GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The transmission control module (TCM) uses the controller area network (CAN) to signal the engine control module (ECM) that the TCM is requesting malfunction indicator lamp (MIL) illumination. This happens when the TCM has determined that a failure that affects emissions has occurred in the transmission control system. When the ECM receives the correct message from the TCM, DTC P0700 will set.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0700 Transmission Control Module (TCM) Requested MIL Illumination

Conditions for Running the DTC

DTC P0700 runs continuously then the ignition is ON.

Conditions for Setting the DTC

The TCM is requesting MIL illumination.

Action Taken When the DTC Sets

    • The control module illuminates the malfunction indicator lamp (MIL) on the TCM request.
    • The control module records the operating conditions at the time the TCM diagnostic fails. The control module stores this information in the Freeze Frame/Failure Records.

Conditions for Clearing the MIL/DTC

    • Any related TCM codes must be cleared before P0700 can be cleared.
    • A history DTC clears after 40 consecutive warm-up cycles, if no failures are reported by this or any other emission related diagnostic.
    • Clear the MIL and the DTC with a scan tool.

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Observe the DTC Information with a scan tool.

Does the scan tool display any engine control module (ECM) DTCs other than P0700?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle

Go to Step 3

3

Return to the Diagnostic Trouble Code (DTC) List - Vehicle and select the appropriate transmission DTC.

Did you complete the action?

--

System OK

--