P1811 BUICK, CADILLAC, CHEVROLET, GMC: MAXIMUM ADAPTIVE & LONG TERM SHIFT
POST UPDATED IN February, 2023
P1811 BUICK, CADILLAC, CHEVROLET, GMC: MAXIMUM ADAPTIVE & LONG TERM SHIFT
The adaptive modifier changes the transmission line pressure. Besides, It controls the shift run time, and the shift time is monitored before shifting.
The OBDII fault code P1811 occurs once the Powertrain Control Module (PCM) detects that the shift took longer than 0.65 seconds, preventing the adaptive modifier from not reducing the shift time. This situation occurs while the engine is running and when the adaptive shifting has reached its limit.
Reasons for setting the P1811 OBD2 diagnostic code:
To troubleshoot the P1811 OBDII DTC: