For 1990-2009 cars

### 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

### 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 DTC P0716.

• | No TP sensor DTC P0120.

• | No ISS DTC P0717.

• | No OSS DTCs P0722 or P0723.

• | No 1-2 Shift Solenoid Performance DTC P0752.

• | No 1-2 Shift Solenoid Electrical DTCs P0973 or P0974.

• | The engine run time is greater than 5 seconds.

• | The engine torque DTC’s.

• | 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 greater than 12 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 DTC P0717.

• | No OSS DTCs P0722 or P0723.

• | No IMS DTCs P1815, P1820, P1822, P1823, P1825 or P1826.

• | No engine torque DTC’s.

• | The engine run time is greater than 5 seconds.

• | The vehicle speed is greater than 16 km/h (10 mph).

### 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 100 RPM for 5 seconds.

### Action Taken When the DTC Sets

• | DTC P0716 and P0717 are Type B DTCs.

• | The TCM commands TCC OFF.

• | The TCM inhibits torque management.

• | Max gear inhibited in Hot Mode.

• | The TCM commands HSD1 OFF.

• | The TCM commands maximum line pressure.

• | The TCM calculates input speed from the automatic transmission output shaft speed sensor and commanded gear.

• | The TCM calculates input speed from the automatic transmission output shaft speed sensor and commanded gear.

### 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 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

Transmission Control Module Scan Tool Information

#### Special Tools

• | J 35616 GM-Approved Terminal Test Kit

• | J 45681 Jumper Harness

### Circuit/System Verification

Start the engine. With the vehicle in PARK, 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.

### Circuit/System Testing

1. Start the engine and ensure the Transmission ISS parameter on the scan tool is greater than 100 RPM.

⇒ | If the value is less than 100 RPM disconnect the AT inline 20-way connector and install the J 45681 jumper harness on the transmission side.

2. Measure the resistance between the ISS high signal circuit and the ISS low signal circuit of the J 45681 . The resistance should be between 325 and 575 ohms.

⇒ | If the value is greater than 575 ohms, test the ISS high signal circuit and the ISS low signal circuit for an open.

⇒ | If the value is less than 325 ohms, test the ISS high signal and the ISS low signal circuits for a shorted together condition.

3. Measure the resistance of the ISS high signal circuit to the transmission case. The resistance should be greater than 10K ohms.

⇒ | If the value is less than 10 ohms, replace the transmission wiring harness assembly.

4. Measure the resistance between the ISS high signal circuit and all other circuits of the J 45681 except the ISS low signal circuit. The resistance should be greater than 10K ohms.

⇒ | If the value is less than 10K ohms, replace the transmission wiring harness assembly.

5. Measure the resistance between the ISS low signal circuit and all other circuits of the J 45681 except the ISS high signal circuit. The resistance should be greater than 10K ohms.

⇒ | If the value is less than 10K ohms replace the transmission wiring harness assembly.

6. Remove the J 45681 from the transmission side and install on the engine side of the harness. Measure the resistance between the ISS high signal circuit and ground. The resistance should be greater than 10K ohms.

⇒ | If the resistance is less than 10K ohms, test the ISS high signal circuit for a short to ground.

7. Measure the resistance of the ISS high signal circuit between the TCM connector and the AT inline 20-way connector. The resistance should be less than 10 ohms.

⇒ | If the resistance is greater than 10 ohms, test the ISS high signal for an open.

8. Measure the resistance of the ISS low signal circuit between the TCM connector and the AT inline 20-way connector. The resistance should be less than 10 ohms.

⇒ | If the resistance is greater than 10 ohms, test the ISS low signal for an open.

9. Ignition ON, test the ISS high signal circuit for a short to voltage.

⇒ | If all circuit/connections test normal, test or replace the ISS.

### Component Testing

Verify the ISS resistance is between 325-575 ohms.

⇒ | If the resistance is not within the specified range, replace the ISS.

### Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.

• | Ensure that the ISS is 550 RPM or greater for 2 seconds and does not change more than 500 RPM or greater for 2 seconds.

• | Input Speed Sensor Removal and Input Speed Sensor Installation.

• | Refer to Control Module References for TCM replacement, setup, and programming.