Circuit Description
The Automatic Transmission Input (Shaft) Speed Sensor (A/T ISS) is a permanent magnet with a coil of wire wound around it. The A/T ISS mounts in the transmission case facing the drive sprocket of the input shaft. An air gap of 1.14-2.77 mm (0.045-0.109 in) between the sensor and drive sprocket must be maintained in order to transmit an accurate AC voltage. Sensor voltage varies from 0.5 volts AC at 100 RPM to more than 100 volts at 8000 RPM. This diagnostic monitors the A/T ISS circuit. The circuit may be functional but not in the normal operating range. This diagnostic indicates stuck, erratic, or intermittent values, indicating poor performance of the system. The A/T ISS has a resistance value of 1300-1950 ohms.
When the Powertrain Control Module (PCM) detects an unrealistically large change in data from the A/T Input (Shaft) Speed Sensor, then DTC P0716 sets. DTC P0716 is a Type B DTC.
Conditions for Setting the DTC
| • | No TP DTCs P0121, P0122 or P0123. |
| • | No VSS DTCs P0502 or P0503. |
| • | No A/T ISS DTC P0717. |
| • | No 1-2 shift solenoid valve performance DTC P0751. |
| • | No 1-2 shift solenoid valve electrical DTC P0753. |
| • | No 2-3 shift solenoid valve performance DTC P0756. |
| • | No 2-3 shift solenoid valve electrical DTC P0758. |
| • | The engine run time is greater than 5 seconds. |
| • | The engine is not in fuel cut off |
| • | The vehicle speed is greater than 11 km/h (7 mph). |
| • | The throttle angle is greater than 12.8°. |
| • | Changes to the input speed by 1000 RPM or greater in 0.075 seconds 10 times in 10 seconds |
Action Taken When the DTC Sets
| • | The PCM illuminates the Malfunction Indicator Lamp (MIL). |
| • | SERVICE ENGINE SOON displays on the Driver Information Center (DIC). |
| • | The PCM commands default line pressure. |
| • | The PCM inhibits TCC engagement. |
| • | The PCM disables steady state adapts. |
| • | The PCM disables upshift adapts. |
| • | The PCM disables garage shift adapts. |
| • | The PCM inhibits garage shift pressure calculations. |
| • | The PCM calculates input speed from vehicle speed and commanded gear. |
| • | DTC P0716 is stored in the PCM history. |
Conditions for Clearing the MIL/DTC
| • | The PCM turns OFF the MIL after three consecutive trips without a failure reported. |
| • | A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported. |
| • | The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM. |
Diagnostic Aids
| • | Ensure that the Engine Wiring Harness is not located near spark plug wires or DIS coils. |
| • | Inspect the wiring for poor electrical connections at the PCM, the transmission 20-way connector, the A/T ISS 2-way connector and all other circuit connecting points for the following conditions: |
| - | A bent terminal |
| - | A backed out terminal |
| - | A damaged terminal |
| - | Poor terminal tension |
| - | A chafed wire |
| - | A broken wire inside the insulation |
| - | Moisture intrusion |
| • | When diagnosing for an intermittent short or open, massage the wiring harness while watching the test equipment for a change. |
Test Description
The numbers below refer to the step numbers on the diagnostic table.
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This step verifies that the DTC is set and the scan tool displays the Automatic Transmission Input (Shaft) Speed sensor RPM.
-
This step inspects circuit 1230 and circuit 1231 for an AC voltage.
-
This step verifies that circuit 1231 is not open.
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This step measures the resistance value of the Automatic Transmission Input (Shaft) Speed sensor and circuitry. A Digital Multimeter, set to measure ohms, must display a value between 1300-1950 ohms.
-
This step tests for a resistance of less than 100 ohms. A resistance of less than 100 ohms indicates a possible short to ground in circuit 1230 or 1231.
Step | Action | Value(s) | Yes | No | ||||
|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to A Powertrain On Board Diagnostic (OBD) System Check | |||||
Important: Before clearing the DTC(s), use the scan tool in order to record the Freeze Frame and Failure Records for reference. Using the Clear Info function will erase the stored Freeze Frame and Failure Records from the PCM. Does the scan tool display a transmission input speed greater than the specified value? | 100 RPM | Go to Diagnostic Aids | ||||||
Does the DMM display an AC voltage greater than the specified value? | 0.5 V AC | |||||||
4 |
Does the DMM display a DC voltage greater than the specified value? | 300 mV DC | ||||||
5 | Inspect circuit 1230 of the Engine Wiring Harness for an open or short to ground. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | ||||||
Connect a test lamp from terminal E to terminal V of the Engine Wiring Harness. Does the test lamp light? | -- | |||||||
7 | Inspect circuit 1231 of the Engine Wiring Harness for an open. Refer to Electrical Diagnosis, Section 8. Did you find and correct the condition? | -- | ||||||
Is the resistance value within the specified range? | 1300-1950 ohms | |||||||
9 | Is the resistance greater than the specified value? | 1950 ohms | ||||||
10 |
Refer to Electrical Diagnosis, Section 8. Did you find the condition? | -- | ||||||
11 | Is the resistance less than the specified value? | 1300 ohms | -- | |||||
12 | Inspect circuits 1230 and 1231 of the Automatic Transmission Wiring Harness for a short together. Refer to Electrical Diagnosis, Section 8. Did you find the condition? | -- | ||||||
Measure the resistance from terminal A to the transmission case. Is the resistance less than the specified value? | 100 ohms | -- | ||||||
14 |
Refer to Electrical Diagnosis, Section 8. Did you find the condition? | -- | ||||||
15 | Replace the Automatic Transmission Wiring Harness. Refer to A/T Wiring Harness Replacement in On-Vehicle Service. Is the replacement complete? | -- | -- | |||||
16 | Replace the Automatic Transmission Input (Shaft) Speed sensor. Refer to A/T ISS Replacement in On-Vehicle Service. Is the replacement complete? | -- | -- | |||||
17 | Replace the PCM. Refer to PCM Replacement/Programming , Section 6. Is the replacement complete? | -- | -- | |||||
18 | In order to verify your repair, perform the following procedure:
Has the test run and passed? | -- | System OK |
