P0755 – Shift Solenoid B Malfunction indicates that the Transmission Control Module (TCM) or Powertrain Control Module (PCM) has detected a fault in the electrical or hydraulic operation of Shift Solenoid “B.” This solenoid controls gear changes inside the automatic transmission by regulating fluid pressure. When it fails, you may experience harsh shifting, slipping, or being stuck in one gear. This guide explains what P0755 means, what symptoms to expect, the most common causes, how to diagnose it, and the best repair options.
What Does P0755 Mean?
P0755 is a powertrain OBD-II code that appears when the TCM detects abnormal electrical activity or improper hydraulic response from Shift Solenoid B. The solenoid may be stuck, shorted, open, clogged, or receiving incorrect voltage. Since solenoid B is part of the valve body assembly, the fault affects gear selection, line pressure, and shift timing.
This code typically appears on vehicles with automatic transmissions such as Chrysler, Ford, Toyota, Nissan, Honda, and many others. Depending on the transmission design, the vehicle may enter limp mode to prevent damage.
Quick Reference
- OBD-II Family: P-Code (Powertrain)
- Scope: Generic
- System: Automatic Transmission / Shift Control
- Difficulty Level: Moderate–Advanced
- Estimated Repair Cost: €120–€950+
- Last Updated: 28 November 2025
Real-World Example / Field Notes
A Dodge Charger arrived in limp mode, stuck in 2nd gear. Scanning revealed P0755. Electrical testing showed the Shift Solenoid B circuit was open due to a corroded connector on the transmission. Cleaning the connector and repairing the harness restored normal shifting and cleared the code.
Another case involved a Toyota Camry with harsh 1–2 upshifts. Fluid analysis revealed heavily contaminated ATF and metal shavings clogging the solenoid’s internal screen. After flushing the fluid and replacing the solenoid pack, the transmission shifted smoothly again.
Symptoms of P0755 – Shift Solenoid B Malfunction
- Harsh or delayed shifting: Especially during 1–2 or 2–3 upshifts.
- Stuck in limp mode: Transmission locked in 2nd or 3rd gear.
- Gear slipping: Engine revs increase without corresponding acceleration.
- Poor fuel economy: Due to incorrect gear selection.
- Check engine light: P0755 stored, sometimes accompanied by other solenoid codes.
- Overheating transmission: Caused by fluid pressure issues.
Common Causes of P0755
Most Common Causes
- Failed Shift Solenoid B
- Clogged or restricted solenoid screen
- Dirty, burnt, or low transmission fluid
- Damaged wiring or corroded transmission connector
- Internal valve body faults (sticking valves)
Less Common Causes
- TCM/PCM internal driver failure
- Mechanical transmission damage
- Pressure control solenoid issues
- Incorrect ATF type causing pressure problems
- Fluid contamination from clutch wear debris
Diagnosis: Step-by-Step Guide
P0755 diagnosis requires both electrical and hydraulic checks since the solenoid relies on the correct voltage and fluid flow.
Tools You’ll Need
OBD-II scan tool, multimeter, wiring diagrams, ATF dipstick (if applicable), pressure gauge (optional), and basic hand tools.
- Check ATF level and condition: Low or burnt fluid can cause solenoid malfunction.
- Scan transmission data: Check for additional solenoid or pressure codes.
- Inspect harness and connectors: Look for corrosion, broken wires, or fluid leaks.
- Test solenoid resistance: Compare ohm readings to manufacturer specs.
- Command solenoid ON/OFF: Using a scan tool, verify response and listen for clicks.
- Check for proper voltage supply: Use a multimeter to verify power and ground.
- Perform ATF pressure test: Identify hydraulic restrictions or low line pressure.
- Drop transmission pan: Inspect for metal shavings or debris.
- Inspect valve body: Look for sticking valves or restricted passages.
- Test or replace solenoid: Install a known-good unit if solenoid failure is suspected.
Pro Tip: If the code returns immediately after clearing it, the problem is usually electrical. If symptoms worsen as the transmission heats up, the issue is often hydraulic.
Possible Fixes & Repair Costs
- Replace Shift Solenoid B: €120–€350
- Clean transmission connectors / repair wiring: €40–€150
- Transmission fluid + filter change: €80–€200
- Replace valve body assembly: €300–€950+
- Rebuild or replace transmission (severe cases): €1,000–€3,500+
- Replace or reprogram TCM/PCM: €150–€400+
Can I Still Drive With P0755?
You can drive briefly, but it is not recommended. Limp mode, slipping, and harsh shifts can cause internal transmission damage. Continued driving may overheat the ATF, burn clutch packs, or clog the valve body. Address the issue as soon as possible to avoid costly repairs.
Related Codes
- P0750 – Shift Solenoid A Malfunction
- P0760 – Shift Solenoid C Malfunction
- P0770 – Shift Solenoid E Malfunction
- P0715 – Input/Turbine Speed Sensor
- P0795 – Pressure Control Solenoid B
Key Takeaways
- P0755 indicates an electrical or hydraulic malfunction in Shift Solenoid B.
- Dirty or low ATF, wiring issues, or a failed solenoid are the most common causes.
- Transmission may enter limp mode for protection.
- Early diagnosis prevents costly transmission damage.
FAQ
Does P0755 always mean the solenoid is bad?
No. Wiring issues and contaminated ATF can also trigger the code.
Can old transmission fluid cause P0755?
Yes. Dirty fluid can clog the solenoid or restrict hydraulic passages.
What happens if I ignore this code?
Shifts will worsen, and the transmission may suffer permanent damage.
Is it safe to drive in limp mode?
Only short distances. Limp mode prevents damage but is not safe for long-term use.
Do I need a full transmission rebuild?
Only if internal damage or repeated contamination is found. Many cases are solved with wiring repair or replacing the solenoid.