For 1990-2009 cars
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Control Module References

### Circuit Description

The automatic transmission input speed sensor (ISS) provides transmission input speed to the transmission control module (TCM). The ISS is a permanent magnet generator. The sensor mounts into the transmission case and maintains a slight air gap between the sensor and the drive sprocket. The ISS produces an AC voltage as the drive sprocket rotor teeth pass through the magnetic field of the sensor. The AC voltage level increases as the turbine shaft speed increases. The TCM converts the AC voltage into a digital signal. The TCM determines actual turbine speed using the digital signal. The TCM uses the input speed to calculate torque converter slip speed, and gear ratios.

When the TCM detects a low input speed and the vehicle has a large vehicle speed, then DTC P0717 sets. DTC P0717 is a type B DTC.

### DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC P0717 Input Speed Sensor Circuit Low Voltage

### Conditions for Running the DTC

• | No MAP DTCs P0107 or P0108.

• | No ISS DTC P0717.

• | No OSS DTCs P0722 or P0723.

• | The engine is running for 5 seconds.

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

• | The engine torque is greater than 50 N·m (37 lb ft).

### Conditions for Setting the DTC

The input speed is less than 100 RPM for 4.5 seconds.

### Action Taken When the DTC Sets

• | The TCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.

• | The TCM commands maximum line pressure.

• | The TCM freezes transmission adaptive functions.

• | The TCM calculates the ISS from engine speed and gear ratio.

• | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Freeze Frame and Failure Records.

• | The TCM stores DTC P0717 in TCM history during the second consecutive trip in which the Conditions for Setting the DTC are met.

### Conditions for Clearing the MIL/DTC

• | The TCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.

• | A scan tool can clear the MIL/DTC.

• | The TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.

• | The TCM cancels the DTC default actions when the ignition switch is OFF long enough in order to power down the TCM.

### Diagnostic Aids

Ensure the wiring harness is not stretched too tightly or other components are pressing on the connector body. Also, inspect for proper clearance to any other components and wiring. Refer to Testing for Intermittent Conditions and Poor Connections .

### Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. This step tests the ISS for correct resistance.

2. This step tests the ISS high signal circuit for being shorted to another circuit within the transmission.

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the Diagnostic System Check - Vehicle? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle
2 |

1. Install a scan tool.
2. Turn ON the ignition, with the engine OFF.

Important: Before clearing the DTC, use the scan tool in order to record the Freeze Frame and Failure Records. Using the Clear Info function erases the Freeze Frame and Failure Records from the TCM.

3. Record the DTC Freeze Frame and Failure Records.
4. Clear the DTC.
5. Start the engine.
6. Select Transmission ISS on the scan tool.

Is the transmission input speed greater than the specified value?

500 RPM

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3 |

1. Turn OFF the ignition.
2. Disconnect the AT inline 20-way connector. Additional DTCs may set.
3. Install the J 44152 jumper harness (20 pins) on the transmission side of the AT inline 20-way connector.
4. Using the DMM and the J 35616 GM-approved terminal test kit, measure the resistance between the ISS high signal and the ISS low signal circuits of the J 44152 .

Refer to Automatic Transmission Inline 20-Way Connector End View .

Is the resistance within the specified range?

615-835 ohms

Go to Step 7

Go to Step 4

4 | Is the resistance greater than the specified value? | 835 ohms | Go to Step 5 | Go to Step 6
5 |

1. Test the high signal circuit of the ISS for a high resistance or an open between the AT inline 20-way connector and the ISS.
2. Test the low signal circuit of the ISS for a high resistance or an open between the AT inline 20-way connector and the ISS.

Refer to Testing for Continuity .

Did you find a high resistance or open condition?

--

Go to Step 11

Go to Step 12

6 | Test the high signal circuit and the low signal circuit of the ISS for being shorted together between the AT inline 20-way connector and the ISS. Refer to Circuit Testing . Did you find the condition? | -- | Go to Step 11 | Go to Step 12
7 | Measure the resistance between the ISS high signal circuit of the J 44152 and ground. Refer to Automatic Transmission Inline 20-Way Connector End View . Is the resistance less than the specified value? | 1,000 ohms | Go to Step 11 | Go to Step 8
8 | Measure the resistance between the ISS high signal circuit and all other terminals except the ISS low signal circuit of the J 44152 . Refer to Automatic Transmission Inline 20-Way Connector End View . Is the resistance between less than the specified value? | 1,000 ohms | Go to Step 11 | Go to Step 9
9 | Test the high signal circuit of the ISS for a high resistance, an open, a short to ground or a short to voltage between the TCM connector and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs . Did you find and correct a condition? | -- | Go to Step 14 | Go to Step 10
10 | Test the low signal circuit of the ISS for a high resistance or an open between the TCM connector and the AT inline 20-way connector. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct a condition? | -- | Go to Step 14 | Go to Step 13
11 | Replace the automatic transmission wiring harness. Refer to Wiring Harness Replacement . Did you complete the replacement? | -- | Go to Step 14 | --
12 | Replace the ISS. Refer to Input Speed Sensor Removal . Did you complete the replacement? | -- | Go to Step 14 | --
13 | Replace the TCM. Refer to Control Module References for replacement, setup, and programming. Did you complete the replacement? | -- | Go to Step 14 | --
14 | Perform the following procedure in order to verify the repair:

1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle under the following conditions:

• | Start the engine.

• | The transmission input speed must be greater than 500 RPM for 3 seconds.

4. Select Specific DTC.
5. Enter DTC P0717.

Has the test run and passed?

--

Go to Step 15

Go to Step 2

15 | With the scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? | -- | Go to Diagnostic Trouble Code (DTC) List - Vehicle | System OK