DTC P0700: TCM Requested Mil Illumination: Description

WARNING: This page is about a different car, the 2002 Saturn Vue. However, it is still accessible from the selected car via links, so may be relevant.

The Transmission Control Module (TCM) sends the Engine Control Module (ECM) each DTC number over the Controller Area Network (CAN) link as soon as the DTC becomes active. The ECM in turn will determine if the DTC is emission related (type "A" or type "B"). A type "A" DTC will enable the ECM to turn on the MIL (SERVICE ENGINE SOON telltale) during the first ignition cycle after the fault becomes active. A DTC P0700 will be stored and freeze frame/failure record data will be captured. The ECM will store the original DTC the TCM set in the freeze frame only, P0700 will still be the only DTC listed when codes are pulled using the scan tool. A type "B" DTC will enable the ECM to turn on the MIL and set a freeze frame/failure record during the second consecutive ignition cycle if the ECM receives the same DTC from the TCM. Again a P0700 will be the only DTC listed when codes are pulled using the scan tool and the original TCM DTC will appear in the freeze frame/failure record.