P0816
DTC P0816 (5.3L)
Circuit Description
The TAP shift system allows the driver to manually shift gears by using the TAP shift switches located on the steering wheel. Pushing either TAP shift switch will command an upshift and pulling the switch will command a downshift. The TAP shift system is activated when the gear selector is in the manual, M, position and is deactivated in all other positions.
If the TCM detects a downshift or an up and downshift request for an extended period of time, then DTC P0816 sets. DTC P0816 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P0816 Downshift Switch Circuit
Conditions for Running the DTC
^ No TAP shift DTC P0826.
^ The engine speed is greater than 500 RPM for 5 seconds.
^ The time since last gear selector range change is 6 seconds or more.
Conditions for Setting the DTC
The TCM detects a downshift or an up and downshift request for 1 second in PARK and for 10 minutes in D4.
Action Taken When the DTC Sets
^ The TCM does not illuminate the malfunction indicator lamp (MIL).
^ The TCM disables TAP shift operation.
^ The TCM commands an alternate coast shift pattern where downshifts occur at higher vehicle speeds while coasting.
^ The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information as Failure Records.
^ The TCM stores DTC P0816 in PCM history.
Conditions for Clearing the DTC
^ A scan tool can clear the DTC.
^ 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 DTC passes.
