GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Equinox 🢒 Brakes 🢒 Park Brake 🢒 DTC P0703

Circuit Description

Brake switch information is sent to the transmission control module (TCM) by the powertrain control module (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 P0703 to set by itself. If a CAN fault occurs, other DTCs will set before DTC P0703.

When the PCM sends the TCM an invalid brake switch signal, then DTC P0703 will set. DTC P0703 is a type C DTC.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0703 Brake Switch Circuit

Conditions for Running the DTC
    • No CAN DTC U2105.
    • Trans. Protection Mode OFF.
    • The ignition has been ON for at least 3.0 seconds.

Conditions for Setting the DTC

The brake switch signal is invalid for 4.0 seconds.

Action Taken When the DTC Sets
    • The TCM requests the PCM to illuminate the service vehicle soon (SVS) lamp if equipped.
    • 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 PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as a Freeze Frame.
    • The TCM stores DTC P0703 in TCM history.

Conditions for Clearing the SVS Lamp/DTC
    • The TCM turns OFF the SVS Lamp/DTC if equipped after the third consecutive drive trip in which the TCM does not send a SVS Lamp message request.
    • A scan tool can clear the SVS Lamp/DTC if equipped.
    • 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 default actions when the ignition is OFF long enough in order to power down the TCM.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle in Vehicle DTC Information?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2
  1. Install a scan tool.
  2. Turn the ignition ON, 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 PCM and the 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 ECM Failure Records?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

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 P0703 reset?

--

Go to Step 4

Go to Intermittent Conditions in Engine Controls - 3.4L

4

Did any other DTCs set?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

Go to Step 5

5

Replace the PCM. Refer to Control Module References in Computer/Integrating Systems 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 the engine and vary the throttle.
  4. Select Specific DTC.
  5. Enter DTC P0703.

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 in Vehicle DTC Information

System OK