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B121400 — Seat occupancy detection control unit - function restriction, environmental influences

Seat occupancy detection control unit - function restriction, environmental influences. 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 B121400

Porsche Taycan

Porsche 911 (992)

Porsche Panamera (971, 2017–2023)

Porsche Panamera (972, 2024–)

Porsche Cayenne (9YA)

How to read and clear B121400

  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 B121400 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 →

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Other codes of the Airbag

B120F00Passenger airbag ignition circuit discharge valve - equipment fault
B120F01Passenger airbag ignition circuit discharge valve - electrical fault
B120F11Passenger airbag ignition circuit discharge valve - short circuit to ground
B120F12Passenger airbag ignition circuit discharge valve - short circuit to B+
B120F1APassenger airbag ignition circuit discharge valve - resistance too low
B120F1BPassenger airbag ignition circuit discharge valve - resistance too high
B122501Seat occupancy detection control unit, sensor – electrical fault
B122511Seat occupancy detection control unit, sensor – short circuit to ground
B122512Seat occupancy detection control unit, sensor – short circuit to B+
B12251ASeat occupancy detection control unit, sensor – resistance too low
B12251BSeat occupancy detection control unit, sensor – resistance too high
B1225F0Seat occupancy detection control unit, sensor - open circuit diagnosis not possible

All 723 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.