P1811

DTC P1811

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions provides an overview of each diagnostic category.



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. 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 (Electrical Diagrams)
Connector End View Reference

Component Connector End Views
Description and Operation

Transmission Adaptive Functions (Transmission Adaptive Functions)
Electrical Information Reference

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

DTC Type Reference

Powertrain Diagnostic Trouble Code (DTC) Type Definitions
Scan Tool Reference

Control Module References for scan tool information


Circuit/System Verification

Ensure that the transmission fluid level is at the proper level by performing the Transmission Fluid Check (Transmission Fluid Checking Procedure) . 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 (Transmission Fluid Checking Procedure) .

• 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 (Service and Repair) .
* Spacer plate and gasket damage or misassembled-refer to Control Valve Body Assemble (Overhaul) .
* 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 (Overhaul) .
* Oil pump assembly damaged or missing components-refer to Oil Pump Cleaning and Inspection (Overhaul) .

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 (Overhaul) .
* 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 (Overhaul) .
* Internal fluid passage leaks
* Casting porosity or damage
Refer to Case Inspection (Overhaul) .
* Damaged gasket or spacer plate
* Out-of-position gasket or spacer plate
Refer to Control Valve Body Disassemble (Overhaul) .
* Slipping forward clutch
* Damaged sprag clutch, not holding
Refer to Direct/Coast Clutch, Reaction Carrier Disassemble (Overhaul) .
* 2nd roller clutch damaged, not holding
Refer to Reverse Input and Second Roller Clutch Disassemble (Overhaul) .

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 (Overhaul) .
* 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 (Overhaul) .
* Leaking driven sprocket support seals
* Damaged driven sprocket support seals
* Damaged driven sprocket support
Refer to Driven Sprocket Support Assembly Disassemble (Overhaul) .
* Internal fluid passage leaks
* Casting porosity or damage
Refer to Case Inspection (Overhaul) .
* Damaged gasket or spacer plate
* Out-of-position gasket or spacer plate
Refer to Control Valve Body Disassemble (Overhaul) .

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 (Overhaul) .
* 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 (Overhaul) .
* Burned intermediate/4th band
* Out-of-position intermediate/4th band
* Damaged intermediate/4th band
* Slipping intermediate/4th band
Refer to Intermediate Fourth Band Removal (Overhaul) .
* Internal fluid passage leaks
* Casting porosity or damage
Refer to Case Inspection (Overhaul) .
* Damaged gasket or spacer plate
* Out-of-position gasket or spacer plate
Refer to Control Valve Body Disassemble (Overhaul) .
* Slipping direct clutch
Refer to Direct/Coast Clutch, Reaction Carrier Disassemble (Overhaul) .

6. Change the AT fluid and filter. Add new AT fluid, refer to Transmission Fluid Check (Transmission Fluid Checking Procedure) .

• 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.



Repair Instructions

Perform the Diagnostic Repair Verification after completing the repair.