U0048Vehicle Communication Bus C (+) Open
- Generic OBD-II code · Network
- How the car detects it
- U0048 stands for an open (+) wire on Vehicle Communication Bus C, CAN-High where Bus C is a CAN. Deutz places the code on CAN 4 of its EMR L1 engine controller, listed for main and secondary ECU as an open circuit on that channel, just as U0039 covers CAN 3. Electrically, an interrupted CAN-High wire splits a high-speed CAN into islands that keep working internally; NXP points out that transceiver diagnosis cannot report such a break, so the controller relies on missing messages. A fault-tolerant low-speed transceiver such as NXP's TJA1055 rides through the same break with its drivers left active. Expect lost-communication entries for nodes located past the interruption. No car maker documents U0048 publicly. Check connector seating, crimp terminals and harness flex points first.
- What you may notice
- Modules on the far side of the break unreachable
- Lost-communication codes in several modules
- Likely causes
- Likely(+) wire of Bus C broken at a flex point or splice
- PossibleLoose crimp or backed-out terminal
- PossibleConnector not fully seated
- Repair
- Hard · Usually a job for a workshop.Typical cost: €60 – €700
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.