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 1-2-2-1 shift pattern, then DTC P0757 sets. DTC P0757 is a type A DTC.
Conditions for Running the DTC
- No TP sensor DTCs P0122 or P0123.
- No VSS assembly DTCs P0502 or P0503.
- No 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 TFP manual valve position switch DTC P1810.
- No TCC PWM solenoid valve DTC P1860.
- 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 1 second.
- The estimated gear ratio is 1.6 to 1.8.
- The torque converter efficiency is greater than 0.5.
- The engine torque is 50-400 lb ft.
- All conditions are met for 2 seconds.
- Condition 2
- The PCM commands fourth gear for 1 second.
- The estimated gear ratio is 1.8 to 3.3.
- The torque converter efficiency is greater than 0.5.
- The engine torque is 0-400 lb ft.
- 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.