U0093Vehicle Communication Bus H Performance
- Generic OBD-II code · Network
- How the car detects it
- U0093 says Vehicle Communication Bus H works, but with too many errors or too much delay. U0093 appears in no public manufacturer document. Unlike the wire codes U0094 to U009A, nothing is open or shorted; the signals are merely unreliable. A frequent background is a ground offset between modules. Texas Instruments describes the potential difference between the grounds of sender and receiver as common-mode voltage, with ISO 11898 requiring tolerance from -2 to +7 V, and lists erratic resets, lock-ups and corrupted data as results when it is exceeded. In a car this happens with loose or corroded ground points. On a CAN, each corrupted frame triggers an error frame and a repeat, which costs bandwidth long before any node is shut off.
- What you may notice
- Functions on Bus H drop out briefly and recover
- Modules restart or freeze sporadically
- Likely causes
- LikelyLoose or corroded ground point of a Bus H module
- PossibleLoose terminal causing short interruptions
- RareInterference coupled in from nearby loads or retrofitted devices
- Repair
- Hard · Usually a job for a workshop.Typical cost: €50 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.