P0751

Part 1 Of 3:

Part 2 Of 3:

Part 3 Of 3:

Inspection Procedure


Circuit Description
The shift solenoid A is used to control fluid flow acting on the 1-2 and 3-4 shift valves. The solenoid is a normally close exhaust valve that is used with the shift solenoid B to allow four different shifting combinations.
The DTC detects a 1-1-4-4 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.
- Gear range is D4.
- Output speed is greater then 375 rpm.
- Transmission temperature is between 20° and 125°C (68° and 257°F).
- No range code P0705, P0706.
- No torque code (to be confirmed).
- Engine run for more than 0 seconds and not influed cut-off (to be confirmed).
All the above conditions have been met and the combination of conditions 1, 2 occur two consecutive times.

Condition 1:
- 2nd gear is commanded for >1 second
- 40 < Engine Torque < 400 ft. lbs.
- Throttle position >10%
- 800 < TCC slip < 4000 rpm
- Speed ratio > 0.6
- 2.75 < Modeled Ratio < 3.2 for 1 seconds

Condition 2:
- 3rd gear is commanded for 1 > sec
- 40 < Engine Torque < 400 ft. lbs.
- Throttle position > 10%
- -8000< TCC slip < 8000 rpm
- Speed ratio > 0.45
- 0.62 < Modeled Ratio < 0.92 for 3 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 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
- Verity that the transmission meets the specifications in the 4L30-E shift speed chart.
- Other internal transmission failures may cause more than one shift to occur.

Test Description
The numbers 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 that the scan tool commanded all shifts, all shifts solenoids responded correctly, but all the shifts did not occur.