U0053Vehicle Communication Bus C (-) High
- Generic OBD-II code · Network
- Can trigger limp mode
- How the car detects it
- U0053 reports too much voltage on the (-) conductor of Vehicle Communication Bus C, meaning CAN-Low if Bus C is built as a high-speed CAN, and NXP's TJA1041 application note states that a short of CAN-Low either to battery or to the 5 V transceiver supply makes communication impossible, while onsemi's measurements show the transmitting node stuck in endless failed attempts. All Bus C members go quiet together. A fault-tolerant low-speed bus separates the two cases: the TJA1055 data sheet treats CAN-Low at 5 V as a failure it simply tolerates, but at battery voltage it switches off its CAN-Low driver after a delay and receives over CAN-High alone. No manufacturer documents U0053 publicly. With the ignition on, CAN-Low near 5 V or battery voltage against ground confirms the fault.
- What you may notice
- All functions on Bus C drop out at once (high-speed type)
- Lost-communication codes in modules on other networks
- Warning lamps or fallback modes depending on the affected modules
- Likely causes
- Likely(-) wire of Bus C touching a battery or 5 V feed
- PossibleMoisture in a connector bridging the (-) wire to a supply pin
- RareDamaged transceiver holding CAN-Low high
- 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.