Drivable short-term, but fix now to avoid damage.
This code means the transmission control module detected a problem with the 1-2 shift, the change between first and second gear. It's often caused by a faulty shift solenoid, low or dirty transmission fluid, or wear in the valve body or internal components. Typical fixes include servicing the fluid, replacing the shift solenoid, or repairing the valve body.
$150 – $1200
Varies by vehicle and root cause.
Keep driving to a minimum. Trouble shifting between first and second can cause slipping or limp mode, so get it diagnosed soon to avoid further transmission wear.
Repairs range from about $150 for a fluid service or solenoid to $1,200 or more if the valve body or internal components need work.
Yes, it's serious. Problems with the 1-2 shift affect everyday driving and can worsen, leading to costly repairs, so it's best addressed promptly.
The 1-2 shift happens every time you accelerate from a stop, so a fault here is very noticeable and puts repeated stress on the transmission if left unfixed.