OBD-II Code P0755 — What It Means & How to Fix It

What Does This Error Mean?

P0755 means Shift Solenoid B has a malfunction. Shift solenoids control the hydraulic fluid flow inside the automatic transmission, engaging the correct gears. Solenoid B handles different gear combinations than Solenoid A — often second gear and higher. When it fails, the transmission may get stuck in a gear, slip, or shift harshly. Diagnosis and repair are similar to P0750 — check fluid, test the solenoid electrically, and replace if faulty.

Affected Models

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

Common Causes

Faulty shift solenoid B with an open or shorted coil
Clogged solenoid orifice from dirty or contaminated transmission fluid
Damaged or corroded wiring between the solenoid and the TCM
Low transmission fluid causing insufficient hydraulic pressure
Worn valve body bore around solenoid B reducing hydraulic sealing

How to Fix It

Check transmission fluid level and condition before anything else. Bad fluid is the most common cause of solenoid failure and clogging.

Use the correct fluid type for your transmission — wrong fluid type can damage solenoids and seals.
Drop the transmission pan to access the valve body. Locate shift solenoid B using your repair manual diagram.

Take photos of the solenoid positions before removing anything so you can reinstall everything correctly.
Test solenoid B with a multimeter. Resistance should be 10 to 30 ohms. Replace it if it reads open or shorted.

Apply 12V briefly to confirm the mechanical plunger clicks. No click with correct resistance can mean a stuck plunger.
Inspect the valve body surface around the solenoid bore for wear or scoring. A worn bore allows fluid to bypass the solenoid and causes incorrect pressure regardless of solenoid operation.

Worn valve body bores require valve body replacement — solenoid replacement alone will not fix the problem in this case.
Replace the solenoid, install fresh fluid and a new filter, and reinstall the pan. Clear the code and test drive through all gear ranges.

Watch for smooth 1-2-3-4+ shifts and no slipping. If problems persist, the valve body or clutch packs may need attention.

When to Call a Professional

Solenoid replacement with fluid and filter service costs $300 to $600 at a shop. Individual solenoids are $30 to $80. Solenoid packs are $80 to $200. If the valve body is worn, valve body replacement costs $300 to $700 for the part plus labor. Transmission rebuild costs $2,500 to $4,500 if extensive internal damage is found.

Frequently Asked Questions

How is P0755 different from P0750?

Both are shift solenoid failures, but they affect different solenoids. P0750 is Solenoid A — usually involved in lower gear engagement. P0755 is Solenoid B — usually involved in higher gear combinations. The diagnosis process is the same, but the specific gear affected differs.

Can I drive with P0755?

Short distances only. With a failed shift solenoid, the transmission may not shift through all gears. You could be stuck in one gear, or experience slipping. Driving long-term with this condition accelerates transmission wear.

Should I replace all solenoids at once?

If the others are original and the transmission has high mileage, replacing the whole solenoid pack makes sense. The labor cost to access them is the expensive part — the extra parts cost is small in comparison. If the transmission has low mileage and only B has failed, replace just B.