Circuit Description
The automatic transmission input (shaft) speed sensor (A/T ISS) is a permanent magnet with a coil of wire wound around it. The A/T ISS mounts in the transmission case facing the drive sprocket of the input shaft. An air gap of 0.045-0.109 in. between the sensor and the drive sprocket must be maintained so that an accurate AC voltage can be transmitted. Sensor voltage varies from 0.5 volts AC at 100 RPM to more than 100 volts at 8000 RPM. The A/T ISS has a resistance value of 1300-1950 ohms.
When the PCM detects a low input speed while the vehicle and engine speeds are high, then DTC P0717 sets. DTC P0717 is a Type B DTC.
Conditions for Running the DTC
| • | No TP DTCs P0121, P0122 or P0123. |
| • | No VSS DTCs P0502 or P0503. |
| • | No TFP manual valve position switch DTC P1810. |
| • | The engine run time is greater than 5 seconds. |
| • | The engine is not in fuel cut off. |
| • | The transmission is not in PARK or NEUTRAL. |
| • | The vehicle speed is greater than 16 km/h (10 mph). |
Conditions for Setting the DTC
The input (shaft) speed is less than 50 RPM for 2 seconds.
Action Taken When the DTC Sets
| • | The PCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met. |
| • | SERVICE ENGINE SOON, SERVICE TRANSMISSION displays on the driver information center (DIC). |
| • | The PCM commands default line pressure. |
| • | The PCM inhibits TCC engagement. |
| • | The PCM freezes steady state adapts. |
| • | The PCM freezes upshift adapts. |
| • | The PCM freezes garage shift adapts. |
| • | The PCM inhibits garage shift pressure calculations. |
| • | The PCM calculates input (shaft) speed from vehicle speed and commanded gear. |
| • | The PCM stores DTC P0717 in PCM history during the second consecutive trip in which the Conditions for Setting the DTC are met. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes. |
| • | A scan tool clears the DTC from PCM history. |
| • | The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission-related diagnostic fault occurring. |
| • | The PCM cancels the DTC default actions when the fault no longer exists and the ignition switch is OFF long enough in order to power down the PCM. |
Diagnostic Aids
| • | Inspect the wiring at the PCM, the transmission 20-way connector, and the A/T ISS 2-way connector for the following conditions: |
| - | A backed out terminal |
| - | A damaged terminal |
| - | Reduced terminal tension |
| - | A chafed wire |
| - | A broken wire inside the insulation |
| - | Moisture intrusion |
| • | When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the A/T ISS for correct resistance.
-
This step verifies the wiring from the transmission 20-way connector to the PCM, and tests the ability of the A/T ISS to produce an AC current.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||
2 |
Important: Before clearing the DTCs, 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 PCM. Is the transmission input speed greater than the specified value? | 500 RPM | Go to Diagnostic Aids | |||||
Is the resistance within the specified range? | 1300-1950 ohms | |||||||
4 | Inspect circuit 1230 of the automatic transmission wiring harness for an open or short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||||||
5 | Inspect circuit 1231 of the automatic transmission wiring harness for an open or short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||||||
6 | Replace the automatic transmission wiring harness. Refer to Unit Repair. Is the replacement complete? | -- | -- | |||||
7 | Replace the A/T ISS. Refer to Unit Repair. Is the replacement complete? | -- | -- | |||||
Is the AC voltage greater than the specified value? | 0.5 V AC | |||||||
9 | Inspect circuit 1230 of the engine wiring harness for an open or short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||||||
10 | Inspect circuit 1231 of the engine wiring harness for an open or short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | -- | |||||
11 | Repair the wiring as necessary. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |||||
12 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | -- | |||||
13 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |
