U352AHigh Voltage System Interlock Circuit H Performance
- Generic OBD-II code · Network
- Turns on the check-engine light
- Can trigger limp mode
- How the car detects it
- U352A says the eighth loop is closed but its electrical values leave the calibrated band. In CATL's interlock patent the decision thresholds follow from the loop current, a sensing resistor and the impedance of every HV part in the chain. A long loop through many parts therefore has narrow margins: each extra contact, a replacement part with different internal resistance or a lengthened harness shifts the result. That makes a performance fault on a late loop plausible after repairs or conversions. No maker publishes U352A. Compare part numbers of recently fitted HV parts with the originals and look for added plugs in loop H.
- What you may notice
- Fault appears after a repair or conversion
- High-voltage system switches off occasionally
- Likely causes
- PossibleReplacement HV component with different interlock resistance fitted
- PossibleExtra connector or harness extension added to loop H
- PossibleRising contact resistance at several loop H terminals
- Repair
- Workshop only · Usually a job for a workshop.Typical cost: €100 – €2,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.