For 1990-2009 cars

### 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 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 DTC information for the ECM will only display DTC P0700.

### 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 Setting the DTC

The ECM receives a serial data message, from the TCM, in order to illuminate the MIL.

### Action Taken When the DTC Sets

• | The control module illuminates the malfunction indicator lamp (MIL) when the diagnostic runs and fails.

• | The control module records the operating conditions at the time the diagnostic fails. The control module stores this information in the Failure Records.

Step | Action | 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 and record any powertrain DTCs other than DTC P0700. Did you complete the action? | Go to Diagnostic Trouble Code (DTC) List - Vehicle | --