4T80-E - Automatic Transaxle
DTC P1811
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* ReviewStrategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) 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 second and the adaptive modifier cannot shorten this time, then an internal transmission control module (TCM) counter increases by 1.
Conditions for Running the DTC
* The shift is adaptable.
* The 1-2, 2-3, or 3-4 shift adapt has reached the maximum limit.
Conditions for Setting the DTC
The 1-2, 2-3, or 3-4 shift is longer than 0.65 second more than once per trip.
Action Taken When the DTC Sets
DTC P1811 is a Type C DTC.
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 (Connector Views)
Electrical Information Reference
* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)
DTC Type Reference
Powertrain Diagnostic Trouble Code (DTC) Type Definitions (Diagnostic Trouble Code Descriptions)
Scan Tool Reference
Control Module References (Programming and Relearning)
Circuit/System Verification
* Ensure the transmission fluid level is at the proper level by performing theTransmission Fluid Check (4T80-E Automatic Transaxle).
* Ensure the line pressure is within specification by performing theLine Pressure Check (Line Pressure Check Procedure).
Circuit/System Testing
1. Perform theTransmission Fluid Check (4T80-E Automatic Transaxle).
• If the level is not within specifications, repair as necessary.
2. Perform theLine 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
* Spacer plate and gasket damaged or not assembled correctly
* PC solenoid valve damaged or contaminated
* Pressure regulator valve line-up binding or damaged
* Torque signal valve line-up binding or damaged
* Oil pump assembly damaged or missing components
3. Verify the scan tool 1-2 Shift Time parameter is less than 0.65 seconds.
• If the shift time is greater than 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
* Forward servo assembly damaged or not assembled correctly
* Oil pump assembly damaged or missing components
* Spacer plate and gaskets damaged or not assembled correctly
* Driven sprocket support seals damaged or missing
* Second clutch piston and seal assembly binding or damaged
* Second clutch fiber and steel plates not assembled correctly, burned, or damaged
* Second clutch spring assembly damaged or not assembled correctly
* Forward band burned, damaged, or not assembled correctly
* 1-2 support roller clutch assembly damaged or not assembled correctly
4. Verify the scan tool 2-3 Shift Time parameter is less than 0.65 seconds.
• If the 2-3 shift time is greater than 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
* Oil pump assembly damaged or missing components
* Spacer plate and gaskets damaged or not assembled correctly
* Driven sprocket support seals damaged or missing
* 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
* Third clutch spring assembly damaged or not assembled correctly
* Third sprag clutch assembly damaged or not assembled correctly
5. Verify the scan tool 3-4 Shift Time parameter is less than 0.65 seconds.
• If the 3-4 shift time is greater than 0.65 seconds, inspect and repair the following components:
* Oil pump assembly damaged or missing components
* Spacer plate and gaskets damaged or not assembled correctly
* 3-4 accumulator piston seals rolled or damaged
* 3-4 accumulator piston and pin missing, binding, or damaged
* Fourth clutch piston seal rolled or damaged
* Fourth clutch piston damaged, not assembled correctly, or seized
* Fourth clutch fiber and steel plates not assembled correctly, burned, or damaged
* Fourth clutch spring assembly damaged or not assembled correctly
6. Replace the automatic transmission fluid and filter. Refer to Transmission Fluid Check (4T80-E Automatic Transaxle).
• 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 TCM will update the transmission adapt cell values as the vehicle is driven.
7. Perform the Reset Transmission Adapts function.
Repair Instructions
Perform the Diagnostic Repair Verification (Verification Tests) after completing the repair.