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P1811



DTC P1811

DTC Descriptor

DTC P1811 Maximum Adapt and Long Shift

Diagnostic Fault Information

Important: Always perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.

Circuit/System Description

The transmission pressure is modified by an adaptive modifier which controls the shift execution time. This diagnostic tests the time required to accomplish the shift. If the shift takes longer than 0.65 seconds and the adaptive modifier cannot shorten this time, then a counter increases by one.

Conditions for Running the DTC

* The shift is adaptable.
* The 1-2, 2-3, or 3-4 shift adapt cell has reached the limit.

Conditions for Setting the DTC

The 1-2, 2-3, or 3-4 shift is longer than 0.65 seconds, twice in one trip.

Action Taken When the DTC Sets

* DTC P1811 is a Type C DTC.
* The TCM commands maximum line pressure.
* The TCM freezes transmission adaptive functions.

Conditions for Clearing the DTC

DTC P1811 is a Type C DTC.

Reference Information

Schematic Reference

Automatic Transmission Controls Schematics

Connector End View Reference
* Automatic Transmission Inline 20-Way Connector End View
* Automatic Transmission Internal Connector End Views
* Automatic Transmission Related Connector End Views

Electrical Information Reference
* Circuit Testing
* Connector Repairs
* Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs

Scan Tool Reference
* Scan Tool Data List
* Scan Tool Data Definitions
* Scan Tool Output Controls

DTC Type Reference
* Diagnostic Trouble Code (DTC) Type Definitions
* Diagnostic Trouble Code (DTC) List/Type

Circuit/System Verification

Ensure that the transmission fluid level is at the proper level by performing the Transmission Fluid Checking. Ensure that the line pressure is within specification by performing the Line Pressure Check.

Circuit/System Testing

1. Perform the Transmission Fluid Checking.

^ If the level is not within specifications, repair as necessary.

2. Perform the Line Pressure Check.

^ If the pressures are not within specifications, inspect and repair the following components:

* Oil filter and seal missing, plugged, or damaged. Refer to Automatic Transmission Fluid Filter and Seal Replacement.
* Spacer plate and gasket damage or misassembled. Refer to Control Valve Body and Spacer Plate Assemble.
* PC solenoid valve damaged or contaminated
* Pressure regulator valve line-up binding or damaged
* Torque signal valve line-up binding or damaged. Refer to Control Valve Body Disassemble (Without Touch Activated Power) Control Valve Body Disassemble (With Touch Activated Power).
* Oil pump assembly damaged or missing components. Refer to Oil Pump Components Disassemble.

3. Using the scan tool observe the shift times for the 1-2 upshift. The 1-2 shift time should be less than 0.65 seconds.

^ If the shift time is above 0.65 seconds, inspect and repair the following components:

* 1-2 accumulator piston seals rolled or damaged
* 1-2 accumulator piston and pin missing, binding, or damaged. Refer to Accumulator Components Disassemble.
* Forward servo assembly damaged or misassembled. Refer to Forward Servo Removal.
* Oil pump assembly damaged or missing components. Refer to Oil Pump Components Disassemble.
* Spacer plate and gaskets damaged or misassembled. Refer to Control Valve Body and Spacer Plate Assemble.
* Driven sprocket support seals damaged or missing. Refer to Driven Sprocket Support Assembly Removal.
* Second clutch piston and seal assembly binding or damaged
* Second clutch fiber and steel plates misassembled, burned, or damaged
* Second clutch spring assembly damaged or misassembled. Refer to Second Clutch Disassemble.
* Forward band burned, damaged, or misassembled. Refer to 1-2 Support Drum and Forward Band Removal.
* 1-2 support roller clutch assembly damaged or misassembled. Refer to 1-2 Support Roller Clutch Disassemble.

4. Using the scan tool observe the shift times for the 2-3 upshift. The 2-3 shift time should be less than 0.65 seconds.

^ If the 2-3 shift time is above 0.65 seconds, inspect and repair the following components:

* 2-3 accumulator piston seals rolled or damaged
* 2-3 accumulator piston and pin missing, binding, or damaged. Refer to Accumulator Components Disassemble.
* Oil pump assembly damaged or missing components. Refer to Oil Pump Components Disassemble.
* Spacer plate and gaskets damaged or misassembled. Refer to Control Valve Body and Spacer Plate Assemble.
* Driven sprocket support seals damaged or missing. Refer to Driven Sprocket Support Assembly Removal.
* Third clutch piston seal rolled or damaged
* Third clutch piston damaged or misassembled
* Third clutch fiber and steel plates misassembled, burned, or damaged
* Third clutch spring assembly damaged or misassembled. Refer to Input Clutch and Third Clutch Disassemble.
* Third sprag clutch assembly damaged or misassembled. Refer to Input and 3rd Clutch Pawl Disassemble.

5. Using the scan tool observe the shift times for the 3-4 upshift. The 3-4 shift time should be less than 0.65 seconds.

^ If the 3-4 shift time is above 0.65 seconds, inspect and repair the following components:

* Oil pump assembly damaged or missing components. Refer to Oil Pump Components Disassemble.
* Spacer plate and gaskets damaged or misassembled. Refer to Control Valve Body and Spacer Plate Assemble.
* 3-4 accumulator piston seals rolled or damaged
* 3-4 accumulator piston and pin missing, binding, or damaged. Refer to Case Assembly Inspection.
* Fourth clutch piston seal rolled or damaged
* Fourth clutch piston damaged, misassembled, or seized. Refer to Driven Sprocket Support Assembly Removal.
* Fourth clutch fiber and steel plates misassembled, burned, or damaged. Refer to Fourth Clutch Components Removal.
* Fourth clutch spring assembly damaged or misassembled. Refer to Driven Sprocket Support Assembly Removal.

6. Change the AT fluid and filter. Add new AT fluid, refer to Transmission Fluid Checking. Testing and Inspection

^ If the fluid is not at the proper level, add as necessary.

Important: The Reset Transmission Adapts function will clear all adapt cells. This may affect transmission performance. The TCM will update the transmission adapt cell values as the vehicle is driven

7. Perform the Transmission Adapts function.

Component Testing

Transmission Fluid Checking

Line Pressure Check

Incorrect Line Pressure

Repair Instructions

Important: Always perform the Diagnostic Repair Verification after completing the repair. Verification Tests