P1811

DIAGNOSTIC TROUBLE CODE (DTC) P1811 MAXIMUM ADAPT AND LONG SHIFT





Circuit Description
The transmission line pressure is modified by the PCM through the Pressure Control Solenoid Valve (PC Sol. Valve) to control the gear shift execution time and shift consistency. The PCM monitors various inputs and modifies the shift execution and timing by applying a calculated duty cycle to the PC Sol. Valve, the PCM alters the shifting based on driving habits, transmission load and internal transmission condition.
When the PCM detects long shifts that can not be shortened by shift adapts during the same ignition cycle, then DTC P1811 sets.


Conditions For Setting The DTC
- Shift time is greater than 1 second at maximum adapt for a total four times per ignition cycle.


Action Taken When The DTC Sets
- PCM will not illuminate the Malfunction Indicator Lamp.
- PCM will command maximum line pressure.
- PCM will freeze shift adapts from being updated.
- DTC P1811 will be stored in PCM memory.


Conditions For Clearing The DTC
- After each ignition cycle without the fault condition present.
- To cancel DTC fail actions, the fault must no longer exist and the ignition must be cycled off for five seconds.
- History DTC(s) can be cleared by using a Scan Tool.


Diagnostic Aids
- Question the owner for the possibility of vehicle overloading, exceeding trailer towing limit. or towing in overdrive.
- If after several attempts to gain accurate shift times and an adapt can be made, reset adapts and operate vehicle to assure proper shifting.


Test Description
The numbers below refer to the step numbers on the diagnostic chart.
2. This step checks for possible low fluid level causing delayed shift(s).
5. This step checks for possible low line pressure causing delayed shift(s).












DIAGNOSTIC TROUBLE CODE (DTC) P1811 MAXIMUM ADAPT AND LONG SHIFT