P1720 Vehicle Speed Meter Circuit Malfunction

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

What about the obd code?

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

Symptoms

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

P1720 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.