Drive with caution — fix soon.
This code means the transmission control module detected an abnormally high voltage in the torque converter or brake switch "B" circuit, which it relies on to know when to engage or release the torque converter lockup. It's commonly caused by a faulty brake light switch, a problem in the torque converter clutch solenoid circuit, or damaged wiring and connectors. Repairs usually involve testing the switch and circuit and replacing the faulty part, which is often a manageable fix.
$100 – $400
Varies by vehicle and root cause.
Usually yes, at least for a while, but you may notice the torque converter not locking up and slightly worse mileage. It's best to get it diagnosed soon.
Repairs commonly range from $100 to $400. A brake light switch is inexpensive, but a torque converter solenoid or wiring repair can cost more.
It's moderately serious. It mainly affects torque converter lockup and efficiency rather than safety, but it's worth fixing to keep the transmission running smoothly.
Yes. This circuit often ties into the brake switch, so a faulty or misadjusted brake light switch is a common cause of a high-voltage reading here.