U0059Vehicle Communication Bus D (+) High
- Generic OBD-II code · Network
- How the car detects it
- U0059 means the (+) line of Vehicle Communication Bus D sits at too high a voltage, typically from contact with a battery or 5 V feed. On a high-speed CAN layout the line concerned is CAN-High, and the fault belongs to the shorts NXP calls hidden: communication goes on, and only a transceiver with bus diagnosis can report it. NXP's TJA1041 note mentions a further side effect, namely that the bus wake-up logic of that device was designed so that a CAN-High short to battery does not wake the network while it goes to sleep; a hint that such a short can otherwise interfere with the network going to sleep. Fault-tolerant low-speed hardware like the TJA1055 handles it in two timed steps and ends on CAN-Low alone. No manufacturer documents U0059 publicly. Measured against ground, CAN-High sitting near supply voltage settles the diagnosis.
- What you may notice
- Usually no symptom, code found during a scan
- Occasional single warning from a module on Bus D
- Likely causes
- Likely(+) wire of Bus D touching a battery or 5 V feed
- PossibleMoisture in a connector bridging the bus wire to supply
- RareAftermarket device tapped into the bus wire
- 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.