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 Descriptors

DTC P0717: Input Speed Sensor Circuit Low Voltage

DTC P0722: Output Speed Sensor Circuit Low Voltage

Circuit/System Description

The input speed sensor (ISS) and output speed sensor (OSS) are 2 wire magnetic pick-up type sensors. The ISS produces 20 pulses for each input shaft revolution. The OSS produces 12 pulses for each output shaft revolution.

Conditions for Running the DTC

P0717

    • No transmission range (TR) Switch DTC P0705.
    • No transmission fluid temperature (TFT) Sensor DTCs P0711, P0712, or P0713.
    • Vehicle Speed greater than 7 km/h (4 mph).
    • The engine is running for greater than 2 seconds.
    • The transmission is not in Emergency Mode.

P0722

    • No TR Switch DTC P0705.
    • No TFT Sensor DTCs P0711, P0712, or P0713.
    • Vehicle Speed greater than 7, 13, 18, or 26 km/h (4, 8, 11 or 16 mph) for 1st, 2nd, 3rd, or 4th gear respectively.
    • The engine is running for greater than 2 seconds.
    • The transmission is not in Emergency Mode.

Conditions for Setting the DTC

P0717

The TCM detects no pulse signal from Input Speed sensor when there are 6 pulses from the Output Speed sensor, 500 occurrences.

P0722

Fail Case 1 : The TCM detects no pulse signal from Output Speed sensor when there are 10 pulses from the Input Speed sensor, 500 occurrences.

Action Taken When the DTC Sets

P0717

    • DTC P0717 is a Type A DTC.
    • The transmission will operate in 4th gear in D range, Reverse in R range.
    • Input speed defaults to 0 RPM.

P0722

    • DTC P0722 is a Type A DTC.
    • The transmission will operate in 4th gear in D range, Reverse in R range.
    • Output speed is calculated from input speed.

Conditions for Clearing the DTC

DTCs P0717 and P0722 are Type A DTCs.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Electronic Component Description

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

Control Module References

Circuit/System Verification

  1. Engine idling, observe the scan tool ISS parameter while varying the engine speed. The ISS parameter should vary with the engine speed and not drop out.
  2. Operate the vehicle at 16-32 km/h (10-20 mph) while observing the scan tool OSS parameter. The OSS should vary with the vehicle speed and not drop out.
  3. 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.

Circuit/System Testing

  1. Ignition OFF, disconnect the appropriate Speed Sensor Connector harness.
  2. Ignition ON, Test for 9-12 volts between the high and low signal circuits, from the TCM.
  3. If not within the specified range, replace the TCM.
  4. If the circuits test normal, test or replace the speed sensor.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

    •  Control Module References for TCM replacement, setup, and programming
    •  Input and Output Speed Sensor Removal
    •  Input and Output Speed Sensor Installation