Symptoms

- Engine Light ON (or Service Engine Soon Warning Light)

Possible Causes

- VDC/TCS/ABS to ECM circuit harness is open or shorted - TCM to ECM circuit harness is open or shorted - VDC/TCS/ABS to ECM circuit connectors - TCM to ECM circuit connectors - Faulty revolution sensor

When Detected

Malfunction is detected when ECM detects a difference between two vehicle speed sensor signals is out of the specified range.

Description

The Engine Control Module (ECM) receives two vehicle speed sensor signals via the Control Area Network (CAN) communication line. One is sent from Vehicle Dynamic Control (VDC) / Traction Control System (TCS) / Anti-Lock Brake System (ABS) control unit, and the other is from Transmission Control Module (TCM). ECM uses these two signals for engine control.