U0068Vehicle Communication Bus E (+) High
- Generic OBD-II code · Network
- How the car detects it
- U0068 flags the (+) wire of Vehicle Communication Bus E at an excessive voltage, from battery or a 5 V rail. If Bus E is a high-speed CAN, the line in question is CAN-High, and traffic continues: onsemi saw frames pass with altered dominant levels, NXP files the case under hidden failures. Detecting it therefore depends on the module. NXP's TJA1041 note explains that a diagnosing transceiver must itself send at least four sufficiently long dominant phases before its failure flag is valid, and recommends reading the flag once a frame has finished, because arbitration with other senders can distort the measurement. That is why only some modules on Bus E, or none, may store the code. No manufacturer documents U0068 publicly. A meter on CAN-High showing roughly supply voltage to ground proves it.
- What you may notice
- Usually no symptom, code found by chance
- Code stored in only one module on Bus E
- Likely causes
- Likely(+) wire of Bus E chafed against a battery or 5 V feed
- PossibleMoisture in a connector bridging the bus wire to supply
- RareAftermarket device connected to 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.