The automatic transmission ISS is a permanent magnet with a coil of wire wound around it. The ISS mounts in the case cover facing the reluctor wheel of the input shaft. As the reluctor wheel is driven by the turbine shaft, an AC signal is induced in the input speed sensor. Higher vehicle speeds induce a higher frequency and a higher voltage at the sensor. There is a fixed air gap between the sensor and the teeth on the sensor reluctor wheel. The ISS input is used by the powertrain control module (PCM) in order to control line pressure, torque converter clutch (TCC) apply and release, and transmission shift patterns. This sensor is also used to calculate the appropriate gear ratios and TCC slippage.

P0716

P0717

P0716

The input shaft speed changes by 1,300 RPM or greater for 0.8 second.

P0717

The input shaft speed is less than 100 RPM for 5 seconds.

DTC P0716 and P0717 are type B DTCs.

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation Reference

Electrical Information Reference

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Control Module References for scan tool information

Special Tools

Start the engine in PARK and observe the transmission ISS on the scan tool while varying the engine speed. The transmission ISS should vary with the engine speed and not drop out.

Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.

1. Ignition OFF, using the J 44257 main wiring harness connector remover, disconnect the automatic transmission inline 20-way connector and install the J 44152 jumper harness on the transmission pass-thru connector.
2. Using the light blue J 35616-65B test probe from the J 35616-D GM terminal test kit, test for between 820-1,428 ohms between the ISS high signal circuit, jumper harness pin S, and the ISS low signal circuit, jumper harness pin V.

⇒	If greater than the specified range, test the affected circuits for an open/high resistance. If both circuits test normal, replace the ISS.

⇒	If less than the specified range, test the affected circuits for a shorted together condition. If both circuits test normal, replace the ISS.

3. Test for greater than 10K ohms between the ISS high signal circuit, jumper harness pin S, and all other circuits of the J 44152 jumper harness, except the ISS low signal circuit, jumper harness pin V.

⇒	If less than the specified range, the affected circuits are shorted together. Replace the transmission internal wire harness.

4. Test for greater than 250 ohms from the ISS high signal circuit, jumper harness pin S, and the ISS low signal circuit, jumper harness pin V, to the transmission case.

⇒	If less than the specified value, test the affected circuits for a short to the transmission case. If both circuits test normal, replace the ISS.

5. Using the J 44257 main wiring harness connector remover, remove the J 44152 jumper harness from the transmission pass-thru connector and install it on the engine side of the automatic transmission inline 20-way connector.
6. Disconnect the X3 harness connector at the PCM.

Important: When probing a terminal for testing procedures, it is imperative to use the proper test probe from the J 35616-D GM terminal test kit. Prior versions of the J 35616 GM terminal test kit do not contain the proper probes for testing TCM/ECM/PCM connectors. TCM/ECM/PCM harnesses use 0.64 mm (0.03 in) round terminals. The correct probe for this size terminal is the light blue J 35616-64B probe. ALL PREVIOUS J 35616-64 AND J 35616-64A PROBES SHOULD BE DISCARDED. The 1.00 mm (0.04 in) brown J 35616-6 probe is most widely mistaken for use with 0.64 mm (0.03 in) terminals. Use of the 1.00 mm (0.04 in) brown probe in a 0.64 mm (0.03 in) terminal will deform the terminal, likely resulting in an intermittent open condition.

7. Using the light blue J 35616-64B probes from the J 35616-D GM terminal test kit, test for greater than 250 ohms from the ISS high signal circuit, jumper harness terminal S, and the ISS low signal circuit, jumper harness terminal V, to a good ground.

⇒	If less than the specified value, test the affected circuit for a short to ground.

8. Using the light blue J 35616-64B probes, test for greater than 10K ohms between the ISS high signal circuit, jumper harness terminal S, and all other circuits of the J 44152 jumper harness.

⇒	If less than the specified value, the affected circuits are shorted together.

9. Using the light blue J 35616-64B probes, test for greater than 10K ohms between the ISS low signal circuit, jumper harness terminal V, and all other circuits of the J 44152 jumper harness.

⇒	If less than the specified value, the affected circuits are shorted together.

10. Using the light blue J 35616-64B probes, test the ISS high signal circuit for less than 10 ohms between the J 44152 jumper harness terminal S and terminal 11 PCM X3.

⇒	If greater than the specified value, repair the open or high resistance in the affected circuit.

11. Using the light blue J 35616-64B probes, test the ISS low signal circuit for less than 10 ohms between the J 44152 jumper harness terminal V and terminal 49 PCM X3.

⇒	If greater than the specified value, repair the open or high resistance in the affected circuit.

12. Using a 5A fused jumper wire and the light blue J 35616-64B probes, test for greater than 10K ohms between the ISS high signal circuit, terminal 11 PCM X3, and all other circuits of PCM X3.

⇒	If less than the specified value, the affected circuits are shorted together.

13. Using a 5A fused jumper wire and the light blue J 35616-64B probes, test for greater than 10K ohms between the ISS low signal circuit, terminal 49 PCM X3, and all other circuits of PCM X3.

⇒	If less than the specified value, the affected circuits are shorted together.

14. If all circuits and connections test normal, replace the PCM.

1. Ignition OFF, using the J 44257 main wiring harness connector remover, disconnect the automatic transmission inline 20-way connector and install the J 44152 jumper harness on the transmission pass-thru connector.
2. Using the light blue J 35616-65B test probe from the J 35616-D GM terminal test kit, test for between 820-1,428 ohms between the ISS high signal circuit, jumper harness pin S, and the ISS low signal circuit, jumper harness pin V.

⇒	If greater than the specified range, test the affected circuits for an open/high resistance. If both circuits test normal, replace the ISS.

⇒	If less than the specified range, test the affected circuits for a shorted together condition. If both circuits test normal, replace the ISS.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.