Summary
P0750 indicates a fault in shift solenoid A — the first shift solenoid in the transmission's hydraulic control system. The TCM detected an electrical or functional problem with this solenoid, which controls fluid flow for gear engagement (typically 1st and 2nd gear shifts on most transmissions). The most common causes are a failed solenoid (40%), wiring issues (20%), and low or contaminated transmission fluid (20%). When solenoid A fails, expect stuck gears, no 1-2 shift, or limp mode.
Severity: Moderate to High — directly affects gear shifting
Safe to drive: Drive with caution — may be stuck in one gear (limp mode)
Repair cost: $15–$900+ depending on cause
DIY difficulty: Moderate to Advanced
What does P0750 mean?
Automatic transmissions use a set of shift solenoids — electrically controlled hydraulic valves — to direct fluid flow and engage different gear sets. Shift solenoid A (also called solenoid 1 or SS1 on some platforms) is typically responsible for controlling the 1-2 shift and plays a role in other gear combinations depending on the transmission design.
When the TCM commands solenoid A on or off and the electrical feedback doesn't match expectations — wrong current draw, open circuit, short to ground, or short to power — it sets P0750. Some versions of this code are purely electrical (circuit fault), while on other systems P0750 can also set for performance issues (the solenoid works electrically but doesn't produce the expected shift result).
The practical result: the transmission can't make one or more shifts correctly. Common symptoms include being stuck in one gear from startup, delayed or missing 1-2 shift, harsh engagement, or the transmission defaulting to limp mode. On many vehicles, limp mode locks the transmission in 2nd or 3rd gear with no further shifting.