GM Service Manual Online
For 1990-2009 cars only

Diagnostic Instructions

    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC P0716: Input Speed Sensor Performance

DTC P0717: Input Speed Sensor Circuit Low Voltage

Diagnostic Fault Information

Circuit

Short to Ground

Open/High Resistance

Short to Voltage

Signal Performance

Input Speed Sensor Supply Voltage

P0716, P0717

P0716, P0717

P0716, P0717

P0716

Input Speed Sensor Signal

P0716, P0717

P0716, P0717

P0716, P0717

P0716

Circuit/System Description

The input speed sensor (ISS) is a permanent magnet generator. The ISS mounts in the transmission case in front of the valve body assembly. The sensor faces the reverse clutch housing machined teeth surface. As the reverse clutch housing rotates, an AC voltage is induced and transmitted to the transmission control module (TCM). The AC voltage level and the number of pulses increase as the speed of the reverse clutch housing increases. The TCM converts the AC voltage into a digital signal. The TCM uses the input shaft speed signal to help determine line pressure, transmission shift patterns, torque converter clutch (TCC) slip speed and gear ratio.

Conditions for Running the DTC

P0716

    • No TP sensor DTC P0120.
    • No ISS DTC P0717.
    • No output speed sensor (OSS) DTCs P0722 or P0723.
    • No Shift Solenoid DTCs P0757, P0973, P0974.
    • The engine torque is at least 50 N·m (37 lb ft).
    • The vehicle speed is 16 km/h (10 mph) or greater.
    • The transmission input shaft speed is greater than 1,050 RPM for 2 seconds.
    • The throttle position is at least 8 percent.
    • One of the following conditions exist:
       - The transmission input shaft speed has not decreased more than 1,050 RPM for at least 2 seconds.
       - The transmission input shaft speed has increased by greater than 500 RPM within 2 seconds.

P0717

    • No ISS DTC P0717.
    • No OSS DTCs P0722 or P0723.
    • The vehicle speed is greater than 16 km/h (10 mph).
    • The engine torque is at least 50 N·m (37 lb ft).

Conditions for Setting the DTC

P0716

The change in transmission input shaft speed is 1,000 RPM or more for 4 seconds.

P0717

The transmission input shaft speed is less than 50 RPM for 5 seconds.

Action Taken When the DTC Sets

    • DTC P0716 and P0717 are Type B DTCs.
    • The TCM commands maximum line pressure.
    • The TCM freezes transmission adapts.
    • The TCM calculates input speed from the automatic transmission output shaft speed sensor and commanded gear.

Diagnostic Aids

    • Inspect the connectors at the TCM, the AT ISS, and all other circuit connecting points for an intermittent condition. Refer to Testing for Intermittent Conditions and Poor Connections.
    • Inspect the circuit wiring for an intermittent condition. Refer to Testing for Electrical Intermittents.
    • Road test the vehicle while monitoring the Transmission ISS parameter on the scan tool. The Transmission ISS parameter should vary with engine speed changes and not abruptly drop out.
    • Inspect for an open or shorted AT ISS wire.
    • Inspect for a disconnected AT ISS connector.
    • Inspect for a faulty AT ISS.

Conditions for Clearing the DTC

DTCs P0716 and P0717 are Type B DTCs.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Transmission General Information

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions

Scan Tool Reference

Transmission Control Module Scan Tool Information

Special Tools

    • J 38522 Variable Signal Generator
    • J 44152 Jumper Harness (20 Pins)

Circuit/System Verification

  1. Engine idling, observe the scan tool Transmission ISS parameter while varying the engine speed. The Transmission ISS parameter should change with the engine speed and not drop out.
  2. Operate the vehicle within the Conditions for Running the DTC. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.

Circuit/System Testing

    Important: Additional DTC’s may set when disconnecting the automatic transmission inline 20-way connector.

  1. Ignition OFF, disconnect the AT harness connector at the transmission.
  2. Install the J 44152 on the engine side of the AT inline 20-way connector.
  3. Ignition ON, verify that a test lamp illuminates between the ignition circuit terminal E and ground.
  4. If the test lamp does not illuminate, test the ignition circuit for a short to ground or an open/high resistance. If the circuit tests normal and the ignition circuit fuse is open, test all components connected to the ignition circuit and replace as necessary.
  5. Ignition OFF, connect the red lead of the J 38522 to the signal circuit terminal K. Connect the battery voltage supply to B+, and ground the black lead.
  6. Set the J 38522 signal to 12 volts, the Frequency to 300, and the Duty Cycle to 50 percent.
  7. Ignition ON, observe the scan tool Transmission ISS parameter. The scan tool Transmission ISS parameter should be between 500-700 RPM.
  8. If not within the specified range, test the signal circuit for a short to voltage, a short to ground, or an open/high resistance. If the circuit tests normal, replace the TCM.
  9. Ignition OFF, remove the transmission oil pan. Refer to Automatic Transmission Fluid and Filter Replacement.
  10. Test the internal transmission wiring harness for the ISS for the conditions listed below. The circuits should test normal.
  11. • Open
    • Short to ground
    • Short to voltage
    If you find a condition, replace the internal transmission wiring harness. Refer to Torque Converter Clutch Pulse Width Modulation Solenoid, Torque Converter Clutch Solenoid, and Wiring Harness.
  12. If all circuits test normal, test or replace the input speed sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

    •  Input Speed Sensor Removal and Input Speed Sensor Installation
    •  Automatic Transmission Fluid and Filter Replacement
    •  Torque Converter Clutch Pulse Width Modulation Solenoid, Torque Converter Clutch Solenoid, and Wiring Harness
    •  Control Module References for TCM replacement, setup, and programming