U3533High Voltage System Interlock Circuit K Low
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U3533 says loop K reads too low. Apart from an open plug, part of the loop current may be escaping somewhere. Tesla's HVIL tech note for the Model S describes two such cases: a drive inverter whose control board leaked some of the nominal 20 mA loop current to ground, and a loop wire squeezed against ground close to a seat belt pretensioner. The fault therefore need not sit in a connector at all; a component on the loop or a wire trapped by seat or trim parts can cause it. When every plug of loop K is latched and the value stays low, measure the loop current at each component and inspect wiring near seat mounts. No maker documents U3533; the contactors remain open.
- What you may notice
- Vehicle does not reach ready mode
- Fault may follow work on seats or interior trim
- Warning to have the high-voltage system checked
- Likely causes
- LikelyLoop K wire squeezed against ground by seat, trim or mounting parts
- PossiblePlug within loop K not connected
- RareHigh-voltage component on loop K leaking loop current to ground internally
- Repair
- Hard · Usually a job for a workshop.Typical cost: €80 – €2,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.