U0047
Vehicle Communication Bus C Performance
Communication network (CAN bus)
Generic OBD-II
Medium
What it means
U0047 means communication on bus C is present but out of spec — messages are dropping, delayed, or corrupted rather than fully absent. "Performance" codes usually point to an intermittent problem such as a loose connector or a wire that only faults when hot or vibrated, which is why features flicker in and out. Finding the unstable connection is the main challenge.
Medium
Can I keep driving? Often drivable, but the intermittent nature means features can drop out unpredictably — confirm no critical module is affected.
Common symptoms
What you'll notice
- Warning lights that come and go
- Modules on bus C responding intermittently when scanned
- Features flickering, resetting, or dropping out at random
- Other U-series codes stored together with this one
Common causes
Most likely first
- Intermittent open or high resistance in the bus C wiringLikely
- Loose, corroded, or backed-out connector pinsCommon
- A connector that only faults when hot, wet, or vibratedCommon
- A module intermittently disrupting bus timingLess often
- Poor ground or damaged terminal on the networkLess often
How to diagnose & fix
Work through it in order
- Scan all modules and note which ones on bus C respond inconsistently.
- Wiggle-test the bus C harness and connectors while watching live data for dropouts.
- Check for corroded or loose pins and clean/re-seat connectors.
- Inspect grounds and terminals along the bus for high resistance.
- Repair the intermittent fault, clear the code, and drive-cycle to confirm it stays gone.
FAQ
Quick answers
Is it safe to drive with U0047?+
Usually, if only body/comfort modules are affected, but intermittent bus faults are unpredictable. Have it diagnosed rather than relying on it.
Can I just clear U0047?+
It may stay off briefly, but a 'performance' code means an intermittent fault that will return until the loose or corroded connection is found.
Related codes
Often seen with U0047
Read & clear U0047 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX