Vehicle Communication Bus C (+) High
What it means
U0050 means the voltage on the positive wire of vehicle communication bus C is higher than expected — usually a short to power or a wiring fault on the data network. Modules on bus C can't communicate normally, so features fail and warning lights come on. The severity depends on which systems use bus C: a body network just loses features, while a powertrain network can cause stalling or a no-start. It is almost always a wiring or connector issue.
Can I keep driving? Depends on the network — a high signal on bus C can mean anything from a few dead features to a no-start if it carries the powertrain, so diagnose before relying on the car.
Common symptoms
What you'll notice
- Multiple warning lights on at the same time
- Modules on bus C missing or responding erratically to a scan tool
- Features tied to bus C stop working
- Possible hard start or stalling if bus C serves the engine or transmission
Common causes
Most likely first
- Bus C positive circuit shorted to voltage, pulling the signal highLikely
- Chafed wiring touching a power feedCommon
- Corroded connector creating a false high readingCommon
- A failing module driving the bus highLess often
- Damaged splice or terminal from a prior repairLess often
How to diagnose & fix
Work through it in order
- Check which modules on bus C have dropped off to narrow the affected segment.
- Inspect the bus C positive wiring for a short to power, especially where the harness runs alongside battery or ignition feeds.
- Measure the (+) circuit voltage against spec to confirm the high condition.
- Disconnect suspect modules one at a time to see if the bus voltage returns to normal.
- Repair the shorted wiring or replace the faulty module, then clear and re-test.
FAQ
Quick answers
Is it safe to drive with U0050?+
Can I just clear U0050?+
Related codes
Often seen with U0050
Read & clear U0050 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.