For 1990-2009 cars
Automatic Transmission Components
Automatic Transmission Controls Schematics
OBD II Symbol Description Notice

### Circuit Description

The transmission pressure is modified by an adaptive modifier which controls the shift execution time. This test checks 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.

If the PCM detects the counter reaching two, then DTC P1811 sets. DTC P1811 is a type D DTC.

### Conditions for Setting the DTC

Any combination of the following fail cases are true two times within one ignition cycle.

#### Case 1

• | The 1-2 shift is longer than 0.65 seconds.

• | The 1-2 shift adapt has reached its limit.

#### Case 2

• | The 2-3 shift is longer than 0.65 seconds.

• | The 2-3 shift adapt has reached its limit.

#### Case 3

• | The 3-4 shift is longer than 0.65 seconds.

• | The 3-4 shift adapt has reached its limit.

### Action Taken When the DTC Sets

• | The PCM commands maximum line pressure.

• | The PCM disables shift adapts.

• | The PCM does not illuminate the Malfunction Indicator Lamp (MIL).

### Conditions for Clearing the DTC

• | A scan tool can clear the DTC from the PCM history. The PCM clears the DTC from the PCM history if the vehicle completes 40 warm-up cycles without a failure reported.

• | The PCM cancels the DTC default actions when the fault no longer exists and the ignition is OFF long enough in order to power down the PCM.

### Diagnostic Aids

• | Inspect for possible vehicle overloading, exceeding trailer towing limit, or towing in overdrive.

• | Ensure that the PCM has the latest update.

• | If you performed a transmission overhaul, use the scan tool to clear all adapts.

### Test Description

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

1. This step inspects components located within the valve body, if the fluid pressure gauge readings do not match the commanded PC Sol. Valve current to line pressure located in the value column.

2. 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.

3. 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.

4. 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.

#### DTC P1811 Maximum Adapt and Long Shift

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Was the Powertrain On-Board Diagnostic (OBD) System Check performed? | -- | Go to Step 2 | Go to Powertrain On Board Diagnostic (OBD) System Check in Engine Controls
2 | Have you performed the transmission fluid checking procedure? | -- | Go to Step 3 | Go to Transmission Fluid Check
3 |

1. Install the Scan Tool .
2. Turn the ignition switch to the Run position.
3. The engine is not running.

Important: Before clearing the DTCs, use the Scan Tool in order to record the Freeze Frame for reference.

4. Record the Freeze Frame and Failure Records, then clear the DTCs.

Are any of the following DTCs set: P0120, P0121, P0122, P0123, P1121, P1122, P1524, P0502, P0503, P0711, P0712 or P0218?

--

Go to Step 4

Go to Step 5

4 | Diagnose those DTCs first. Is the diagnosis and repair complete? | -- | Go to Step 14 | --
5 |

1. Use the Scan Tool snapshot mode in order to record the shift times.
2. Drive the vehicle in D4 in order to obtain a 1-2, a 2-3, and 3-4 upshift.
3. Record the shift times.

Did all the shift times exceed the specified value?

0.65 seconds

Go to Step 6

Go to Step 8

6 | Perform the line pressure check. Refer to Line Pressure Check . Is the line pressure within specifications? | -- | Go to Diagnostic Aids | Go to Step 7
7 | Inspect the transmission for the following conditions:

• | Clogged fluid filter

• | Out-of-position fluid filter

• | Internal fluid passage leaks

• | Casting porosity or damage

• | Damaged gasket or spacer plate

• | Out-of-position gasket or spacer plate

• | Contaminated PC Sol. Valve

• | Damaged PC Sol. Valve

• | Stuck PC Sol. Valve

• | Stuck pressure regulator valve train

• | Leaking pressure regulator valve train

• | Stuck torque signal valve train

• | Leaking torque signal valve train

• | Leaking oil pump

• | Damaged oil pump

• | Inadequate oil pump suction

• | Oil pump cavitation

Refer to Transmission Overhaul in the 4T65-E Section of the Transmission Unit Repair Manual.

Did you find and correct the condition?

--

Go to Step 14

--

8 | Did the 1-2 shift time exceed the specified value? | 0.65 seconds | Go to Step 9 | Go to Step 10
9 |

1. Inspect the 1-2 shift circuit for the following conditions:

• | Leaking 1-2 accumulator piston seals

• | Rolled 1-2 accumulator piston seals

• | Cut 1-2 accumulator piston seals

• | 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 pistons

• | Leaking driven sprocket support seals

• | Damaged driven sprocket support seals

• | Internal fluid passage leaks

• | Casting porosity or damage

• | Damaged gasket or spacer plate

• | Out-of-position gasket or spacer plate

• | Slipping forward band

• | Damaged input sprag clutch (not holding)

• | 1-2 support roller clutch damaged (not holding)

2. Repair the 1-2 shift circuit.

Refer to Transmission Overhaul in the 4T65-E Section of the Transmission Unit Repair Manual.

Did you find and correct the condition?

--

Go to Step 14

--

10 | Did the 2-3 shift time exceed the specified value? | 0.65 seconds | Go to Step 11 | Go to Step 12
11 |

1. Inspect the 2-3 shift circuit for the following conditions:

• | Leaking 2-3 accumulator piston seals

• | Rolled 2-3 accumulator piston seals

• | Cut 2-3 accumulator piston seals

• | Leaking 3rd clutch piston seals

• | Rolled 3rd clutch piston seals

• | Cut 3rd clutch piston seals

• | Burned 3rd clutch plates

• | Damaged 3rd clutch plates

• | Broken 3rd clutch springs

• | Out-of-position 3rd clutch springs

• | Damaged 3rd clutch pistons

• | Leaking driven input shaft seals

• | Damaged driven input shaft seals

• | Damaged driven sprocket support bushing

• | Damaged 3rd sprag clutch (not holding)

• | Internal fluid passage leaks

• | Casting porosity or damage

• | Damaged gasket or spacer plate

• | Out-of-position gasket or spacer plate

2. Repair the 2-3 shift circuit.

Refer to Transmission Overhaul in the 4T65-E Section of the Transmission Unit Repair Manual.

Did you find and correct the condition?

--

Go to Step 14

--

12 | Did the 3-4 shift time exceed the specified value? | 0.65 seconds | Go to Step 13 | --
13 |

1. Inspect the 3-4 shift circuit for the following conditions:

• | Leaking 3-4 accumulator piston seals

• | Rolled 3-4 accumulator piston seals

• | Cut 3-4 accumulator piston seals

• | Leaking 4th clutch piston seals

• | Rolled 4th clutch piston seals

• | Cut 4th clutch piston seals

• | Burned 4th clutch

• | Out-of-position 4th clutch

• | Damaged 4th clutch

• | Slipping 4th clutch

• | Internal fluid passage leaks

• | Casting porosity or damage

• | Damaged gasket or spacer plate

• | Out-of-position gasket or spacer plate

• | Slipping 3rd clutch

• | Damaged 4th clutch piston

• | Seized 4th clutch piston

• | Damaged 4th clutch piston

• | Cracked 4th clutch piston

• | Leaking 4th clutch piston

2. Repair the 3-4 shift circuit.

Refer to Transmission Overhaul in the 4T65-E Section of the Transmission Unit Repair Manual.

Did you find and correct the condition?

--

Go to Step 14

--

14 | In order to verify your repair, perform the following procedure:

1. Select DTC.
2. Select Clear Info.
3. Operate the vehicle under the following conditions:

• | Drive the vehicle in D4 in order to obtain 1-2, 2-3 and 3-4 upshifts.

• | Shift times must be less than 0.65 seconds.

4. Select Specific DTC.
5. Enter DTC P1811.

Has the test run and passed?

--

System OK

Go to Step 1