Faulty Transmission Input Speed Sensor
Transmission Input Speed Sensor harness is open or shorted
Transmission Input Speed Sensor circuit poor electrical connection
Faulty Control Solenoid Valve Assembly
Engine Light ON (or Service Engine Soon Warning Light)
The Input Speed Sensor detects the primary pulley revolution speed and sends a signal to the Transmission. The Input Speed Sensor (ISS), also known as the transmission turbine speed sensor, is a hall-effect type sensor. The ISS mounts to the control valve upper body assembly and connects to the control solenoid (w/body and Transmission Control Module (TCM)) valve assembly through a wire harness and connector. The sensor faces the 1-2-3-4 and 3-5-R clutch housing machined teeth surface. The sensor receives 8.3-9.3 volts on the Input/Output Speed Sensor (ISS/OSS) supply voltage circuit from the Transmission Control Module (TCM). As the 1-2-3-4 and 3-5-R clutch housing rotates, the sensor produces a signal frequency based on the machined surface of the 1-2-3-4 and 3-5-R clutch housing. This signal is transmitted through the ISS signal circuit to the control solenoid (w/body and TCM) valve assembly. The control solenoid (w/body and TCM) valve assembly uses the ISS signal to determine line pressure, transmission shift patterns, Torque Converter Clutch (TCC) slip speed, and gear ratio. The Diagnostic Trouble Code (DTC) will be set when the TCM detects the ISS signal circuit voltage is less than 0.25 V for 0.8 s.