Transmission · Powertrain · generic (SAE-defined)
P0755: Shift Solenoid "B"
P0755 means the transmission computer has detected a general fault with shift solenoid B, one of the valves it uses to direct fluid and select gears.
Standard title per SAE J2012 / ISO 15031-6 · Updated 2026-11-07 · By CarWhere Research
How P0755 sets
The powertrain or transmission control module (PCM/TCM) uses combinations of shift solenoid states to select gears and monitors each solenoid's circuit. When solenoid B's circuit does not respond as expected for the commanded state, the module sets P0755. The gears controlled by solenoid B and the exact test logic depend on the manufacturer and transmission model.
Common causes of P0755
Roughly most likely first; the actual cause depends on the vehicle and needs testing to confirm.
- Failed shift solenoid B
- Wiring or connector fault in the solenoid B circuit
- Internal harness damage
- Low or contaminated fluid
- Loss of solenoid power supply
- PCM/TCM fault (less common)
P0755 symptoms
- Check engine light on
- Transmission holds one gear or enters limp mode
- Skipped or erratic shifts
- Harsh or delayed engagement
- Lower fuel economy
How P0755 is diagnosed
- Check fluid level and condition.
- Scan all codes and review freeze frame data.
- Determine which gears solenoid B affects on this transmission.
- Inspect connectors and wiring for damage, corrosion, or fluid intrusion.
- Measure solenoid B resistance and test circuit continuity and shorts.
- Command solenoid B with a bidirectional scan tool and observe its response.
Typical fixes for P0755
- Repair wiring or connector damage
- Replace shift solenoid B or the solenoid pack
- Replace the internal transmission harness
- Service the transmission fluid and filter
- Repair or replace the PCM/TCM if confirmed
Replace parts only after testing confirms the cause — a code names the circuit or condition that failed a check, not necessarily the faulty part. We don’t publish per-repair prices; for what households actually spend on upkeep, see car repair costs.
Manufacturer notes
Shift solenoid B's role differs by transmission; check factory service information for the specific vehicle.
Related codes & warning lights
P0755 FAQ
What does code P0755 mean?
P0755 means the transmission computer has detected a general fault with shift solenoid B, one of the valves it uses to direct fluid and select gears. The standard definition is "Shift Solenoid "B"."
Can I drive with a P0755 code?
Keep driving to a minimum. Shift solenoid B problems can cause missed gears or limp mode, and running a transmission with improper shifts can damage clutches.
Is shift solenoid B the same on every car?
No. The letter is assigned by each manufacturer, so solenoid B on one transmission may control completely different gears than on another.
Does P0755 require a transmission rebuild?
Usually not. Many cases are resolved with a solenoid, harness, or connector repair, although damage from prolonged slipping can change that.
Keep researching
More transmission codes
Sources
- SAE J2012 — Diagnostic Trouble Code Definitions (standard code titles)
- ISO 15031-6 — Road vehicles: communication between vehicle and external equipment for emissions-related diagnostics, Part 6: Diagnostic trouble code definitions
- U.S. EPA — Vehicle Emissions Inspection and Maintenance (I/M) programs
- U.S. EPA, 40 CFR 86.1806-17 — Federal onboard diagnostics requirements for light-duty vehicles
General information written by CarWhere Research, not a diagnosis of your vehicle. Manufacturers can add their own sub-definitions and test conditions; confirm with the factory service information for your year, make and model. Before paying for a repair, check NHTSA for open recalls and your warranty booklet: federal law requires an emissions warranty on major emission-control parts such as the catalytic converter and engine computer.