P0756

DTC P0756





Circuit Description
The 2-3 Shift Solenoid (SS) valve is a normally-open exhaust valve that, in conjunction with the 1-2 Shift Solenoid (SS) valve, allows four different shifting combinations. The 2-3 SS valve is attached to the control valve body, within the transmission.
The PCM monitors the actual gear ratio, and compares the actual gear ratio with the commanded gear ratio. DTC P0756 sets under two conditions:
- A stuck ON 2-3 SS valve
- A stuck ON 2-3 shift valve

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 TP DTCs P0121, P0122 or P0123.
- No VSS DTCs P0502 or P0503.
- No AT ISS DTCs P0716 or P0717.
- No shift solenoid electrical DTCs P0753 or P0758.
- No TFP manual valve position switch DTC P1810.
- The system voltage is 8-18 volts.
- The engine is running.
- The TFP manual valve position switch is not indicating Park, Reverse, or Neutral.
- The transmission fluid temperature is 20 - 130°C (68 - 266°F).
- The TP is greater than 8 percent.
- The input speed is greater than 150 RPM.
- The vehicle speed is greater than 8 km/h (5 mph).
- The engine torque is greater than 27 Nm (20 ft. lbs.).

Conditions for Setting the DTC
- The PCM commands 1st gear and the gear ratio is 0.61:1 - 0.72:1, 4th gear, for 4 seconds.
- The PCM commands 2nd gear and the gear ratio is 0.91:1 - 1.07:1, 3rd gear, for 4 seconds.

Action Taken When the DTC Sets
- The PCM illuminates the Malfunction Indicator Lamp (MIL).
- The PCM commands an immediate landing to 2nd gear.
- The PCM commands maximum line pressure.
- The PCM inhibits TCC engagement.
- 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 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 ignition switch is OFF long enough in order to power down the PCM.

Diagnostic Aids
- If you clear DTC P0756, and then cannot reset DTC P0756, inspect for the following conditions:
- Fluid contamination
- Plugged fluid circuits
- Restricted fluid circuits

Test Description
The numbers below refer to the step numbers on the diagnostic table.
3. This step verifies a 4-3-3-4 shift pattern.
4. This step tests for a mechanical or hydraulic condition causing the 2-3 SS valve to be stuck ON, or the circuit to be applied.