The Automatic Transmission Input Shaft Speed (A/T ISS) Sensor consists of a permanent magnet surrounded by a coil of wire. The rotation of the forward clutch housing induces an AC voltage in the circuit. The signal voltage and frequency vary directly with the forward clutch rotational speed.
When the Powertrain Control Module (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 Val. Position Sw. DTC P1810 |
• | The vehicle speed is greater than 20 mph. |
• | The engine runs greater than 475 RPM 7 seconds. |
• | The A/T ISS is less than 50 RPM for at least 5 seconds. |
• | The PCM defaults the transmission to maximum line pressure. |
• | The PCM freezes shift adapts. |
• | The PCM illuminates the Malfunction Indicator Lamp (MIL). |
• | Inspect the wiring for poor electrical connections at the PCM Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following problems: |
- | A bent terminal |
- | A backed out terminal |
- | A damaged terminal |
- | Poor terminal tension |
- | A chafed wire |
- | A broken wire inside the insulation |
• | 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 a DTC P0717 and a DTC P1871 are both 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 Sol. 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 for reference. The Clear Info function will erase the data. Important: If a DTC P1871 is also present, refer to the Diagnostic Aids. Is the voltage greater than the specified value? | 0.5 volts AC | |||||||
3 | Inspect circuit 1230 for an open or a short to ground. Refer to Electrical Diagnosis, Section 8. Did you find a problem? | -- | ||||||
4 | Inspect circuit 1231 for an open. Refer to Electrical Diagnosis, Section 8. Did you find a problem? | -- | ||||||
Refer to Automatic Transmission Components . Is the voltage greater than the specified value? | 0.5 volts AC | Refer to Diagnostic Aids | ||||||
6 | Repair the open or short to ground in circuit 1230. Did you correct the problem? | -- | -- | |||||
7 | Repair the open in circuit 1231. Did you correct the problem? | -- | -- | |||||
8 | Replace the Input Shaft Speed Sensor. Refer to Speed Sensor Replacement, in On-Vehicle Service. Is the replacement complete? | -- | -- | |||||
9 | Inspect the PCM pins and the C1 connector terminals. Did you find a problem? | -- | ||||||
10 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming , Section 6. Is the replacement complete? | -- | -- | |||||
11 | In order to verify your repair, perform the following procedure:
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 |
The Automatic Transmission Input Shaft Speed (A/T ISS) Sensor consists of a permanent magnet surrounded by a coil of wire. The rotation of the forward clutch housing induces an AC voltage in the circuit. The signal voltage and frequency vary directly with the forward clutch rotational speed.
When the Vehicle Control Module (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 |
• | No TFP Val. Position Sw. DTC P1810 |
• | The vehicle speed is greater than 25 mph. |
• | The engine runs greater than 475 RPM for at least 5 seconds and not in fuel cutoff. |
• | The measured input speed is less than 50 RPM for at least 7 seconds. |
• | The VCM defaults the transmission to D2 pressure. |
• | The VCM freezes shift adapts. |
• | For California emissions only, the VCM illuminates the Malfunction Indicator Lamp (MIL). |
• | Inspect the wiring for poor electrical connections at the VCM. Inspect the wiring for poor electrical connections at the transmission 20-way connector. Look for the following problems: |
- | A bent terminal |
- | A backed out terminal |
- | A damaged terminal |
- | Poor terminal tension |
- | A chafed wire |
- | A broken wire inside the insulation |
- | 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 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 in Engine Controls | ||||||
3 |
Does the resistance measure within the specified range? | 1377-3355 Ω | ||||||
4 | Measure the resistance from terminal C3-7 to ground. Does the resistance measure greater than the specified value? | 50 K Ω | ||||||
Refer to General Electrical Diagnosis Procedures in Wiring Systems. Did you find and correct the condition? | -- | |||||||
6 |
Does the resistance measure within the specified range? | 1377-3355 Ω | ||||||
7 | Was the resistance measured in Step 3 greater than the specified value? | 3355 Ω | ||||||
8 |
Refer to General Electrical Diagnosis Procedures in Wiring Systems. Did you find and correct the condition? | -- | -- | |||||
9 |
Refer to General Electrical Diagnosis Procedures 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 Procedures 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 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 |