The automatic transmission input (shaft) speed (A/T ISS) sensor provides transmission input speed to the vehicle control module (VCM). The A/T ISS sensor is a permanent magnet (PM) generator. The sensor mounts into the transmission case and maintains a slight air gap between the sensor and the forward clutch housing. The PM generator produces an AC voltage as the forward clutch housing rotor teeth pass through the sensor's magnetic field. The AC voltage level increases as the turbine shaft speed increases. The VCM converts the AC voltage into a digital signal. The VCM determines actual turbine speed using the digital signal. The VCM uses the input speed to calculate torque converter slip speed, and gear ratios.
When the VCM detects a low or no input speed during high vehicle and high engine speeds, then DTC P0717 sets. DTC P0717 is a type D DTC. For California emissions vehicles, DTC P0717 is a type B DTC.
• | No OSS DTC P0502 or P0503. |
• | No TFP manual valve position switch DTC P1810. |
• | TFP manual valve position switch is not PARK or NEUTRAL. |
• | The vehicle speed is greater than 12 mph. |
• | The engine runs greater than 475 RPM for at least 7 seconds, and not in fuel cutoff. |
The measured input speed is less than 50 RPM for at least 5.0 seconds.
• | For California emissions only, the VCM illuminates the malfunction indicator lamp (MIL). |
• | The VCM defaults the transmission to maximum line pressure. |
• | The VCM freezes shift adapts. |
• | The VCM stores DTC P0717 in VCM history. |
• | For California emissions, the VCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes. |
• | A scan tool clears the DTC from VCM history. |
• | For California emissions, the VCM clears the DTC from VCM history if the vehicle completes 40 consecutive warm-up cycles without an emission related diagnostic fault occurring. |
• | For Federal emissions, the VCM clears the DTC from VCM history if the vehicle completes 40 consecutive warm-up cycles without a non-emission related diagnostic fault occurring. |
• | The VCM 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 VCM. |
• | Inspect the wiring at the VCM, the OSS connector and all other circuit connecting points for the following: |
- | A backed out terminal |
- | A damaged terminal |
- | Reduced terminal tension |
- | A chafed wire |
- | A broken wire inside the insulation |
- | Moisture intrusion |
- | Corrosion |
- | The A/T ISS sensor harness being near the DIS components or the ignition wires. |
• | When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. |
• | First diagnose and clear any engine DTCs or TP sensor codes that are present. Then inspect for any transmission DTCs that may have reset. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests for proper operation to the A/T ISS Sensor.
This step tests for proper A/T ISS circuit operation up to the VCM connections. Remove the fuel pump relay in order to eliminate a flooding condition during this step.
Step | Action | Value(s) | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain Diagnostic System Check? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check (5.7L) or Powertrain On Board Diagnostic (OBD) System Check (7.4L) Section 6E3 | |||||
Important: Before clearing the DTC, use the Scan Tool in order to record the Freeze Frame and Failure Records for reference. The Clear Info function will erase the data. With the drive wheels rotating, does the Scan Tool Transmission ISS increase with the drive wheel speed? | -- | Go to Intermittent Conditions (5.7L or Intermittent Conditions (7.4L) in Engine Controls | ||||||
3 |
Does the resistance measure within the specified range? | 1377-3355 ohms | ||||||
4 | Measure the resistance from terminal C3-7 to ground. Does the resistance measure greater than the specified value? | 50 K ohms | ||||||
Refer to General Electrical Diagnosis in Wiring Systems. Did you find and correct the condition? | -- | |||||||
6 |
Does the resistance measure within the specified range? | 1377-3355 ohms | ||||||
7 | Was the resistance measured in Step 3 greater than the specified value? | 3355 ohms | ||||||
8 |
Refer to General Electrical Diagnosis in Wiring Systems. Did you find and correct the condition? | -- | -- | |||||
9 |
Refer to General Electrical Diagnosis in Wiring Systems. Did you find and correct the condition? | -- | -- | |||||
10 | Test the high circuit (CKT 1230) and the low circuit (CKT 1231) of the ISS assembly for a short together. Refer to General Electrical Diagnosis in Wiring Systems. Did you find and correct the condition? | -- | -- | |||||
11 | Replace the ISS assembly. Refer to Vehicle Speed Sensor Replacement . Did you complete the replacement? | -- | -- | |||||
12 | Replace the VCM. Refer to VCM Replacement/Programming (5.7L) or VCM Replacement/Programming (7.4L) in Engine Controls. Did you complete the replacement? | -- | -- | |||||
13 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |
The automatic transmission input (shaft) speed (A/T ISS) sensor provides transmission input speed to the powertrain control module (PCM). The A/T ISS sensor is a permanent magnet (PM) generator. The sensor mounts into the transmission case and maintains a slight air gap between the sensor and the forward clutch housing. The PM generator produces an AC voltage as the forward clutch housing rotor teeth pass through the sensor's magnetic field. The AC voltage level increases as the turbine shaft speed increases. The PCM converts the AC voltage into a digital signal. The PCM determines actual turbine speed using the digital signal. The PCM uses the input speed to calculate torque converter slip speed, and gear ratios.
When the PCM detects a low or no input speed during high vehicle and high engine speeds, then DTC P0717 sets. DTC P0717 is a type B DTC.
• | No OSS sensor DTCs P0722 or P0723. |
• | No TFP manual valve position switch DTC P1810. |
• | TFP manual valve position switch is not in PARK or NEUTRAL. |
• | The vehicle speed is greater than 40 km/h (25 mph). |
• | System voltage is 8.0-18.0 volts. |
• | The engine runs greater than 475 RPM for 7 seconds. |
The A/T ISS is less than 100 RPM for at least 5 seconds.
• | The PCM illuminates the malfunction indicator lamp (MIL). |
• | The PCM defaults the transmission to maximum line pressure. |
• | The PCM freezes shift adapts. |
• | The PCM stores DTC P0717 in PCM history. |
• | For Federal and California emissions, 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. |
• | For Federal and California emissions, the PCM clears the DTC from PCM history if the vehicle completes 40 consecutive warm-up cycles without an emission related diagnostic fault occurring. |
• | For vehicles equal to or greater than 15,000 lbs GVW, the PCM clears the DTC from PCM history if the vehicle completes 40 consecutive warm-up cycles without a non-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. |
• | Inspect the wiring at the PCM, the transmission connector and all other circuit connecting points 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 |
- | Corrosion |
• | When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. |
• | First, diagnose and clear any engine DTCs that are present. Then, inspect for any transmission DTCs that may have reset. If DTC P0717 and DTC P0731, P0732, P0733 or P0734 are present, diagnose DTC P0717 first. |
The numbers below refer to the step numbers on the diagnostic table.
This step tests for proper operation of the A/T ISS sensor.
This step tests for proper A/T ISS sensor and circuit operation. Remove the fuel solenoid fuse in order to eliminate a flooding condition.
Step | Action | Value(s) | Yes | No | ||||||
---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | ||||||||
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. Important: If a DTC P0731, P0732, P0733 or P0734 is also present, refer to the Diagnostic Aids. Is the resistance within the specified value? | 1042-2088ohms | |||||||||
3 |
Is the DMM voltage greater than the specified value? | 3.0 volts AC | ||||||||
Refer to Automatic Transmission Components . Is the voltage greater than the specified value? | 0.4 volts AC | |||||||||
5 | Inspect circuit 1230 (RED/BLK) for an open, a short to B+, or a short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Was the condition found? | -- | ||||||||
6 | Inspect circuit 1231 (DK BLU/WHT) for a short to B+, or an open. Refer to General Electrical Diagnosis in Wiring Systems. Was the condition found? | -- | Go to Diagnostic Aids | |||||||
7 | Repair the condition in circuit 1230 (RED/BLK). Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |||||||
8 | Repair the condition in circuit 1231 (DK BLU/WHT). Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |||||||
9 | Replace the input shaft speed sensor. Refer to Vehicle Speed Sensor Replacement. Is the replacement complete? | -- | -- | |||||||
10 | Inspect the PCM connector pins and the C1 terminals. Was the condition found? | -- | ||||||||
11 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | -- | |||||||
12 | Perform the following procedure in order to verify the repair:
Important: Failure to clear codes before continuing may cause poor engine performance and high idle at start up.
Has the test run and passed? | -- | System OK |