P0751

DTC P0751

Circuit Description
The 1-2 Shift Solenoid (SS) valve controls the fluid flow acting on the 1-2 and 3-4 shift valves. The 1-2 SS valve is a normally-open exhaust valve that is used with the 2-3 SS valve, in order to allow four different shifting combinations.

When the PCM detects a 2-2-3-3 shift pattern, then DTC P0751 sets. DTC P0751 is a type B 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 TFP manual valve position switch DTC P1810, P1815 or P1816.
^ The engine speed is greater than 475 RPM for 5 seconds.
^ 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).
^ The engine torque is 55 - 550 Nm (40 - 405 ft. lbs.).
^ The vehicle speed is greater than 2 km/h (1 mph).

Conditions for Setting the DTC
DTC P0751 sets if both of the following conditions occur twice:

Condition 1
^ The PCM commands first gear for 2 seconds.
^ The estimated gear ratio is 1.2-1.825.
^ All conditions are met for 1.5 seconds.

Condition 2
^ The PCM commands fourth gear for 1 second.
^ The estimated gear ratio is 0.95-1.15.
^ All conditions are met for 2 seconds.

Action Taken When the DTC Sets
^ The PCM illuminates the Malfunction Indicator Lamp (MIL) during the second consecutive trip in which the Conditions for Setting the DTC are met.
^ The PCM commands D2 line pressure.
^ The PCM commands TCC OFF.
^ The PCM inhibits fourth gear in hot mode.
^ The PCM freezes transmission adapt functions.
^ 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 P0751 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.
^ 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 - 3:

Steps 4 - 5:

DTC P0751