P1811

DTC P1811

DTC Descriptor

DTC P1811 Maximum Adapt and Long Shift

Diagnostic Fault Information

Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Initial Inspection and Diagnostic Overview

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 Check. Testing and Inspection Ensure that the line pressure is within specification by performing the Line Pressure Check. Line Pressure Check Procedure

Circuit/System Testing

1. Perform the Transmission Fluid Check. Testing and Inspection
- If the level is not within specifications, repair as necessary.

2. Perform the Line Pressure Check. Line Pressure Check Procedure
- 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 Assemble in Transmission Unit Repair.
- 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 in Transmission Unit Repair.
- Oil pump assembly damaged or missing components-refer to Oil Pump Cleaning and Inspection in Transmission Unit Repair.

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:

- Leaking 1-2 accumulator piston seals
- Rolled 1-2 accumulator piston seals
- Cut 1-2 accumulator piston seals
Refer to Channel Plate Assembly Disassemble in Unit Repair.
- Leaking 2nd clutch piston seals
- Rolled 2nd clutch piston seals
- Cut 2nd clutch piston seals
- Burned 2nd clutch plates
- Damaged 2nd clutch plates
- Broken 2nd clutch springs
- Out-of-position 2nd clutch springs
- Damaged 2nd clutch piston
- Cracked or damaged driven sprocket support
- Leaking driven sprocket support seals
- Damaged driven sprocket support seals
Refer to Driven Sprocket Support Assembly Disassemble in Unit Repair.
- Internal fluid passage leaks
- Casting porosity or damage
Refer to Case Inspection in Unit Repair.
- Damaged gasket or spacer plate
- Out-of-position gasket or spacer plate
Refer to Control Valve Body Disassemble in Unit Repair.
- Slipping forward clutch
- Damaged sprag clutch, not holding
Refer to Direct/Coast Clutch, Reaction Carrier Disassemble in Unit Repair.
- 2nd roller clutch damaged, not holding
Refer to Reverse Input and Second Roller Clutch Disassemble in Unit Repair.

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:

- Leaking 2-3 accumulator piston seals
- Rolled 2-3 accumulator piston seals
- Cut 2-3 accumulator piston seals
Refer to Channel Plate Assembly Disassemble in Unit Repair.
- Leaking direct clutch piston seals
- Rolled direct clutch piston seals
- Cut direct clutch piston seals
- Burned direct clutch plates
- Damaged direct clutch plates
- Broken direct clutch springs
- Out-of-position direct clutch springs
- Damaged direct clutch pistons
- Damaged, or not holding, sprag clutch
Refer to Direct/Coast Clutch, Reaction Carrier Disassemble in Unit Repair.
- Leaking driven sprocket support seals
- Damaged driven sprocket support seals
- Damaged driven sprocket support
Refer to Driven Sprocket Support Assembly Disassemble in Unit Repair.
- Internal fluid passage leaks
- Casting porosity or damage
Refer to Case Inspection in Unit Repair.
- Damaged gasket or spacer plate
- Out-of-position gasket or spacer plate
Refer to Control Valve Body Disassemble in Unit Repair.

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:

- Leaking 3-4 accumulator piston seals
- Rolled 3-4 accumulator piston seals
- Cut 3-4 accumulator piston seals
Refer to Channel Plate Assembly Disassemble in Unit Repair.
- Leaking intermediate/4th servo piston seals
- Rolled intermediate/4th servo piston seals
- Cut intermediate/4th servo piston seals
- Damaged intermediate/4th servo pin
- Seized intermediate/4th servo pin
- Damaged intermediate/4th servo piston
- Cracked intermediate/4th servo cover
- Leaking intermediate/4th servo cover
Refer to Intermediate/Fourth Servo Disassemble in Unit Repair.
- Burned intermediate/4th band
- Out-of-position intermediate/4th band
- Damaged intermediate/4th band
- Slipping intermediate/4th band
Refer to Intermediate Fourth Band Removal in Unit Repair.
- Internal fluid passage leaks
- Casting porosity or damage
Refer to Case Inspection in Unit Repair.
- Damaged gasket or spacer plate
- Out-of-position gasket or spacer plate
Refer to Control Valve Body Disassemble in Unit Repair.
- Slipping direct clutch
Refer to Direct/Coast Clutch, Reaction Carrier Disassemble in Unit Repair.

6. Change the AT fluid and filter. Add new AT fluid, refer to Transmission Fluid Check. 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 Check
* Line Pressure Check
* High or Low Line Pressure

Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair. Verification Tests