U352C code meaning
High Voltage System Interlock Circuit H High
Network system Generic code U35xx codes Check engine light
What U352C means
U352C reports an excessive reading on loop H. Whether that points to foreign voltage or to a break depends on the quantity the controller evaluates. If it reads voltage, a wire touching 12 V is the usual reason. If it works out the loop's resistance, as Lear's tester patent does, a value beyond the maximum is treated as open and one under the minimum as shorted, so high may mean corrosion or a loose terminal. The service data of the specific vehicle settles which reading applies; for U352C no maker publishes it. Measure loop H resistance with every plug latched and compare it with a sound loop of the same vehicle.
U352C at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 4 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U352C
- No ready mode, high-voltage warning
- Fault sometimes disappears after moving connectors
Common causes of U352C
- PossibleLoop H wire in contact with a 12 V supply
- PossibleCorroded or loose terminal raising loop H resistance
- Less likelyLoop source stuck on in the controller
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Hvil loop hHvil wiring
What each part of U352C means
| U | Network system: communication between the control modules (CAN bus). |
| 3 | Reserved range, usually generic. |
| 2C | The exact fault in that area. |
What to do next
- Note U352C and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about U352C
What does U352C mean?
U352C means "High Voltage System Interlock Circuit H High". U352C reports an excessive reading on loop H. It is a generic code, so it means the same on every make.
Is it safe to drive with U352C?
Drive gently and only to a workshop. With U352C the car can go into limp mode (reduced power) to protect itself.
Will U352C fail an emissions test?
U352C is not an emissions code, so on its own it usually does not fail an emissions test. Other stored codes or a lit check engine light still can.
How hard is U352C to fix?
Difficulty: hard. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will U352C clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.