P1540 Chevrolet Vehicle Speed Sensor Malfunction

Possible causes

– Faulty Vehicle Speed Sensor
– Vehicle Speed Sensor harness is open or shorted
– Vehicle Speed Sensor circuit poor electrical connection

Symptoms

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

P1540 Chevrolet Description

The Vehicle Speed Sensor 1 (Output Shaft Rotation Sensor) is mounted to the extension case (from the outside of the case). the sensor outputs a pulse signal which is transmitted to the Transmission Control Module (TCM) where it is converted to vehicle speed.

The transfer clutch drum is connected directly to the rear wheel driving propeller shaft. Vehicle speed sensor 1 on the AWD model detects rear-wheel speed.