P0750 indicates an electrical malfunction with Shift Solenoid A, the on/off valve that directs transmission fluid to control a specific gear shift. The PCM/TCM has detected an open, short, or performance problem in that solenoid's circuit.
The solenoid coil can open internally, short to ground, or its mechanical valve can stick, preventing the PCM from commanding the intended shift.
Chafed, broken, corroded, or poorly connected wires between the PCM/TCM and the transmission can cause an open or short that sets P0750.
Incorrect fluid level, degraded fluid, or debris can restrict solenoid operation or cause the valve to stick intermittently.
Wear, deposits, or a damaged valve body can prevent the solenoid from properly controlling hydraulic pressure.
Rarely, the control module's solenoid driver circuit fails; this should only be considered after the solenoid, wiring, and fluid have been verified.
No. Wiring, connector, and fluid-related faults are very common, so the solenoid should be electrically tested before it is condemned.
The transmission may enter limp mode, which limits speed and acceleration. Continued driving can increase wear, so diagnosis is recommended promptly.
Usually no. PCM/TCM failure is one of the least likely causes of this code. Verify the solenoid, wiring, connectors, and fluid first; replace the control module only if its output driver is proven faulty.
It can help if contaminated or degraded fluid is causing the solenoid valve to stick. It will not fix an electrically open or shorted solenoid, or damaged wiring.