P0716
DTC P0716 (6.6L)
Circuit Description
The automatic transmission input shaft speed (AT ISS) sensor provides transmission input speed to the transmission control module (TCM). 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 magnetic field of the sensor. The AC voltage level increases as the turbine shaft speed increases. The TCM converts the AC voltage into a digital signal. The TCM determines actual turbine speed using the digital signal. The TCM uses the input speed to calculate torque converter slip speed, and gear ratios.
When the TCM 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, 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 sensor DTCs P0121, P0122 or P0123.
^ No VSS DTCs P0502 or P0503.
^ No ISS DTC P0717.
^ No 1-2 shift solenoid DTCs P0751, P0752 or P0753.
^ AT ISS DTC P0717 has run and passed.
^ The system voltage is 8 - 18 volts.
^ The TP angle is greater than 10 percent.
^ The vehicle speed is greater than 12 km/h (7 mph).
Conditions for Setting the DTC
The input speed varies by 1,300 RPM for greater than 5 seconds.
Action Taken When the DTC Sets
^ The TCM illuminates the malfunction indicator lamp (MIL) during the second consecutive trip for all California emission equipped vehicles in which the Conditions for Setting the DTC are met.
^ The TCM commands maximum line pressure.
^ The TCM freezes transmission adaptive functions.
^ The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Freeze Frame, California only, and Failure Records, California and Federal.
^ The TCM stores the DTC P0716 in TCM history during the second consecutive trip, California, or the first trip, Federal, in which the Conditions for Setting the DTC are met.
Conditions for Clearing the MIL/DTC
^ For California emissions, the TCM 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.
^ For California emissions, the TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without an emission related diagnostic fault occurring.
^ For Federal emissions, the TCM clears the DTC from TCM history if the vehicle completes 40 warm-up cycles without a non-emission related diagnostic fault occurring.
^ The TCM 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 TCM.
Diagnostic Aids
DTC P0716 defaults to an elevated line pressure condition which may result in partial torque converter clutch (TCC) apply. This may produce an idle surge that could stall the engine.
Test Description
The number below refers to the step number on the diagnostic table.
2. This step tests for proper operation of the AT ISS sensor.
