U0011Medium Speed CAN Communication Bus Performance
- Generic OBD-II code · Network
- How the car detects it
- U0011 says the medium-speed CAN is running but not dependably: expected periodic messages come late or not at all, error frames accumulate, or a node briefly goes bus-off and rejoins. No manufacturer publicly documents U0011 in its J2012 sense with thresholds. The nearest model is GM's high-speed counterpart U0002, where a supervised message missing for more than 250 ms sets the code. Alfa Romeo even assigns the number to something else: in the Giulia and Stelvio drive style control module, U0011-14 and U0011-15 mark a faulty down circuit of the DNA rotary selector. Typical causes are loose or corroded connectors, water ingress, voltage dips during cranking and module software. Body and comfort functions then work only intermittently while the car itself drives normally.
- What you may notice
- Comfort functions such as windows, locks or climate controls work intermittently
- Code stored as history in body modules
- Likely causes
- LikelyLoose or corroded connector on the medium-speed pair
- PossibleLow battery voltage or poor ground causing module resets
- PossibleModule software miscounting or missing messages (update needed)
- Repair
- Medium · Usually a job for a workshop.Typical cost: €50 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.