U0098Vehicle Communication Bus H (-) Low
- Generic OBD-II code · Network
- How the car detects it
- U0098 is stored once the Bus H (-) wire, CAN-Low on a CAN, sits too low, normally from a short to ground. No manufacturer has made a use of U0098 public. With fault-tolerant low-speed CAN the short unfolds in stages: the receive pin of NXP's TJA1055 initially stays dominant without pause; once a time-out has passed, the chip disables its CANL driver and goes on receiving single-wire over CANH. Once the short is removed, normal levels return and the chip goes back to differential mode. Communication thus survives, but with less noise margin. A high-speed CAN also keeps running in this state, as onsemi measured, though with distorted levels. A resistance check of that wire against chassis, battery disconnected, confirms it.
- What you may notice
- Usually no noticeable symptom
- Occasional errors on Bus H in electrically noisy conditions
- Likely causes
- Likely(-) wire chafed to ground
- PossibleHarness pinched by a fastener or panel
- RareFaulty transceiver pulling the (-) line to ground
- Repair
- Hard · Usually a job for a workshop.Typical cost: €60 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.