ZF 4HP 16 - Automatic Transmission

DTC P0717

Circuit Description

Information relative to transaxle input speed to the transmission control module (TCM). The TCM uses transaxle input speed information to control line pressure, torque converter clutch (TCC) apply and release, and transaxle shift patterns. This information is also used to calculate the appropriate operating gear ratios and TCC slippage.

The input speed sensor mounts onto piston B that is inside of the valve body.

An air gap of 1.8-2.2 mm (0.07-0.086 in) is maintained between the sensor and the piston B.

The sensor consists of a permanent magnet surrounded by a coil of wire. As the piston B is driven by the turbine shaft, an AC signal is induced by the input speed sensor. Higher vehicle speeds induce a higher frequency and voltage measurement at the sensor.

Sensor resistance should measure between 825-835 ohms at 20°C (68°F). The sensor can measure from 1,000-8,000 Hz.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0717 Input Speed Sensor Circuit Low Voltage

Conditions for Setting the DTC

* When engine speed (RPM) is more than 3,100 RPM, turbine speed is less than 100 RPM.
* System voltage is too high or too low.
* CAN transmitting wiring harness shortage or open
* The TCM or engine control module (ECM) is defective.
* Immediately after the above condition occurs

Action Taken When the DTC Sets

* The malfunction indicator lamp (MIL) will illuminate
* The TCM will record operating conditions at the time the diagnostic fails. This information will be stored in the Failure Records buffer.
* Adopt Emergency/Substitute mode and constant 4th gear by hydraulic control.
* After ignition OFF/ON : 3rd gear by hydraulic control, position P, R and N also possible.
* Open lock up clutch

Conditions for Clearing the MIL/DTC

* The MIL will turn OFF when the malfunction has not occurred after 3 ignition cycles.
* A history DTC will clear after 40 consecutive warm-up cycles without a fault.
* Using a scan tool can clear history DTCs.

Diagnostic Aids

When DTC P0717 sets, the possible cause of fault could be the input speed sensor (ISS).