U3508Control Module Input Power C Circuit Range/Performance
- Generic OBD-II code · Network
- Can trigger limp mode
- How the car detects it
- U3508 checks the plausibility of a third supply input, C. Only modules with large or separately protected loads have three feeds; in GM's electric brake booster (2016–2019 hybrid tables) C is the motor driver feed, measured by voltage sensor 2 and compared with feed B through U3019 (ratio outside 0.766 to 1.321). U3508 would apply if C is present but its value does not suit the operating state, for instance staying high while the motor draws current or departing from battery voltage, without crossing a hard limit. No manufacturer documents U3508 publicly; GM uses only the Low and High codes for C. Check the motor feed and its ground under load and look for related U3019 or U3013.
- What you may notice
- Reduced function of the motor-driven system
- Correlation codes between feeds stored as well
- Likely causes
- PossibleResistance in the motor supply path of feed C
- PossiblePoor ground of the power stage
- RareDrift of the internal voltage divider
- Repair
- Medium · Often possible to do yourself.Typical cost: €10 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.