Home › Fault codes › U104B00

U104B00 — Local data bus, Implausible signal

Local data bus, Implausible signal. The Taycan, Panamera (971), Panamera (972) and Cayenne report this code; below is which control unit sets it on each model and how to read and clear it.

Which models and control units set U104B00

Porsche Taycan

Porsche Panamera (971, 2017–2023)

Porsche Panamera (972, 2024–)

Porsche Cayenne (9YA)

How to read and clear U104B00

  1. Plug a standard ENET (Ethernet-to-OBD) cable into your Porsche's OBD port and your Mac or Windows PC.
  2. Open STEUER14, pick your car and run a fault scan: every control unit is read, and U104B00 shows with its status, its full description and the freeze frame when the unit stores one.
  3. Fix the cause first, then clear the fault memory and scan again to check it stays away. Reading and clearing fault codes is free on every control unit.

More about fault memory in the manual →

Download STEUER14 — free fault reading

Other codes of the Rear Axle Steering

U101100Supply voltage – too low
U101200Supply voltage – too high
U101300Coding
U101400Coding
U103000LIN bus 1 – electrical fault
U103100FlexRay data bus, No synchronization
U106E00FlexRay data bus - signal error
U10BA00LIN bus 1 – no communication
U110300Production mode active
U110500Transport mode active
U111200Data bus - implausible message
U112100Data bus - missing message

All 65 codes of this control unit →

Fault names come from the manufacturer's diagnostic data. STEUER14 is independent and not affiliated with Porsche AG. A code tells you what a control unit detected, not always which part failed — check wiring, supply voltage and related codes before replacing parts. STEUER14 shows each fault's full description, status and freeze frame on the car.