P0751

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 2-3 only or a 1-4 only shift pattern depending on the state of the mechanical failure. This is a type "B" DTC.

Conditions For Setting The DTC
- No TP DTCs P0122 or P0123.
- No OSS DTCs P0722 or P0723.
- No TCC solenoid DTC P0742, P1860.
- No shift solenoid A DTC P0753.
- No shift solenoid B DTC P0758.
- Gear range is D4.
- Vehicle speed is greater than 10 km/h (6.25 mph).
- Transmission temperature is between 20° and 125°C (68° and 257°F).
All the above conditions have been met and the combination of conditions 1, 2, 3, and 4 or 1, 2, 3, and 5 occur two consecutive times.

Condition 1:
- Commanded 1-2 shift.
- TP angle is between 10 and 60%.
- TP angle is constant within +/-3%.
- Vehicle speed is between 18 and 50km/h (11 and 31 mph).
- Within 2.2 seconds, the engine speed in 2nd gear must be 100 rpm greater than the last speed in 1st gear.

Condition 2:
- Commanded 2-3 shift.
- TP angle is between 13 and 60%.
- TP angle is constant within +/-5%.
- Vehicle speed is between 30 and 88 km/h (20 and 45 mph).
- Within 2 seconds, the engine speed in 3rd gear must be 64 rpm less than the last speed in 2nd gear.

Condition 3:
- Commanded 3-4 shift.
- TP angle is between 7 and 60%.
- TP angle is constant within +/-5%.
- Vehicle speed is between 40 and 140 km/h (25 and 87 mph).
- Within 0.7 seconds, the engine speed in 4th gear must be -60 rpm greater than the last speed in 3rd gear.

Condition 4:
- Commanded 4th gear.
- TCC is on.
- TP angle is between 13 and 60%.
- Speed ratio is between 0.85 and 1.2 (speed ratio is engine speed + output speed).
- TCC slip speed is between 100 and 2000 rpm for 3 seconds.

Condition 5:
- Commanded 4th gear.
- TCC is on.
- TP angle is between 13 and 60%.
- Speed ratio is between 0.5 and 0.85.
- TCC slip speed is between -50 and 500 rpm for 3 seconds.

Action Taken When the DTC Sets
- Maximum line pressure.
- The PCM will illuminate the Malfunction Indicator Lamp (MIL) and CHECK TRANS. Lamp.

Conditions For Clearing The The MIL/DTC
- The PCM will turn oft 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 warmup 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 cause more than one shift to occur.
- A shift solenoid A performance problem could set a shift solenoid B DTC P0756 or a transmission component slipping DTC P1870.

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





DTC P0751 Shift Solenoid A Performance Without Input Speed