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B12C311 — Outer right brake light – short circuit to ground

Outer right brake light – short circuit to ground. 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 B12C311

Porsche Taycan

Porsche 911 (992)

Porsche Panamera (971, 2017–2023)

Porsche Panamera (972, 2024–)

Porsche Cayenne (9YA)

How to read and clear B12C311

  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 B12C311 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 Comfort System Module

B12C113Right marker light in tailgate – open circuit
B12C115Right marker light in tailgate – short circuit to B+ or open circuit
B12C211Outer left brake light – short circuit to ground
B12C212Outer left brake light – short circuit to B+
B12C213Outer left brake light – open circuit
B12C215Outer left brake light – short circuit to B+ or open circuit
B12C312Outer right brake light – short circuit to B+
B12C313Outer right brake light – open circuit
B12C315Outer right brake light – short circuit to B+ or open circuit
B12C411Left brake light in tailgate – short circuit to ground
B12C412Left brake light in tailgate – short circuit to B+
B12C413Left brake light in tailgate – open circuit

All 616 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.