Home › Fault codes › U140800

U140800 — Internal voltage measurement, Implausible signal

Internal voltage measurement, Implausible signal. The Taycan, 911 (992), 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 U140800

Porsche Taycan

DC/DC Converter 2DC/DC ConverterSeat Module, DriverSeat Module, Passenger

Porsche 911 (992)

Seat Module, DriverSeat Module, Passenger

Porsche Panamera (971, 2017–2023)

Seat Module, DriverSeat Module, PassengerSeat Control Module, Rear Driver SideSeat Control Module, Rear Passenger Side

Porsche Panamera (972, 2024–)

Seat Module, DriverSeat Module, PassengerSeat Control Module, Rear Driver SideSeat Control Module, Rear Passenger Side

Porsche Cayenne (9YA)

Seat Module, DriverSeat Module, Passenger

How to read and clear U140800

  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 U140800 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 DC/DC Converter 2

U111600Subnetwork operation not available
U112100Data bus - missing message
U112200Data bus - implausible message
U112300Data bus – fault value received
U140000Function restriction – supply voltage too low
U140100Function restriction – supply voltage too high

All 34 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.