Circuit Description
The automatic transmission input shaft speed (A/T ISS) sensor is a permanent magnet with a coil of wire wound around it. The A/T ISS mounts in the case cover facing the drive sprocket of the input shaft. As the drive sprocket is driven by the turbine shaft, an AC signal is induced in the input speed sensor. Higher vehicle speeds induce a higher frequency and voltage at the sensor.
An air gap of 0.08-2.12 mm (0.0032-0.0834 in) must be maintained between the sensor and the drive sprocket to insure proper operation of the A/T ISS. The A/T ISS is used by the PCM in order to control line pressure, TCC apply and release and transmission shift patterns. This sensor is also used to calculate the appropriate gear ratios and TCC slippage.
This diagnostic indicates stuck, erratic, or intermittent values, indicating poor performance of the system.
If the PCM detects an unrealistically large change in data from the A/T ISS in a short period of time, then DTC P0716 sets. DTC P0716 is a Type B DTC.
Conditions for Setting the DTC
DTC P0716 sets during the second consecutive trip in which the following conditions occur:
| • | No TP sensor DTCs P0121, P0122 or P0123 are set. |
| • | No VSS DTCs P0502 or P0503 are set. |
| • | No A/T ISS sensor DTC P0717 is set and DTC P0717 has passed this ignition cycle. |
| • | No 1-2 shift solenoid valve DTCs P0751 or P0753 are set. |
| • | No 2-3 shift solenoid valve DTCs P0756 or P0758 are set. |
| • | The vehicle speed is greater than 8 km/h (5 mph). |
| • | The throttle position angle is greater than 14%. |
| • | The engine speed is greater than 500 RPM for 5 seconds and not in fuel shut off. |
| • | The input shaft speed changes by greater than 1300 RPM in 0.8 seconds. |
Action Taken When the DTC Sets
| • | The PCM illuminates the Malfunction Indicator Lamp (MIL). |
| • | The PCM freezes shift adapts. |
| • | The PCM inhibits TCC. |
| • | The PCM inhibits 4th gear if the transmission is in Hot Mode. |
| • | The PCM stores DTC P0716 in PCM history. |
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 clears the DTC from the PCM history. |
| • | The PCM clears the DTC from the PCM history if the vehicle completes 40 consecutive warm-up cycles without an 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. |
Diagnostic Aids
| • | Check for electromagnetic interference (EMI) in circuits 1230 (RED/BLK) and 1231 (DK BLU/WHT). EMI may be induced by a misrouted wiring harness along the spark plug wires. |
| • | Inspect the wiring at the PCM, the transmission 20-way connector, the A/T ISS 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 |
| - | Corrosion |
| • | 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.
-
This step verifies that the PCM receives a signal from the A/T ISS sensor.
-
This step verifies that there are no opens in the circuitry from the A/T ISS to the PCM.
-
This step verifies that there are no opens in the circuitry from the A/T ISS to the transmission 20-way connector.
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This step performs a resistance check on the A/T ISS and the automatic transmission wiring harness assembly.
-
Because of the harsh conditions inside the transmission, repairing the automatic transmission wiring harness assembly (A/T Wiring Harness Assembly) is not acceptable. It must be replaced if it is damaged in any way.
Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls | |||||||
Important: Before clearing the DTCs, 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 shaft 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 volts | |||||||||
Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found and corrected? | -- | |||||||||
5 |
Does the DMM display a resistance greater than the specified value? | 1127 ohms at 20°C (68°F) 1428 ohms at 88°C (190°F) | ||||||||
Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | |||||||||
7 | Is the resistance less than the specified value? | 893 ohms at 20°C (68°F) 1132 ohms at 88°C (190°F) | ||||||||
8 |
Refer to General Electrical Diagnosis in Wiring Systems. Was a condition found? | -- | ||||||||
Replace the Automatic Transmission Wiring Harness Assembly. Refer to Solenoids and Wiring Harness Replacement . Is the replacement complete? | -- | -- | ||||||||
10 | Replace the Automatic Transmission Input Shaft Speed Sensor. Refer to Input Speed Sensor Replacement . Is the replacement complete? | -- | -- | |||||||
11 | Inspect PCM connector C1 for bent, damaged or backed out connector pins. Was a condition found and corrected? | -- | ||||||||
12 | Replace the PCM. Refer to Powertrain Control Module Replacement/Programming in Engine Controls. Is the replacement complete? | -- | -- | |||||||
13 | Perform the following procedure in order to verify the repair:
Has the test run and passed? | -- | System OK |
