DTC P1700: Transmission Control Module (TCM) Requested Mil: Description

This DTC indicates that an emissions related transmission fault has occurred. Transmission Control Module (TCM) flashes sport mode lamp when a fault occurs on certain non-emissions related TCM systems. TCM has no direct control of Malfunction Indicator Lamp (MIL), but if a transmission fault occurs that is emissions related, MIL must illuminate. TCM transmits a MIL request signal over the CAN bus to ECM and ECM will turn on MIL. This allows MIL to illuminate, even though fault was detected by TCM.