5L40-E/5L50-E - Automatic Transmission
DTC P1876
TAP Shift Circuit Performance:
Circuit Description
The TAP Shift system allows the driver to manually shift gears by using the Upshift and Downshift positions located on the automatic transmission shift Lever. Pushing the lever to the Upshift position will command an upshift and pushing the lever to the Downshift position 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 transmission control module (TCM) detects TAP enable switch Active and the IMS does not indicate D5, DTC P1876 sets. DTC P1876 is a type C DTC.
DTC Descriptor
This diagnostic procedure supports the following DTC:
DTC P1876 Up and Down Shift Switch Performance - Range Switch Not in D3
Conditions for Running the DTC
* No TAP system DTCs P0815, P0816 or P0826.
* No IMS range DTCs P1815, P1820, P1822, P1823, P1825 or P1826.
* The engine run time is greater than 5 seconds.
* No CAN errors present.
Conditions for Setting the DTC
The TCM detects the TAP enable switch is Active and the IMS range is not D5 for 5 seconds.
Action Taken When the DTC Sets
* The TCM does not request the ECM to illuminate the malfunction indicator lamp (MIL).
* The TCM disables TAP Shift operation.
* The TCM records the operating conditions when the Conditions for Setting the DTC are met. The TCM stores this information a Failure Record.
* The TCM stores DTC P1876 in TCM 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 ignition is OFF long enough in order to power down the TCM.
Step 1 - Step 7:
Step 8 - Step 18:
