U0050 code meaning
Vehicle Communication Bus C (+) High
What U0050 means
U0050 flags excess voltage on the (+) wire of Vehicle Communication Bus C. On a high-speed-style CAN bus, the conductor is CAN-High sitting at battery or 5 V level, a condition onsemi found survivable: frames still pass, the dominant bits merely look different and the transceiver draws about as little as when idle, since its high-side driver delivers no current. NXP therefore lists it with the hidden failures that need transceiver diagnosis to surface at all. Fault-tolerant low-speed transceivers such as NXP's TJA1055 confirm the fault in two timed steps and then fall back to single-wire operation on CAN-Low. Because driving rarely changes, the code is often found by chance during a scan. No manufacturer documents U0050 publicly. CAN-High near supply voltage against ground confirms it.
U0050 at a glance
- Check engine lightUsually not
- Emissions testNot an emissions code
- Limp modeNot expected
- Repair difficultyHard
- Typical labor1 to 5 hours
- Clears after repairWhen cleared with a scanner
Symptoms of U0050
- Usually no symptom, code found during a scan
- Occasional single warning from a module on Bus C
Common causes of U0050
- Most likely(+) wire of Bus C touching a battery or 5 V feed
- PossibleMoisture in a connector linking the bus wire to supply
- Less likelyAftermarket device tapped into the bus wire
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
Bus c wiringCAN transceiver
What each part of U0050 means
| U | Network system: communication between the control modules (CAN bus). |
| 0 | Generic code: it means the same on every make (SAE standard). |
| 50 | The exact fault in that area. |
What to do next
- Note U0050 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 U0050
What does U0050 mean?
U0050 means "Vehicle Communication Bus C (+) High". U0050 flags excess voltage on the (+) wire of Vehicle Communication Bus C. It is a generic code, so it means the same on every make.
Is it safe to drive with U0050?
U0050 does not normally turn on the check engine light by itself. Watch for the symptoms above and have it checked soon.
Will U0050 fail an emissions test?
U0050 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 U0050 to fix?
Difficulty: hard. A typical repair takes 1 to 5 hours of work. This is a job for a workshop.
Will U0050 clear itself after the repair?
Clear the code with a scanner after the repair. If the fault is fixed, it does not come back.