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Input shaft speed sensor

Input shaft speed sensor

The input shaft speed sensor is mounted in the transmission casing. It provides the control module with information on the speed of the transmission's input shaft on pin 45. The sensor is grounded via pin 44.

The sensor is electromagnetic (inductive) and measures the input speed after the torque converter (turbine speed) when it is affected by a toothed wheel (C1 clutch drum). The control module uses the frequency to calculate the input speed. The signal voltage of the sensor increases with the engine speed. At idling speed, the voltage is 1.2-1.4 V AC and at 2500 rpm it is 2.2 V AC.

The resistance across the pins is 300-600 ohms.

The control module uses the input speed and the vehicle speed to calculate shifting times. Information on input and vehicle speeds affects the fluid pressure control, the control of the Lock-up function and the engine torque reduction, which results in smoother shifting.



Diagnostics

If the gearbox input speed is absent, diagnostic trouble code P0717 will be generated.

The TCM goes into Limp-Home mode.