U350AControl Module Input Power C Circuit High
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- U350A is the overvoltage code for supply C. GM's electric brake booster (2016–2019 hybrid tables) logs it when voltage sensor 2 on the motor driver supply exceeds 19.8 V for 90 s at speeds above 4 mph, Type A, so a single failing trip lights the MIL. The limit is higher than the 16 to 18 V thresholds used for feeds A and B because the motor stage tolerates more, yet a lasting excess is treated as serious since it threatens the power transistors. The pass condition is a straight drive over 3.1 miles or more. Such values rarely arise in a healthy 12 V system: think of a failed generator regulator or DC/DC converter, jump-starting from a 24 V source, or, with normal battery voltage, an internal sensing error.
- What you may notice
- MIL and brake warning on the first trip
- Brake assist reduced or switched off
- Likely causes
- PossibleGenerator regulator or DC/DC converter overcharging
- PossibleJump start from a 24 V source
- PossibleFaulty measurement of feed C inside the module
- Repair
- Medium · Usually a job for a workshop.Typical cost: €20 – €1,200
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.