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 P0716: Input Speed Sensor (ISS) Circuit PerformanceDTC P0717: Input Speed Sensor (ISS) Circuit Low Voltage
Diagnostic Fault Information
Circuit | Short to Ground | Open/High Resistance | Short to Voltage | Signal Performance |
|---|---|---|---|---|
ISS Low Signal | -- | P0716, P0717 | -- | P0716 |
ISS High Signal | P0716, P0717 | P0716, P0717 | P0716, P0717 | P0716 |
Circuit/System Description
The automatic transmission input speed sensor (ISS) is a permanent magnet. 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 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 transmission control module (TCM) 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. This diagnostic indicates stuck, erratic, or intermittent conditions in the system.
Conditions for Running the DTC
P0716
| • | DTCs P0121, P0122, P0123, P0717, P0722, P0723, P0752, P0973, or P0974 are not set. |
| • | The ignition voltage is between 8 and 18 volts. |
| • | The engine speed is between 500 and 6,500 RPMs for 5 seconds. |
| • | The throttle position (TP) sensor is 8 percent or greater. |
| • | The vehicle speed is 16 km/h (10 mph) or greater. |
| • | The transmission input shaft speed is greater than 1,050 RPM or greater for 2 seconds. |
| • | The transmission input shaft speed has not changed by 500 RPM or less for 2 seconds. |
| • | The engine torque is between 50-1,492 N·m (37-1,100 lb ft). |
P0717
| • | DTCs P0722, or P0723 are not set. |
| • | The ignition voltage is between 8 and 18 volts. |
| • | The engine speed is between 500 and 6,500 RPMs for 5 seconds. |
| • | The vehicle speed is 16 km/h (10 mph) or greater. |
| • | The engine torque is between 50-1,492 N·m (37-1,100 lb ft). |
Conditions for Setting the DTC
P0716
The transmission input shaft speed drops by 1,000 RPM or more for 3.25 seconds.
P0717
The transmission input shaft speed is less than 100 RPM for 4.5 seconds.
Action Taken When the DTC Sets
P0716 and P0717 are Type B DTCs.
Conditions for Clearing the DTC
P0716 and P0717 are Type B DTCs.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Description and operation
Transmission General Description
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Special Tools
| • | J 35616 GM-Approved Terminal Test Kit |
| • | J 44152 Jumper Harness (20 pins) |
Circuit/System Verification
- Start the engine.
- Monitor the ISS parameter on the scan tool while varying the engine speed. The ISS RPM should vary as the engine RPM varies without any dropouts.
Circuit/System Testing
- Ignition OFF, disconnect the TCM X1 connector.
- Measure for 820-1,428 ohms between the ISS high signal circuit terminal 3 and the ISS low signal circuit terminal 26.
- Measure for more than 10 ohms of resistance between the ISS high signal circuit terminal 3 and ground.
- Measure for more than 10 ohms of resistance between the ISS low signal circuit terminal 26 and ground.
- Connect the TCM connector. Disconnect the transmission 20-way connector.
- Ignition ON, test the ISS high signal circuit terminal 3 for a short to voltage.
| ⇒ | If greater than the specified range test the ISS high signal and the ISS low signal circuits for an open/high resistance. If the circuits/connections test normal, replace the input shaft speed sensor. |
| ⇒ | If less than 820 ohms test the ISS high signal and the ISS low signal circuits for a shorted together condition. If the circuits/connections test normal, replace the input shaft speed sensor. |
| ⇒ | If less than the specified range, repair the short to ground. |
| ⇒ | If less than the specified range, repair the short to ground. |
| ⇒ | If all circuits test normal, test or replace the internal transmission wiring harness or the ISS sensor. |
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
| • | Control Module References for ECM replacement, setup, and programming |
