U350C code meaning
Control Module Cooling Fan Circuit/Open
What U350C means
U350C reports that the fan built into or attached to a control module draws no current, or its circuit is open, at the moment the module switches it on. Some electronics carry their own blower: on the 2021 Toyota RAV4 Prime the plug-in charger has a fan with a speed sensor (bulletin T-SB-0021-21, code P1CE931), and the central infotainment unit of the Karma Revero has one under a shroud (TB-24-94-01). For electrical parts that cool inverters and traction batteries, CARB requires circuit and function monitoring. No maker documents U350C itself. With the fan dead, the module heats up and may cut its own output, charge more slowly or shut down. Shorts are split off into U350D/U350E; U350F covers a fan that is wired correctly but runs wrong.
U350C at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modePossible
- Repair difficultyMedium
- Typical labor0.5 to 3 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U350C
- Module fan silent when it should run
- Module overheats, reduces output, charges slower or restarts
- Temperature warning or function message for the affected module
Common causes of U350C
- Most likelyFan motor winding or brushes open
- PossibleFan plug loose or not latched after the module was removed
- PossibleBroken fan supply or control wire
- Less likelyFan output stage inside the module failed open
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Module cooling fanFan wiring
What each part of U350C means
| U | Network system: communication between the control modules (CAN bus). |
| 3 | Reserved range, usually generic. |
| 0C | The exact fault in that area. |
What to do next
- Note U350C 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 U350C
What does U350C mean?
U350C means "Control Module Cooling Fan Circuit/Open". U350C reports that the fan built into or attached to a control module draws no current, or its circuit is open, at the moment the module switches it on. It is a generic code, so it means the same on every make.
Is it safe to drive with U350C?
Drive gently and only to a workshop. With U350C the car can go into limp mode (reduced power) to protect itself.
Will U350C fail an emissions test?
U350C 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 U350C to fix?
Difficulty: medium. A typical repair takes 0.5 to 3 hours of work. This is a job for a workshop.
Will U350C clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.