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, 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 VSS DTCs P0722 or P0723. |
| • | The engine is running for 5 seconds and not in fuel cut-off. |
| • | 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 requests the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL). |
| • | The TCM commands maximum line pressure. |
| • | The TCM freezes transmission adaptive functions. |
| • | The TCM calculates a default ISS value from the engine speed and gear ratio. |
| • | The ECM records the operating conditions when the Conditions for Setting the DTC are met. The ECM stores this information as Freeze Frame and Failure Records. |
| • | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as 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 ECM turns OFF the MIL after the third consecutive drive trip in which the TCM does not send a MIL illumination request. |
| • | 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.
-
This step tests the ISS for correct resistance.
-
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 | |||||
2 |
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 both the ECM and the TCM. 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 | ||||
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 |
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 | ||||
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 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 PCM connector C2 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 PCM connector C2 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:
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? | -- | System OK |
