LEMON Manuals: Even more car manuals for everyone
Home >> GMC >> 2003 >> Safari Van Cargo, AWD >> Repair and Diagnosis >> External Pages >> Different car >> Section 220 (Automatic Transaxle Diagnosis - 4T65-E) >> Diagnostic Tests >> DTC P1811: Maximum Adapt & Long Shift >> Diagnostic Procedure

Diagnostic Procedure

WARNING: This page is about a different car, the 2003 Buick Regal and 2003 Buick Century. However, it is still accessible from the selected car via links, so may be relevant.
  1. Did you perform the diagnostic system check? If so, go to next step. If not, see DIAGNOSTIC SYSTEM CHECK  under SELF-DIAGNOSTIC SYSTEM.
  2. Did you perform the transmission fluid checking procedure? If so, go to next step. If not, perform the transmission fluid checking procedure. See CHECKING FLUID LEVEL & CONDITION under LUBRICATION in SERVICING - CENTURY & REGAL article.
  3. Install a scan tool. Turn ignition ON, engine OFF. Before clearing the DTCs, use the scan tool to record the failure records for reference. Using the Clear Info function will erase the stored failure records from the PCM. Record the failure records. Clear the DTCs. Are any of DTCs P0121, P0122, P0123, P0218, P0502, P0503, P0711, P0712, P1121 or P1122 also set? If so, go to next step. If not, go to step  5 .
  4. Diagnose the above DTCs first. Is the diagnosis and repair complete? If so, go to step  14 .
  5. Use the scan tool snapshot mode to record the shift times. Drive the vehicle in D4 to obtain a 1-2, 2-3 and 3-4 upshift. Record the shift times. Did all the shift times exceed .65 seconds? If so, go to next step. If not, go to step  8 .
  6. Perform the line pressure check. See HYDRAULIC PRESSURE TESTS  under PERFORMANCE TESTS. Is the line pressure within specifications? If so, see DIAGNOSTIC AIDS  . If not, go to next step.
  7. Inspect the transaxle for the following conditions:
    • Fluid level low.
    • Oil filter and seal missing, plugged or damaged.
    • Spacer plate and gasket damaged or misassembled.
    • Pressure Control (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.

    Repair as necessary. Did you complete the repair? If so, go to step  14 .

  8. Did the 1-2 shift time exceed .65 seconds? If so, go to next step. If not, go to step  10 .
  9. Inspect the transaxle for the following conditions:
    • 1-2 accumulator piston seals rolled or damaged.
    • 1-2 accumulator piston and pin missing, binding or damaged.
    • Forward servo assembly damaged or misassembled.
    • Oil pump assembly damaged or missing components.
    • Spacer plate and gaskets damaged or misassembled.
    • Driven sprocket support seals damaged or missing.
    • 2nd clutch piston and seal assembly binding or damaged.
    • 2nd clutch fiber and steel plates misassembled, burned or damaged.
    • 2nd clutch spring assembly damaged or misassembled.
    • Forward band burned, damaged or misassembled.
    • 1-2 support roller clutch assembly damaged or misassembled.

    Repair as necessary. Did you complete the repair? If so, go to step  14 .

  10. Did the 2-3 shift time exceed .65 seconds. If so, go to next step. If not, go to step  12 .
  11. Inspect the transaxle for the following conditions:
    • 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 misassembled.
    • Driven sprocket support seals damaged or missing.
    • 3rd clutch piston seal rolled or damaged.
    • 3rd clutch piston damaged or misassembled.
    • 3rd clutch fiber and steel plates misassembled, burned or damaged.
    • 3rd clutch spring assembly damaged or misassembled.
    • 3rd sprag clutch assembly damaged or misassembled.

    Repair as necessary. Did you complete the repair? If so, go to step  14 .

  12. Did the 3-4 shift time exceed .65 seconds? If so, go to next step. If not, see DIAGNOSTIC AIDS  .
  13. Inspect the transaxle for the following conditions:
    • Oil pump assembly damaged or missing components.
    • Spacer plate and gaskets damaged or misassembled.
    • 3-4 accumulator piston seals rolled or damaged.
    • 3-4 accumulator piston and pin missing, binding or damaged.
    • 4th clutch piston seal rolled or damaged.
    • 4th clutch piston damaged, misassembled or seized.
    • 4th clutch fiber and steel plates misassembled, burned or damaged.
    • 4th clutch spring assembly damaged or misassembled.

    Repair as necessary. Did you complete the repair? If so, go to next step.

  14. Change the transmission fluid and filter. See DRAINING & REFILLING under LUBRICATION in SERVICING - CENTURY & REGAL article. Using the scan tool, perform the CLEAR TAPS function. Did you complete the above procedure? If so, go to next step.
    NOTE: The CLEAR TAPS function will clear all adapt cells. This may affect transaxle performance. The PCM will update the transaxle adapt cell values as the vehicle is driven.
  15. Perform the following procedure to verify the repair:
    • Select DTC.
    • Select Clear Info.
    • Drive the vehicle in D4.
    • Observe "Last Shift Time" on the scan tool.
    • Ensure that the 1-2, 2-3 and 3-4 shift times are each less than .65 second.

    Was each shift time less than .65 second? If so, go to next step. If not, go to step  2 .

  16. With a scan tool, observe the stored information, capture info and DTC info. Does the scan tool display any DTCs that you have not diagnosed? If so, go to appropriate ENGINE PERFORMANCE article. If not, the system is OK.
scientia non olet · About LEMON Manuals