U3507Control Module Input Power B Circuit Intermittent/Erratic
- Generic OBD-II code · Network
- Can trigger limp mode
- How the car detects it
- U3507 covers an unsteady supply B: the voltage is mostly in range but drops out or jumps for short moments. Since B often powers stages such as motors or valves, the dropouts typically appear when these draw current, for instance while braking or steering. GM's brake booster tables show that the module judges B over short and long windows (0.2 s up to 90 s); a fault that merely flickers fits neither the low nor the high code and counts as erratic. No manufacturer documents U3507 publicly. Suspect loose crimp contacts, worn fuse holders, corroded grounds and chafed wires, and test under load with a recording meter or scope. If U3505 or U3018 are stored as well, the feed has probably dropped out completely at times.
- What you may notice
- Brief function dropouts when power stages switch on
- Code returns sporadically and is hard to reproduce
- Likely causes
- LikelyLoose crimp or worn fuse holder in feed B
- PossibleCorroded ground point of the module
- PossibleChafed wire with intermittent contact
- Repair
- Medium · Often possible to do yourself.Typical cost: €10 – €500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.