U353EHigh Voltage System Interlock Circuit N Performance
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U353E marks loop N as implausible. Such a verdict can stem from electrical interference rather than from the loop wiring. Tesla bulletin SB-25-17-005 for 2023 and 2024 Model Y cars describes the centre high mounted stop lamp disturbing the supply line of the high-voltage controller, which set HVIL alerts on an intact loop; the fix is a ferrite clipped around the thickest tan wire of that harness branch. A fault that coincides with braking or with other loads switching on suggests similar coupling on loop N. No maker documents U353E. Wiring checks then find nothing, and the warning may clear by itself.
- What you may notice
- High-voltage warning that appears briefly, sometimes when braking
- No fault found on loop resistance checks
- Occasional refusal to become ready
- Likely causes
- PossibleInterference from another load coupling into the supply of the monitoring controller
- PossibleLoose contact in a loop N connector
- RareFerrite or shielding missing after harness repair
- RareEvaluation software of the controller too sensitive
- Repair
- Hard · Usually a job for a workshop.Typical cost: €50 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.