U3572 code meaning
Stack Outlet Coolant Temperature Sensor 2 Circuit
Network system Generic code U35xx codes Check engine light
What U3572 means
U3572 is logged when the second coolant temperature sensor at the stack outlet has a wiring or signal problem. No maker explains in public why two sensors share this spot; mutual checking is the obvious reason. A Toyota patent for systems with several stacks shows one way: outlet temperature is estimated from inlet temperature and stack output, and an outlet sensor whose reading departs from that estimate is reported as faulty. GM compares the outlet value with an expected figure to spot a failed coolant pump and may then lower stack output. Hyundai campaign 21-01-045H-1 for the Nexo shows that a stack coolant fault (pump code P1D3D94) lights the check engine lamp. No maker documents U3572 publicly. With sensor 1 still valid a warning may be all; with both lost, power will be cut. Sensor 1 is U3571.
U3572 at a glance
- Check engine lightYes, usually on
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyHard
- Typical labor0.5 to 2.5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U3572
- Fuel cell system warning, MIL on
- Little or no change in driving as long as sensor 1 is valid
- Reduced power if both outlet sensors are affected
Common causes of U3572
- Most likelyOpen, short or corrosion in wiring or connector of outlet sensor 2
- PossibleOutlet temperature sensor 2 faulty internally
- Less likelyShared sensor ground faulty (often with U3571 at the same time)
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Stack outlet coolant temp sensor 2Sensor wiring
What each part of U3572 means
| U | Network system: communication between the control modules (CAN bus). |
| 3 | Reserved range, usually generic. |
| 72 | The exact fault in that area. |
What to do next
- Note U3572 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 U3572
What does U3572 mean?
U3572 means "Stack Outlet Coolant Temperature Sensor 2 Circuit". U3572 is logged when the second coolant temperature sensor at the stack outlet has a wiring or signal problem. It is a generic code, so it means the same on every make.
Is it safe to drive with U3572?
Drive gently and only to a workshop. With U3572 the car can go into limp mode (reduced power) to protect itself.
Will U3572 fail an emissions test?
U3572 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 U3572 to fix?
Difficulty: hard. A typical repair takes 0.5 to 2.5 hours of work. This is a job for a workshop.
Will U3572 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.