GM Service Manual Online
For 1990-2009 cars only

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).

P0717

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Install the scan tool.
  2. Turn the ignition ON, with the engine OFF.
  3. Record then clear the DTCs.
  4. Turn the ignition OFF, then turn the ignition ON.
  5. Observe the input speed on the scan tool.

Is the speed within the specified value?

100 RPM

Go to Diagnostic Aids

Go to Step 3

3

  1. Turn the ignition OFF.
  2. Disconnect the transaxle wiring connector.
  3. Measure the resistance between terminals 15 and 16 of the transaxle wiring connector.

Is the resistance within the specified value?

825-835 ohms

Go to Step 9

Go to Step 4

4

  1. Remove the oil pan.
  2. Disconnect the input speed sensor wiring connector.
  3. Measure the resistance between terminal 1 of the input speed sensor wiring connector and terminal 15 of the transaxle wiring connector.
  4. Measure the resistance between terminal 2 of the input speed sensor wiring connector and terminal 16 of the transaxle wiring connector.

Is the resistance approximately equal to the specified value?

0 ohms

Go to Step 6

Go to Step 5

5

Repair the malfunctioning terminals, as necessary.

Is the action complete?

--

System OK

--

6

  1. Turn the ignition ON, with the engine OFF.
  2. Measure the voltage of terminal 1.
  3. Measure the voltage of terminal 2.

Is the voltage within the specified value?

11-14 V

Go to Step 7

Go to Step 8

7

Repair the short to battery power.

Is the action complete?

--

System OK

--

8

Replace the input speed sensor.

Is the action complete?

--

System OK

--

9

  1. Disconnect the transaxle wiring connector and transmission control module (TCM) connector.
  2. Measure the resistance between terminal 15 of the transaxle wiring connector and terminal B4 of the TCM wiring connector.
  3. Measure the resistance between terminal 16 of the transaxle wiring connector and terminal B2 of the TCM wiring connector.

Is the resistance approximately equal to the specified value?

0 ohms

Go to Step 11

Go to Step 10

10

Repair the malfunctioning terminals, as necessary.

Is the action complete?

--

System OK

--

11

  1. Turn the ignition ON, with the engine OFF.
  2. Measure the voltage of terminal 15.
  3. Measure the voltage of terminal 16.

Is the voltage within the specified value?

11-14 V

Go to Step 12

Go to Step 13

12

Repair the malfunctioning terminals, as necessary.

Is the action complete?

--

System OK

--

13

Replace the TCM. Refer to Transmission Control Module Replacement .

Is the action complete?

--

Go to Step 14

--

14

  1. After the repair, use a scan tool "clear info" function.
  2. Road test the vehicle.
  3. Review the DTC info.

Has the last test failed or is the current DTC displayed?

--

Go to Step 2

System OK