The automatic transmission input (shaft) speed (AT ISS) sensor provides transmission input speed to the vehicle control module (VCM). The AT 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 an unreasonably large change in the input speed, in a very short period of time, then DTC P0716 sets. DTC P0716 is a type C DTC. For California emissions vehicles, DTC P0716 is a type B DTC.
• | No throttle position (TP) sensor DTCs P0121, P0122 or P0123. |
• | No OSS DTC P0502 or P0503. |
• | No AT ISS DTC P0717. |
• | No shift solenoid DTC P0751 or P0753. |
• | The TP is greater than 10%. |
• | The vehicle speed is greater than 25 mph. |
• | The engine is running greater than 475 RPM for more than 7 seconds. |
• | The transmission is not in PARK or NEUTRAL. |
• | The input speed varies by 1200 RPM for greater than 5 seconds. |
• | For California emission vehicles only, the VCM illuminates the malfunction indicator lamp (MIL). |
• | The VCM commands maximum line pressure. |
• | The VCM freezes shift adapts. |
• | The VCM stores DTC P0716 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 AT 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 AT ISS sensor.
This step tests for proper AT 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 5.0/5.7L or Powertrain On Board Diagnostic (OBD) System Check 7.4L | |||||
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 VCM. Is the Scan Tool Transmission ISS more than 800 RPM? | -- | Go to Diagnostic Aids | ||||||
3 |
Is the sensor resistance within the specified value? | 1042-2088ohms | ||||||
4 | Inspect circuit 1230 (RED/BLK) for an open or a short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Was an open or short to ground condition found? | -- | ||||||
5 | Inspect circuit 1231 (BLU/WHT) for an open. Refer to General Electrical Diagnosis in Wiring Systems. Was an open condition found? | -- | ||||||
Refer to Automatic Transmission Components. Is the voltage above the specified value? | 0.5 volts AC | Go to Diagnostic Aids | ||||||
7 | Repair the open or short to ground in circuit 1230 (RED/BLK). Refer to Wiring Repairs in Wiring Systems. Was the condition corrected? | -- | -- | |||||
8 | Repair the open in circuit 1231 (BLU/WHT). Refer to Wiring Repairs in Wiring Systems. Was the open condition corrected? | -- | -- | |||||
9 | Replace the ISS sensor. Refer to Vehicle Speed Sensor Replacement . Is the replacement complete? | -- | -- | |||||
10 |
Was the condition found? | -- | ||||||
11 | Replace the VCM. Refer to VCM Replacement/Programming (5.7L) or VCM Replacement/Programming (7.4L) in Engine Controls. Is the replacement complete? | -- | -- | |||||
12 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |
The automatic transmission input (shaft) speed sensor (AT ISS) provides transmission input speed to the powertrain control module (PCM). The AT 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 an unrealistically large change in input speed, then DTC P0716 sets. DTC P0716 is a type B DTC.
• | No AT ISS sensor DTC P0717. |
• | No OSS sensor DTCs P0502 or P0503. |
• | System voltage is 8.0-18.0. volts. |
• | Engine speed is greater than 475 RPM for greater than 7 seconds. |
• | The APP angle is greater than 15%. |
• | The vehicle speed is greater than 32 km/h (20 mph). |
The AT ISS varies by more than 1,200 RPM within 4.0 seconds.
• | The PCM illuminates the malfunction indicator lamp (MIL). |
• | The PCM commands maximum line pressure. |
• | The PCM freezes shift adapts. |
• | The PCM stores DTC P0716 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. |
• | You may have to drive the vehicle in order to experience a fault. |
• | First diagnose and clear any engine DTCs 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 of the AT ISS sensor.
This step tests for proper AT ISS sensor circuit operation up to the PCM connections. You remove the fuel solenoid fuse in order to eliminate a flooding condition during this step.
This step tests for a short to ground in the AT ISS sensor circuit.
Step | Action | Value(s) | Yes | No | ||||
---|---|---|---|---|---|---|---|---|
1 | Did you perform the Powertrain Diagnostic System Check? | -- | ||||||
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 PCM. Does the Transmission ISS RPM change by more than 1200 RPM at steady engine speed? | -- | Go to Diagnostic Aids | |||||
3 |
Is the AT ISS sensor resistance within the specified value? | 1042-2088ohms | ||||||
Is the J 39200 DMM voltage steady? | Greater than 10.0 volts AC | |||||||
5 |
Is either voltage reading greater than the specified value? | 10.5 volts DC | ||||||
6 |
Refer to General Electrical Diagnosis in Wiring Systems. Was the condition found? | -- | ||||||
7 | Repair the short to power in circuits 1230 (RED/BLK) and/or 1231 (DK BLU/WHT). Is the repair complete? | -- | -- | |||||
Refer to Automatic Transmission Components. Is the voltage greater than the specified value and steady? | 0.4 volts AC | |||||||
9 | With the J 39200 DMM measure the resistance between terminals D1 and D11 of the PCM connector C1. Is the circuit resistance within the specified value? | 1042-2088ohms | ||||||
Is either resistance less than the specified value? | 50kohms | Go to Diagnostic Aids | ||||||
11 | Inspect circuits 1230 (RED/BLK) and 1231 (DK BLU/WHT) for short to ground. Refer to General Electrical Diagnosis in Wiring Systems. Was the condition corrected? | -- | -- | |||||
12 | Is the resistance reading from Step 9 less than the specified value? | 1042-2088ohms | ||||||
13 | Repair circuits 1230 (RED/BLK) and 1231 (DK BLU/WHT) for a short together. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | -- | |||||
14 |
Refer to General Electrical Diagnosis in Wiring Systems. Was the condition corrected? | -- | -- | |||||
15 | Replace the AT ISS sensor. Refer to Vehicle Speed Sensor Replacement . Is the replacement complete? | -- | -- | |||||
16 | Inspect the PCM pins and connector terminals for corrosion or reduced terminal tension. Was the condition found? | -- | ||||||
17 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | -- | |||||
18 | Perform the following procedure in order to verify the repair:
Important: Failure to clear codes first may cause poor engine performance and high idle at start up.
Has the test run and passed? | -- | System OK |