P0757

DTC P0757

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 4 different shifting combinations.

When the powertrain control module (PCM) detects a 1-2-2-1 shift pattern, then DTC P0757 sets. DTC P0757 is a type A DTC.

Conditions for Running the DTC
^ No throttle position (TP) sensor DTCs P0122 or P0123.
^ No vehicle speed sensor (VSS) assembly DTCs P0502 or P0503.
^ No torque converter clutch (TCC) solenoid valve DTC P0740.
^ No TCC stuck ON DTC P0742.
^ No 1-2 SS valve DTC P0753.
^ No 2-3 SS valve DTC P0758.
^ No 3-2 SS valve assembly DTC P0785.
^ No transmission fluid pressure (TFP) manual valve position switch DTC P1810.
^ The engine speed is greater than 450 RPM for 5 seconds.
^ The engine is not in fuel cutoff.
^ The gear range is D4.
^ The TP angle is greater than 10 percent.
^ The transmission fluid temperature is 20-130°C (68-266°F).
^ The system voltage is 10-18 volts.
^ The transmission output speed is 150 RPM or greater.

Conditions for Setting the DTC
DTC P0757 sets if both of the following conditions occur:

Condition 1
^ The PCM commands third gear for one second.
^ The estimated gear ratio is 1.6 to 1.8.
^ The torque converter efficiency is greater than 0.5.
^ The engine torque is 67-542 Nm (50-400 ft. lbs.).
^ All conditions are met for 2 seconds.

Condition 2
^ The PCM commands fourth gear for one second.
^ The estimated gear ratio is 1.8 to 3.3.
^ The torque converter efficiency is greater than 0.5.
^ The engine torque is 0-542 Nm (0-400 ft. lbs.).
^ All conditions are met for 2 seconds.

Action Taken When the DTC Sets
^ The PCM illuminates the malfunction indicator lamp (MIL).
^ The PCM commands 3rd gear only.
^ The PCM commands maximum line pressure.
^ The PCM inhibits TCC engagement.
^ The PCM inhibits fourth gear if the transmission is in hot mode.
^ 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 P0757 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.

Test Description
The numbers below refer to the step numbers 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 - 4:

DTC P0757