fault occurs, other DTCs will set before DTC P2544.

When the TCM receives a torque reduction failure message from the PCM, then DTC P2544 will set. DTC P2544 is a type C DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P2544 Transmission Torque Request Circuit

Conditions for Running the DTC
    • No CAN DTC U0100.
    • The ignition voltage is 10.2-15.5 volts.
    • The engine speed is 400 RPM or greater.
    • Trans. Protection Mode is OFF.

Conditions for Setting the DTC

The PCM notifies the TCM that a torque reduction request has failed for 0.080 second.

Action Taken When the DTC Sets
    • The TCM increases line pressure.
    • The TCM disables self-learning control.
    • The TCM limits shift lines to 4000 RPM.
    • The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record.
    • The TCM stores DTC P2544 in TCM history.

Conditions for Clearing the MIL/DTC
    • The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring.
    • The TCM cancels the DTC default actions when the ignition is OFF long enough in order to power down the TCM.

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.

    3. Important: 

       • Before clearing the DTC, use the scan tool in order to record the PCM Freeze Frame and the TCM Failure Records. Using the Clear Eng./Trans. DTC Info function erases the Freeze Frame and Failure Records from the powertrain control module (PCM) and the transmission control module (TCM).
       • Using the Clear Eng./Trans. DTC Info function erases stored DTCs in both the PCM and TCM.

  3. Record the DTC Failure Records.

Did you record any PCM Failure Records?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 3

3
  1. Clear the DTC.
  2. Turn the ignition OFF for at least 30 seconds.
  3. Start, and allow the engine to idle.

Did DTC P2544 reset?

Go to Step 4

Go to Testing for Intermittent Conditions and Poor Connections

4

Did any other DTCs set?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 5

5

Replace the PCM. Refer to Control Module References for replacement, setup, and programming.

Is the action complete?

Go to Step 6

--

6

Perform the following operation to verify the repair:

  1. Select DTC on the scan tool.
  2. Select Clear Info.
  3. Start, and allow the engine to idle.
  4. Select Specific DTC.
  5. Enter DTC P2544.

Does the DTC reset?

Go to Step 2

Go to Step 7

7

With the scan tool, observe the stored information, capture info and DTC info.

Does the scan tool display any DTCs that you have not diagnosed?

Go to Diagnostic Trouble Code (DTC) List - Vehicle

System OK