GM Service Manual Online
For 1990-2009 cars only

Object Number: 1492404  Size: MF
Master Electrical Component List
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice
Control Module References

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 powertrain control module (PCM). The PCM converts the AC voltage into a digital signal. The PCM uses the input shaft speed signal to determine shift timing, torque converter clutch slip speed and gear ratio.

If the PCM 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 TP DTCs P0121, P0122 or P0123.
    • No VSS DTCs P0502 or P0503.
    • No AT ISS DTC P0717.
    • No shift solenoid valve performance DTCs P0751, P0752, P0756, or P0757.
    • No shift solenoid valve electrical DTCs P0973, P0974, P0976, or P0977.
    • The engine run time is greater than 5 seconds.
    • The TP angle is 12 percent or greater.
    • The vehicle speed is 16 km/h (10 mph) or greater.
    • The transmission input shaft speed is greater than 1,050 RPM for at least 2 seconds.
    • The transmission input shaft speed has not increased by 500 RPM or greater for at least 2 seconds.

Conditions for Setting the DTC

The transmission input shaft speed drops by 1,000 RPM or greater for at least 1 second.

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.
    • The PCM commands maximum line pressure.
    • The PCM inhibits TCC engagement.
    • The PCM freezes transmission adaptive functions.
    • The PCM calculates input shaft speed from vehicle speed and commanded gear.
    • The PCM records the operating conditions when the Conditions for Setting the DTC are met. The PCM stores this information as Freeze Frame and Failure Records.
    • The PCM stores DTC P0716 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 can clear the MIL/DTC.
    • 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 ignition switch is OFF long enough in order to power down the PCM.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. This step tests the AT ISS for correct resistance.

  2. This step tests the AT ISS high signal circuit for being shorted to another circuit within the transmission.

DTC P0716

Step

Action

Values

Yes

No

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. 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 PCM.

  4. Record the DTC Freeze Frame and Failure Records.
  5. Clear the DTC.
  6. Start the engine.
  7. Select Transmission ISS on the scan tool.

Is the transmission input speed greater than the specified value?

500 RPM

Go to Intermittent Conditions in Engine Controls

Go to Step 3

3

  1. Turn OFF the ignition.
  2. Disconnect the AT inline 20-way connector. Additional DTCs may set.
  3. Install the J 44152 Jumper Harness on the transmission side of the AT inline 20-way connector.
  4. Using the DMM and the J 35616 GM Terminal Test Kit, measure the resistance between terminals S and V of the J 44152 .
  5. 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

  1. Test the high signal circuit of the AT ISS for a high resistance or an open between the AT inline 20-way connector and the AT ISS.
  2. Test the low signal circuit of the AT ISS for a high resistance or an open between the AT inline 20-way connector and the AT ISS.
  3. Refer to Circuit Testing in Wiring Systems.

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 in Wiring Systems.

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

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 PCM connector C3 and the AT inline 20-way connector.

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

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 PCM connector C3 and the AT inline 20-way connector.

Refer to Testing for Continuity and Wiring Repairs in Wiring Systems.

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 PCM.

Refer to Control Module References in Computer/Integrating Systems.

Did you complete the replacement?

--

Go to Step 14

--

14

Perform the following procedure in order to verify the repair:

  1. Select DTC.
  2. Select Clear Info.
  3. Operate the vehicle under the following conditions:
  4. • Road test the vehicle.
    • The transmission input shaft speed must be greater than 550 RPM without a speed change greater than 500 RPM for 2 seconds.
  5. Select Specific DTC.
  6. Enter DTC P0716.

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?

--

Go to Diagnostic Trouble Code (DTC) List - Vehicle in Vehicle DTC Information

System OK