The automatic transmission input speed sensor (AT ISS) is a hall effect sensor. The ISS sensor mounts in the top of the transmission case. The AT ISS sensor faces the forward and direct clutch housing machined teeth surface. As the forward and direct clutch housing rotates, a square wave voltage signal is sent to the transmission control module (TCM). The number of pulses increases as the speed of the forward and direct clutch housing increases. The TCM uses the input shaft speed signal to help determine line pressure, transmission shift patterns, torque converter clutch (TCC) slip speed and gear ratio.
If the TCM detects no input shaft speed when there is vehicle speed in a drive gear range, or if the TCM detects an open or shorted AT ISS signal circuit, then DTC P0717 sets. DTC P0717 is a type A DTC.
This diagnostic procedure supports the following DTC:
DTC P0717 Input Speed Sensor Circuit Low Voltage
• | No TR Switch DTC P0705. |
• | No TFT DTCs P0711, P0712, or P0713. |
• | Not in B1 release control. |
• | Output speed x gear ratio>600 RPM. |
• | Range = D, I, or L |
• | No OSS DTC P0722. |
• | The ignition voltage is 10.5-18 volts. |
• | Trans. Protection Mode is OFF. |
• | The vehicle speed is 66 km/h (41 mph) or greater. |
• | The commanded gear is 2 or greater. |
• | The transmission is not shifting. |
• | If the transmission temperature is greater than 20°C (68°F), and the TR Switch has been DRIVE for 2.5 seconds or greater. |
• | If the transmission temperature is 0-20°C (32-68°F), and the TR Switch has been DRIVE for 10 seconds or greater. |
• | If the transmission temperature is less than 0°C (32°F), and the TR Switch has been DRIVE for 3 minutes or greater. |
• | The ignition voltage is 10.5-18 volts. |
• | Trans. Protection Mode is OFF. |
• | The engine is running. |
The TCM does not detect any pulses from the ISS and there are 3,000 pulses from the OSS.
The ISS signal circuit is open or shorted for 30 seconds or greater.
• | The TCM requests the TCM to illuminate the malfunction indicator lamp (MIL). |
• | The TCM turns the Trans. Protection Mode ON. When the Trans. Protection Mode is ON, the following conditions occur: |
- | The transmission will operate in 5th gear when the transmission is shifted into D or I range and 2nd gear when shifted into L range. |
- | The line pressure is at maximum. |
- | The torque converter clutch (TCC) is disabled. |
- | The TCM freezes the transmission adaptive functions. |
• | The TCM calculates the input speed based on the output speed. |
• | The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as a Failure Record. |
• | The TCM stores DTC P0717 in TCM history. |
• | The powertrain control module (PCM) 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 default actions when the ignition is OFF long enough in order to power down the TCM. |
Step | Action | Values | Yes | No | ||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|
1 | Did you perform the Diagnostic System Check - Vehicle in Vehicle DTC Information? | -- | Go to Step 2 | Go to Diagnostic System Check - Vehicle in Vehicle DTC Information | ||||||||
2 |
Important:
Does the scan tool display a steady input shaft speed above the specified value? | 500 RPM | Go to Intermittent Conditions in Engine Controls - 3.4L | Go to Step 3 | ||||||||
3 |
Is the voltage within the specified range? | 9-12 V | Go to Step 5 | Go to Step 4 | ||||||||
4 | Test the AT ISS high signal and ISS low signal circuit for the following conditions:
Refer to Circuit Testing and Wiring Repairs in Wiring Systems. Did you find and correct a condition? | -- | Go to Step 9 | Go to Step 8 | ||||||||
5 | Test the AT ISS low signal circuit for a short to ground. Refer to Testing for Short to Ground and Wiring Repairs in Wiring Systems. Did you find and correct a condition? | -- | Go to Step 9 | Go to Step 6 | ||||||||
6 |
Did you find and correct a condition? | -- | Go to Step 9 | Go to Step 7 | ||||||||
7 | Replace the ISS. Refer to Input Speed Sensor Replacement . Did you complete the replacement? | -- | Go to Step 9 | -- | ||||||||
8 | Replace the TCM. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming. Is the action complete? | -- | Go to Step 9 | -- | ||||||||
9 | Perform the following procedure in order to verify the repair:
Does the DTC reset? | -- | Go to Step 2 | Go to Step 10 | ||||||||
10 | 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 in Vehicle DTC Information | System OK |