GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0700: Transmission Control Module (TCM) Requested MIL Illumination

Circuit/System Description

This DTC indicates that an emission related transmission DTC has set in the transmission control module (TCM). The engine control module (ECM) turns ON the malfunction indicator lamp (MIL) when the TCM sends a message over the serial data circuit requesting MIL illumination.

Conditions for Running the DTC

    • The ignition is ON.
    •  DTC P0700 runs continuously.

Conditions for Setting the DTC

Serial Data communication from the TCM indicates a fault exists with the transmission.

Action Taken When the DTC Sets

DTC P0700 is a Type A DTC.

Conditions for Clearing the MIL/DTC

DTC P0700 is a Type A DTC.

Reference Information

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Circuit/System Verification

  1. DTC P0700 is an informational DTC. If there are any engine controls DTCs in the ECM or TCM, refer to Diagnostic Trouble Code (DTC) List - Vehicle.
  2. Engine running, observe the DTC information with a scan tool. DTC P0700 should not set.
  3. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.