Circuit Description
The automatic transmission input shaft speed sensor (AT ISS) is a permanent magnet generator. The AT ISS mounts in the transmission case facing the drive sprocket of the input shaft. As the drive sprocket rotates, an AC voltage is induced and transmitted to the transmission control module (TCM). The TCM converts the AC voltage into a digital signal. The TCM uses the input shaft speed signal to determine shift timing, torque converter clutch slip speed and gear ratio.
If the TCM detects an unrealistic change in RPM from the AT ISS, then DTC P0716 sets. DTC P0716 is a type B DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0716 Input Speed Sensor Performance
Conditions for Running the DTC
| • | No MAF DTCs P0101, P0102 or P0103. |
| • | No MAP DTCs P0106, P0107 or P0108. |
| • | No TP DTCs P0121, P0122 or P0123. |
| • | No OSS DTCs P0722 or P0723. |
| • | No AT ISS DTC P0717. |
| • | No shift solenoid valve performance DTCs P0751 or P0752. |
| • | No shift solenoid valve electrical DTCs P0973 or P0974. |
| • | The engine run time is greater than 5 seconds. |
| • | The TP sensor is 8 percent or greater. |
| • | The vehicle speed is 16 km/h (10 mph) or greater. |
| • | The transmission input shaft speed is 1,050 RPM or greater for 2 seconds. |
| • | The transmission input shaft speed has not changed by 500 RPM or less for 2 seconds. |
| • | The engine torque is between 50-1492 N·m (37-1100 lb ft). |
Conditions for Setting the DTC
The transmission input shaft speed drops by 1,000 RPM or greater for 3.25 seconds.
Action Taken When the DTC Sets
| • | The TCM requests the engine control module (ECM) to illuminate the malfunction indicator lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met. |
| • | The TCM commands maximum line pressure. |
| • | The TCM freezes transmission adaptive functions. |
| • | The TCM calculates input shaft speed from vehicle speed and commanded gear. |
| • | 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 and 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 P0716 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. |
| • | The TCM clears the DIC message when the condition no longer exists. |
| • | 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. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
-
This step tests the AT ISS for correct resistance.
-
This step tests the AT ISS high signal circuit for being shorted to another circuit within the transmission.
Step | Action | Values | 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 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 | ||||
Refer to Automatic Transmission Inline 20-Way Connector End View . Does the resistance measure within the specified range? | 1,260-1,872 ohms | Go to Step 7 | Go to Step 4 | |||||
4 | Does the resistance measure greater than the specified value? | 1,872 ohms | Go to Step 5 | Go to Step 6 | ||||
5 |
Refer to Circuit Testing . 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 AT ISS for being shorted together between the AT inline 20-way connector and the AT ISS. Refer to Circuit Testing . Did you find the condition? | -- | Go to Step 11 | Go to Step 12 | ||||
7 | Measure the resistance between terminal S of the J 44152 and ground. Refer to Automatic Transmission Inline 20-Way Connector End View . Does the resistance measure less than the specified value? | 10M ohms | Go to Step 11 | Go to Step 8 | ||||
Measure the resistance between terminal S and all other terminals, except terminal V, of the J 44152 . Refer to Automatic Transmission Inline 20-Way Connector End View . Does the resistance measure between terminal S and any other terminal, except terminal V, less than the specified value? | 10M ohms | Go to Step 11 | Go to Step 9 | |||||
9 | Test the high signal circuit of the AT ISS for a high resistance, an open, a short to ground or a short to voltage between the TCM connector and the AT inline 20-way connector. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 10 | ||||
10 | Test the low signal circuit of the AT ISS for a high resistance or an open between the TCM connector and the AT inline 20-way connector. Refer to Testing for Continuity and Wiring Repairs . Did you find and correct the condition? | -- | Go to Step 14 | Go to Step 13 | ||||
11 |
Important: The automatic transmission wiring harness consists of 2 separate harnesses, the Automatic Transmission Wiring Harness Assembly and the Automatic Transmission Wiring Extension Harness Assembly. In order to avoid the unnecessary replacement of parts, only replace the Automatic Transmission Wiring Harness Assembly. Replace the automatic transmission wiring harness. Refer to Input Speed Sensor and Wiring Harness Removal in the 4T80-E section of the Transmission Unit Repair Manual. Did you complete the replacement? | -- | Go to Step 14 | -- | ||||
12 | Replace the AT ISS. Refer to Input Speed Sensor and Wiring Harness Removal in the 4T80-E section of the Transmission Unit Repair Manual. Did you complete the replacement? | -- | Go to Step 14 | -- | ||||
13 | Replace the TCM. Refer to Control Module References . 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 |
