U3542High Voltage System Interlock Circuit O Performance
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U3542 marks loop O as implausible. Interlock trouble often clusters around charging. Mercedes bulletin LI54.10-P-067823 for the third-generation smart electric drive with the optional 22 kW on-board charger, built before 25 March 2013, links sporadic or permanent interlock codes (P0A0A00, P0A0E00), a no-start with a charging-cable message and a battery that will not charge to loose low-voltage contacts at that charger. Technicians push or pull those plugs gently and wait up to 5 seconds each time to see whether charging begins; the fault may appear solely with cold or warm components. No maker documents U3542.
- What you may notice
- Vehicle will not start and reports a plugged-in charging cable
- Charging does not start or stops
- Fault at the beginning or end of a charging session
- Likely causes
- LikelyLoose low-voltage contact at the on-board charger carrying loop O
- PossibleContact that opens only when components are hot or cold
- RareInternal fault in the on-board charger
- Repair
- Hard · Usually a job for a workshop.Typical cost: €50 – €2,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.