GM Service Manual Online
For 1990-2009 cars only

Circuit Description

This diagnostic trouble code (DTC) indicates that an emission related transmission DTC set in the transmission control module (TCM). The engine control module (ECM) receives the TCM DTC information over the serial data circuit. The ECM turns ON the malfunction indicator lamp (MIL) when the TCM sends a message over the serial data circuit requesting MIL illumination. The ECM will also store the freeze frame/failure records data for a transmission DTC. The DTC information for the ECM will only display DTC P0700, but the freeze frame/failure records data will display the transmission DTC that 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

Conditions for Clearing the MIL/DTC

    • The control module turns OFF the malfunction indicator lamp (MIL) after 4 consecutive ignition cycles that the diagnostic runs and does not fail.
    • A current DTC, Last Test Failed, clears when the diagnostic runs and passes.
    • 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.

Action Taken When the DTC Sets

    • The Malfunction Indicator Lamp (MIL) will illuminate.
    • The ECM will record operating conditions at the time the diagnostic fails. This information will be stored in the Freeze Frame and/or Failure Records buffers.

Diagnostic Aids

An intermittent may be caused by a poor connection, rubbed-through wire insulation or a wire broken inside the insulation.

Check for a poor connector or damaged ECM/TCM harness. Inspect the serial data link circuit for the following conditions:

    • Improper mating
    • Broken locks
    • Improperly formed
    • Damaged terminals
    • Poor terminal-to-wiring connections
    • Damaged harness

Step

Action

Yes

No

1

Did you perform the Diagnostic System Check - Engine Controls?

Go to Step 2

Go to Diagnostic System Check - Engine Controls

2

  1. Start the engine.
  2. Allow the engine to reach the normal operating temperature.
  3. Observe the DTC Information with a scan tool.

Does the scan tool display any ECM DTCs other than DTC P0700?

Go to Diagnostic Trouble Code (DTC) List

Go to Diagnostic System Check - Automatic Transmission in Automatic Transmission - Aisin (81-40LE)