U3502Control Module Input Power A Circuit High
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U3502 means supply A rises above its allowed limit. In GM's 2016–2019 hybrid OBD tables the electric brake booster checks its CAN supply voltage and sets U3502 above 16 V lasting 0.09 s while its software runs; this is Type B, so the MIL comes on after two failing trips, and the test passes after 30 s with ignition on. Unlike low voltage, which a module can often ride out, overvoltage endangers electronics and power stages, which explains the short reaction time. Common causes are a regulator fault in the generator or DC/DC converter, jump-starting from a 24 V source or a wrongly set charger, and a load dump when a battery cable comes loose while charging. If several modules report high voltage at the same moment, the charging system is at fault, not the module.
- What you may notice
- MIL after repeated trips
- Several modules logging overvoltage at once
- Flickering lights or battery warning
- Likely causes
- LikelyGenerator regulator or DC/DC converter overcharging
- PossibleJump start or external charger with excessive voltage
- PossibleLoose battery terminal causing voltage spikes
- RareFaulty voltage measurement inside the module
- Repair
- Medium · Often possible to do yourself.Typical cost: €20 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.