Control Module: Description and Operation

A/T Control
These circuit lines are used to control the smooth shifting up and down of A/T during the hard acceleration/ deceleration.

Voltage signals are exchanged between ECM and TCM (Transmission Control Module).

A/T Diagnosis Communication Line
The malfunction information related to OFF (Automatic Transmission) is transferred through the line (circuit) from TCM (Transmission control module) to ECM. Therefore, be sure to erase the malfunction information such as DTC not only in TCM (Transmission control module) but also ECM after the A/T related repair.