P1811 BUICK, CADILLAC, CHEVROLET, GMC: MAXIMUM ADAPTIVE & LONG TERM SHIFT
Description of DTC code P1811
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.
The transmission adaptation functions are disabled.
Causes of OBD2 P1811
Reasons for setting the P1811 OBD2 diagnostic code:
The line pressure may not be enough.
The pressure control solenoid wires or connectors may be damaged.
The pressure control solenoid may be faulty.
Possible solutions of the DTC code P1811
To troubleshoot the P1811 OBDII DTC:
First, consult the Service Bulletins.
Check that the transmission fluid available is enough. Also, check that the line pressure matches the value specified by the manufacturer. If any of these factors are inconsistent, make the necessary repairs.
Check the condition of the pressure control solenoid wires and connectors. If damage due to corrosion, burns, or wear is discovered, make repairs.
Check the pressure control solenoid for damage to the clamps, which may cause leakage. If you detect some of these conditions, make corrections.