Circuit/System Testing

WARNING: This page is about a different car, the 2008 Buick LaCrosse and 2008 Buick Allure. However, it is still accessible from the selected car via links, so may be relevant.

Perform the Transmission Fluid Check .
- If the level is not within specifications, repair as necessary.
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 damaged or not assembled correctly
    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) or Control Valve Body Disassemble (With Touch Activated Power) .
  - Oil pump assembly damaged or missing components
    Refer to Transmission Fluid Pump Disassemble .
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
  - 1-2 accumulator piston and pin missing, binding, or damaged
    Refer to Accumulator Components Disassemble .
  - Forward servo assembly damaged or not assembled correctly
    Refer to Forward Servo Removal .
  - Oil pump assembly damaged or missing components
    Refer to Transmission Fluid Pump Disassemble .
  - Spacer plate and gaskets damaged or not assembled correctly
    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 not assembled correctly, burned, or damaged
  - Second clutch spring assembly damaged or not assembled correctly
    Refer to 2nd Clutch Disassemble .
  - Forward band burned, damaged, or not assembled correctly
    Refer to 1-2 Support Drum and Forward Band Removal .
  - 1-2 support roller clutch assembly damaged or not assembled correctly
    Refer to 1-2 Support Roller Clutch Disassemble .
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
  - 2-3 accumulator piston and pin missing, binding, or damaged
    Refer to Accumulator Components Disassemble .
  - Oil pump assembly damaged or missing components
    Refer to Transmission Fluid Pump Disassemble .
  - Spacer plate and gaskets damaged or not assembled correctly
    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 not assembled correctly
  - Third clutch fiber and steel plates not assembled correctly, burned, or damaged
  - Third clutch spring assembly damaged or not assembled correctly
    Refer to Input and 3rd Clutch Disassemble .
  - Third sprag clutch assembly damaged or not assembled correctly
    Refer to Input and 3rd Clutch Pawl Disassemble .
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:
  - Oil pump assembly damaged or missing components
    Refer to Transmission Fluid Pump Disassemble .
  - Spacer plate and gaskets damaged or not assembled correctly
    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, not assembled correctly, or seized
    Refer to Driven Sprocket Support Assembly Removal .
  - Fourth clutch fiber and steel plates not assembled correctly, burned, or damaged
    Refer to 4th Clutch Components Removal .
  - Fourth clutch spring assembly damaged or not assembled correctly
    Refer to Driven Sprocket Support Assembly Removal .
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 TCM will update the transmission adapt cell values as the vehicle is driven

Perform the Transmission Adapts function.