U3501Control Module Input Power A Circuit Low
- Generic OBD-II code · Network
- Can trigger limp mode
- How the car detects it
- U3501 reports that supply A of a module is below its permitted range. GM's electric brake booster (BSC2) in the 2016–2019 hybrid OBD tables runs two checks: the CAN/logic supply under 7.5 V for 0.09 s, and the internal sensor for the module supply under 4.9 V for 0.2 s, a level below the point where the hardware should already have shut down. Both are Special Type C, so no MIL. The weight of the code lies elsewhere: GM lists U3501 among the conditions that suspend many other booster tests, because motor and sensor checks are meaningless without proper supply. It passes after 30 s with ignition on. Usual causes are a weak or discharged battery, a deep dip while cranking, a corroded fuse or terminal on the feed, or a bad ground.
- What you may notice
- Module resets or drops off the network at low voltage
- Other self-tests of the module suspended
- Warning lamp for the affected system, usually without MIL
- Likely causes
- LikelyWeak or discharged 12 V battery
- PossibleDeep voltage dip during engine start
- PossibleCorroded fuse, terminal or ground in the A feed
- RareInternal supply stage of the module faulty
- Repair
- Easy · Often possible to do yourself.Typical cost: €10 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.