U3532High Voltage System Interlock Circuit K Performance
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U3532 indicates that loop K does not respond the way the controller expects. Some checks run only while the system powers up. A Ford patent describes one: during precharge a switch holds the high-voltage bus between an upper and a lower level far below operating voltage, and the interlock test takes place inside that window. Too little current then suggests a connector that is not seated, too much a short, and only a passed test lets precharge carry on. A start-only test of this kind can let a marginal contact pass on one key cycle and fail on the next, so the code may come and go between trips. No maker publishes U3532. Expect occasional refusals to become ready.
- What you may notice
- Vehicle sometimes does not become ready at switch-on, then works on the next attempt
- Fault stored at start-up rather than while driving
- Likely causes
- LikelyMarginal contact in a loop K connector that passes some start checks and fails others
- RareFault in the precharge path disturbing the start-up check
- RareController software with outdated check limits
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.