What it means
Shift solenoid B appears stuck on. The code does not identify the cause or which gears the solenoid controls.
At a glance
- Usually lights the check-engine light
How it works
Shift solenoid B controls hydraulic flow inside the transmission under commands from the control module. The module compares the commanded state with transmission operation and sets this code when solenoid B appears to remain on; the code alone does not identify which gears it controls or why it is stuck.
Common causes
Most likely first.
- Solenoid stuck open
- Carbon or debris buildup preventing free movement
- Component wear with age - mechanical play
Symptoms
- Check engine or transmission warning light on
- Harsh, delayed, or missing shifts
- Possible limp mode (locked in one gear)
- Slipping or shuddering during gear changes
How to diagnose it
- Record freeze-frame data and transmission codes, then check live data for commanded solenoid B state and shift symptoms to see when the fault occurs.
- Check the transmission fluid condition and level using the manufacturer's procedure, since contaminated fluid or debris can restrict solenoid movement.
- Inspect the transmission case connector and wiring for damage, contamination, or poor contact that could affect solenoid B.
- Use a scan tool's supported active test to command solenoid B and compare the response with the manufacturer's expected operation.
- If the electrical command is correct but solenoid B remains on, inspect the solenoid and valve body for sticking, debris, or wear.
Common fixes
- Correct the fluid level if it is wrong, and service contaminated fluid as specified by the manufacturer.
- Clean and repair a contaminated or poorly seated transmission connector.
- Repair damaged wiring to shift solenoid B.
- Clean or replace a sticking shift solenoid B.
- Repair or replace a worn or sticking valve body component.
Can I keep driving?
Avoid towing, hard acceleration, and long trips while shifts are harsh, delayed, slipping, or unpredictable. Continued driving can worsen transmission wear; stop if it loses drive or slips severely.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.