U3548High Voltage System Interlock Circuit P High
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U3548 is the high-side code of loop P. When each unit adds a known share of loop resistance, a single suspect can be isolated by substitution. Tesla's Model S HVIL guide has technicians, after consulting a field engineer, place a 60-ohm resistor across the drive inverter's interlock pins at connector X250 and also bridge its CAN lines; if the contactors then close, the inverter's internal section is to blame. Such a stand-in serves only as a short test by trained staff and must be removed afterwards. No maker documents U3548. A raised reading calls for measuring the share of each component on loop P.
- What you may notice
- Contactors stay open, no ready mode
- High-voltage system warning
- Charging blocked
- Likely causes
- PossibleInternal interlock section of an HV component too resistive
- PossibleLoop P wire shorted to a 12 V feed
- PossibleLoose or poorly crimped interlock terminal in loop P
- Repair
- Hard · Usually a job for a workshop.Typical cost: €60 – €3,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.