P1811

Diagnostic Chart:

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.

7. 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.

9. 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.

11. 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.

13. 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.