OBD-II Code P0750 — What It Means & How to Fix It

What Does This Error Mean?

P0750 means Shift Solenoid A has a malfunction. Shift solenoids are electrically operated valves inside the transmission. They direct hydraulic fluid to engage the correct clutch packs and bands for each gear. When Solenoid A fails or has a circuit problem, certain gear changes may not work correctly. You may notice the transmission stuck in one gear, slipping, or harsh shifts.

Affected Models

All vehicles 1996+ with automatic transmission
Common in Honda and Acura vehicles
Common in Toyota vehicles
Common in GM vehicles
Common in Ford vehicles

Common Causes

Faulty shift solenoid A that has failed electrically (open or shorted coil)
Damaged or corroded wiring to the solenoid
Clogged solenoid caused by transmission fluid contamination
Low or dirty transmission fluid reducing hydraulic pressure to the solenoid
Faulty transmission control module output for solenoid A

How to Fix It

Check the transmission fluid first. Low or burnt fluid (dark, with a burnt smell) can cause solenoid problems. If the fluid is bad, change it before further diagnosis.

Fluid contamination can clog solenoid passages. Sometimes a fluid and filter change resolves P0750 if the solenoid is clogged rather than electrically failed.
Locate the shift solenoid A. Drop the transmission pan to access the valve body where solenoids are mounted. Identify the solenoid labeled A in your repair manual diagram.

Solenoid labeling (A, B, C, etc.) varies by manufacturer. Your repair manual will identify which solenoid is A.
Test solenoid A with a multimeter. Measure resistance across its terminals. Most shift solenoids read 10 to 30 ohms. An open circuit (no reading) or a short (near zero) means the solenoid has failed.

You can also apply 12V briefly to the solenoid and listen for a click — this confirms the mechanical plunger is moving.
Inspect the wiring from the solenoid connector to the TCM. Look for damage, corrosion, or looseness along the external portion of the harness.

The internal wiring harness inside the transmission can also fail. Replacement harnesses are available for common transmissions.
Replace the faulty solenoid. Change the fluid and filter at the same time. Clear the code and test drive to verify smooth shifting through all gears.

Allow several miles of driving for the TCM to relearn shift adaptation values after solenoid replacement.

When to Call a Professional

Shift solenoid replacement is a moderate repair. Individual solenoids cost $30 to $80. Solenoid packs cost $80 to $200. The solenoids are usually inside the transmission pan — a fluid and filter change is done at the same time. Labor at a shop is $200 to $400 including fluid service. Total repair is typically $300 to $600 at a shop.

Frequently Asked Questions

What gears does Shift Solenoid A control?

It varies by manufacturer and transmission type. Generally, Solenoid A controls lower gear engagement — often 1st and 2nd gear on many 4-speed automatics. Your repair manual will specify exactly which gear combinations require Solenoid A to be on or off.

Can I clean a shift solenoid instead of replacing it?

Sometimes cleaning with automatic transmission fluid or a solenoid-safe cleaner will free a stuck plunger. However, if the solenoid's coil has failed electrically, cleaning will not help. Cleaning is worth trying before replacement if the solenoid tests at the correct resistance.

Will P0750 cause the car to fail inspection?

Yes — any active check engine light will cause an automatic emissions test failure in most states. Have P0750 diagnosed and repaired, then clear the code and complete a full drive cycle before your inspection.