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Home >> Isuzu >> 2007 >> i-290 LS, Standard >> Repair and Diagnosis >> External Pages >> Different car >> Section 67 (Automatic Transaxle - 4T80-E - DTC P01811 To DTC P2764) >> DTC P1811 >> Test Description

Test Description

WARNING: This page is about a different car, the 2007 Cadillac DTS. However, it is still accessible from the selected car via links, so may be relevant.

The numbers below refer to the step numbers on the diagnostic table.

  1. 3:  This step reviews the 1-2 adapt cells. If the pressure readings match or exceed the value listed in the value column, then the TCM modifies the base line pressure on a 1-2 shift. This modification adjusts the holding effort of a clutch or band.
  2. 4:  This step reviews the 2-3 adapt cells. If pressure readings match or exceed the value listed in the value column, then the TCM modifies the base line pressure on a 2-3 shift. This modification adjusts the holding effort of a clutch or band.
  3. 5:  This step reviews the 3-4 adapt cells. If pressure readings match or exceed the values listed in the value column, then the TCM modifies the base line pressure on a 3-4 shift. This modification adjusts the holding effort of a clutch or band.
  4. 6:  This step inspects or repairs any of the components listed. A faulty component may lead to a maximum adapt and long shift during a 1-2 upshift.
  5. 7:  This step inspects or repairs any of the components listed. A faulty component may lead to a maximum adapt and long shift during a 2-3 upshift.
  6. 8:  This step inspects or repairs any of the components listed. A faulty component may lead to a maximum adapt and long shift during a 3-4 upshift.
  7. 9:  This step inspects components located within the valve body, if the fluid pressure gage readings do not match the commanded PC solenoid valve current to line pressure located in the value column.
DTC P1811

Step Action Values Yes No
1 Did you perform the Diagnostic System Check - Vehicle? - Go to Step 2  Go to Diagnostic System Check - Vehicle
2 Did you perform the Transmission Fluid Checking Procedure? - Go to Step 3  Go to Transmission Fluid Checking
3 
  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
    3. IMPORTANT: Before clearing the DTC, use the scan tool in order to record the Failure Records. Using the Clear Info function erases the Failure Records from the TCM.
  3. Record the DTC Failure Records.
  4. Clear the DTC.
  5. Select Transmission Adapts/1-2 Adapt. Data on the scan tool.
  6. Review the 1-2 TAP cells 4-16.
Do any cells display a value equal to or greater than the specified value?		 184.48 kPa
(26.75 psi)		 Go to Step 6  Go to Step 4 
4 
  1. Select Transmission Adapts/2-3 Adapt. Data on the scan tool.
  2. Review the 2-3 TAP cells 4-16.
Do any cells display a value equal to or greater than the specified value?		 184.48 kPa
(26.75 psi)		 Go to Step 7  Go to Step 5 
5 
  1. Select Transmission Adapts/3-4 Adapt. Data on the scan tool.
  2. Review the 3-4 TAP cells 4-16.
Do any cells display a value equal to or greater than the specified value?		 184.48 kPa
(26.75 psi)		 Go to Step 8  Go to Step 9 
6 
  1. Inspect the following items:
    • The line pressure is too low.

      Refer to Line Pressure .

    • The pressure control solenoid valve is stuck ON.
    • The pressure control solenoid valve has a broken clamp causing leakage.
    • The 1-2 shift solenoid valve is stuck ON.
    • The 1-2 shift valves (A & B) are stuck in 1st gear.

      Refer to Upper Control Valve Body Disassemble .

    • The clutch plates (431 through 435) are burned or damaged.
    • The 2nd clutch piston assembly is cracked or damaged.
    • The 2nd clutch return spring and retainer assembly is damaged or out of position.
    • The 2nd clutch piston assembly seals are rolled, damaged or leaking.

      Refer to Second Clutch Plates and Reverse Clutch Removal .

    • The 2nd sprag clutch assembly is damaged or not holding.

      Refer to Reverse Clutch Housing and Second Sprag Disassemble .

  2. Repair any of the above items as necessary.
Is the repair complete?		 - Go to Step 14  -
7 
  1. Inspect the following items:
  2. Repair any of the above items as necessary.
Is the repair complete?		 - Go to Step 14  -
8 
  1. Inspect the following items:
  2. Repair any of the above items as necessary.
Is the repair complete?		 - Go to Step 14  -
9 
  1. Install the J 21867  Pressure Gage and J 21867-94  Line Pressure Fitting. See Special Tools .
  2. Start the engine.
  3. Using the scan tool command the PC solenoid valve current high, then command the PC solenoid valve current low and observe the pressure gage.
Does the scan tool display match the specified pressure gage parameters?		 0.10 A = 240-260 psi
0.20 A = 210-250 psi
0.30 A = 190-240 psi
0.40 A = 175-210 psi
0.50 A = 150-200 psi
0.60 A = 125-175 psi
0.70 A = 110-160 psi
0.80 A = 80-130 psi
0.90 A = 75-125 psi		 Go to Diagnostic Aids Go to Step 10 
10 Is the line pressure high? - Go to Step 12  Go to Step 11 
11 Is the line pressure low? - Go to Step 13  -
12
  1. Inspect the following components for high line pressure:
  2. Repair any of the above items as necessary.
Is the repair complete?		 - Go to Step 14  -
13
  1. Inspect the following components for low line pressure:
  2. Repair any of the above items as necessary.
Is the repair complete?		 - Go to Step 14  -
14
  1. Change the AT fluid and filter.

    Refer to Side Cover, Gasket, and Filter Removal

  2. Inspect the AT fluid for correct level.
  3. Add new fluid as necessary.
    4. IMPORTANT: The Clear TAPS function will clear all adapt cells. This may affect transmission performance. The TCM will update the adapt cell values as the vehicle is driven.
  4. Use the scan tool in order to perform the following:
    • Reset oil life monitor to 100%.
    • Clear TAPS.
Did you complete the repair?		 - Go to Step 15  -
15 Perform the following procedure in order to verify the repair:
  1. Select Special Functions.
  2. Select Transmission Output Controls.
  3. Select Clear TAP.
  4. Operate the vehicle under the following conditions:
    • Drive the vehicle in D4 in order to obtain 1-2, 2-3, 3-4 shifts.
    • Shift times must be less than 0.65 second.
  5. Select Specific DTC.
  6. Enter DTC P1811.

Has the test run and passed?		 - Go to Step 16  Go to Step 2 
16 With the scan tool, observe the stored information, capture info. and DTC info.
Does the scan tool display any DTCs that you have not diagnosed?		 - Go to Diagnostic Trouble Code (DTC) List - Vehicle System OK
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