P0756

DTC P0756 Shift Solenoid B Performance (Stuck OFF)





Circuit Description
The shift solenoid B is used to control fluid flow acting on the 2-3 shift valves. The solenoid is a normally open exhaust valve that is used with the shift solenoid (A) to allow four different shift combinations.
This DTC detects when there is only a 4-3-3-4 shift pattern depending on the state of the mechanical failure instead of a 1-2-3-4 shift pattern. This is a type B DTC.

Conditions For Setting The DTC
- No ETC DTCs.
- No OSS DTCs P0722 or P0723.
- No TCC solenoid DTC P0742, P1860, P1870.
- No shift solenoid A DTC P0753.
- No shift solenoid B DTC P0758.
- Output speed is greater than 375 rpm.
- Gear range is D4.
- Transmission fluid temperature is between 20° and 130°C (68 and 266°F).
- No range code P0705, P0706.
- No torque code (to be confirmed).
- Engine run for more than 0 seconds and influed cut-off (to be confirmed).

All of the above conditions have been met and the combination of condition 1, 2 occur two consecutive times.

Condition 1:
- 1st gear is commanded for> 1 sec.
- 40 < Engine Torque < 400 ft. lbs..
- Throttle position > 10%.
- -2300 < TCC slip < 200 rpm.
- Transmission out speed > 400 rpm
- Speed ratio > 0.3.
- 0.60 < Modeled Ratio < 1.49 for 1 second.

Condition 2:
- 2nd gear is commanded for > 1 sec.
- 40 < Engine Torque < 400 ft. lbs..
- Throttle position > 10%.
- -8000 < TCC slip < 8000 rpm.
- Speed ratio > 0. 6.
- 0.92 < Modeled ratio < 1.5 for 0.687 seconds.

Action Taken When the DTC Sets
- Maximum line pressure.
- For lamp illuminate, refer to DTC type definition (type B).
- Turn force motor OFF.

Conditions For Clearing The MIL/DTC
- The PCM will turn off the MIL and CHECK TRANS Lamp after three consecutive ignition cycles without a failure reported.
- The DTC can be cleared from the PCM history by using a scan tool.
- The DTC will be cleared from history when the vehicle has achieved 40 warm-up cycles without a failure reported.
- The PCM will cancel the DTC default actions when the fault no longer exists and the ignition is cycled "off" long enough to power down the PCM.

Diagnostic Aids
- Verify that the transmission meets the specifications in the 4L30-E shift speed chart.
- Other internal transmission failures may allow more than one shift to occur.





Step 1 - 4





Step 5

Test Description
The numbers below refer to the step numbers on the diagnostic chart:
2. This test checks the function of the range switch (mode switch).
3. This test checks for selected gear ratio vs. a ratio not obtainable under normal driving conditions.