P0756

DTC P0756

Circuit Description
The 2-3 Shift Solenoid (SS) valve controls the fluid flow acting on the 2-3 shift valves. The 2-3 SS valve is a normally-open exhaust valve that is used with the 1-2 SS valve, in order to allow four different shifting combinations. When the PCM detects a 4-3-3-4 shift pattern, then DTC P0756 sets. DTC P0756 is a type A DTC.

Conditions for Running the DTC
^ No VSS assembly DTCs P0502 or P0503.
^ No 1-2 SS valve DTC P0973 or P0974.
^ No 2-3 SS valve DTC P0976 or P0977.
^ No 3-2 SS valve assembly DTC P0787 or P0788
^ The engine speed is greater than 475 RPM for 5 seconds.
^ The engine is not in fuel cutoff.
^ The gear range is D4, D3, D2 or D1.
^ The TP angle is greater than 10 percent.
^ The transmission fluid temperature is 20 - 130°C (68 - 266°F).

Conditions for Setting the DTC
DTC P0756 sets if both of the following conditions occur:

Condition 1
^ The PCM commands first gear for 3 seconds.
^ The estimated gear ratio is 0 to 1.
^ The engine torque is 225 - 675 Nm (165 - 295 ft. lbs.).
^ All conditions are met for 3 seconds.

Condition 2
^ The PCM commands second gear for 3 seconds.
^ The estimated gear ratio is 0.9 to 1.2.
^ The engine torque is 65 - 550 Nm (48 - 406 ft. lbs.).
^ All conditions are met for 3 seconds.

Action Taken When the DTC Sets
^ The PCM illuminates the Malfunction Indicator Lamp (MIL).
^ The PCM commands third gear only.
^ The PCM commands maximum line pressure.
^ The PCM inhibits TCC engagement.
^ The PCM freezes shift adapts from being updated.
^ The PCM records the operating conditions when the Conditions for Setting the DTC are met.
^ The PCM stores this information as Freeze Frame and Failure Records.
^ The PCM stores DTC P0756 in PCM history.

Conditions for Clearing the MIL/DTC
^ The PCM turns OFF the MIL during the third consecutive trip in which the diagnostic test runs and passes.
^ A scan tool can clear the MIL/DTC.
^ The PCM clears the DTC from PCM history if the vehicle completes 40 warm-up cycles without an emission- related diagnostic fault occurring.
^ The PCM cancels the DTC default actions when the fault no longer exists and/or the ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
^ Verify that the transmission meets the specifications in the Shift Speed table.
^ Other internal transmission failures may cause more than one shift to occur.
^ Refer to the Shift Solenoid Valve State and Gear Ratio table.

Test Description
The number below refers to the step number on the diagnostic: table.
2. This step tests that the PCM commanded all shifts, that all shift solenoid valves responded correctly, but that all the shifts did not occur.

Steps 1 - 2:

Steps 3 - 5:

DTC P0756