Diagnostic Instructions
DTC Descriptor
DTC P1811: Maximum Adapt and Long Shift
Circuit/System Description
The transmission pressure is modified by an adaptive modifier, which controls the shift execution time. The powertrain control module (PCM) monitors the time required to accomplish the shift. If the shift takes longer than 0.65 second and
the adaptive modifier cannot shorten this time, then a counter increases by 1.
Conditions for Running the DTC
The shift is adaptable.
Conditions for Setting the DTC
The 1-2, 2-3, or 3-4 shift is longer than 0.65 second, twice in 1 trip.
Action Taken When the DTC Sets
| • | DTC P1811 is a type C DTC. |
| • | The PCM commands maximum line pressure. |
| • | The PCM freezes transmission adaptive functions. |
Conditions for Clearing the DTC
DTC P1811 is a type C DTC.
Diagnostic Aids
DTC P1811 detects shift time that exceeds 0.65 second, indicating increased pressure is needed, but the transmission adaptive pressure (TAP) cell for the shift has already reached maximum value.
Reference Information
Schematic Reference
Automatic Transmission Controls Schematics
Connector End View Reference
Component Connector End Views
Description and Operation Reference
Electrical Information Reference
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference
Control Module References
for scan tool information
Special Tools
| • | J 44257
Main Wiring Harness Connector Remover |
Circuit/System Verification
| • | Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data. |
Circuit/System Testing
Important: You must perform the Circuit/System Verification before proceeding with Circuit/System Testing.
- Perform the
Line Pressure Check
. The pressures should be within specification.
| ⇒ | If the pressures are not within specifications, inspect and repair the following components: |
| • | PC solenoid valve damaged or contaminated |
| • | Pressure regulator valve line-up binding or damaged |
- Using the scan tool, observe the shift times for the 1-2 upshift. The 1-2 shift time should be less than 0.65 second.
| ⇒ | If the shift time is greater than 0.65 second, inspect and repair the following components: |
| • | 1-2 accumulator piston seals rolled or damaged |
| • | Second clutch piston and seal assembly binding or damaged |
| • | Second clutch fiber and steel plates not assembled correctly, burned, or damaged |
- Using the scan tool, observe the shift times for the 2-3 upshift. The 2-3 shift time should be less than 0.65 second.
| ⇒ | If the 2-3 shift time is greater than 0.65 second, inspect and repair the following components: |
| • | 2-3 accumulator piston seals rolled or damaged |
| • | Third clutch piston seal rolled or damaged |
| • | Third clutch piston damaged or not assembled correctly |
| • | Third clutch fiber and steel plates not assembled correctly, burned, or damaged |
- Using the scan tool, observe the shift times for the 3-4 upshift. The 3-4 shift time should be less than 0.65 second.
| ⇒ | If the 3-4 shift time is greater than 0.65 second, inspect and repair the following components: |
| • | 3-4 accumulator piston seals rolled or damaged |
| • | Fourth clutch piston seal rolled or damaged |
- Replace the automatic transmission fluid and filter. Add new automatic transmission fluid. Refer to
Transmission Fluid Check
.
| ⇒ | If the fluid is not at the proper level, add fluid as necessary. |
Important: The Reset Transmission Adapts function will clear all adapt cells. This may affect transmission performance. The PCM will update the transmission adapt cell values as the vehicle is driven
- Perform the Transmission Adapts function.
Repair Instructions
Perform the
Diagnostic Repair Verification
after completing the diagnostic procedure.
