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B121811 — Right low beam headlamp bulb, Short circuit to ground
Right low beam headlamp bulb, 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 B121811
How to read and clear B121811
- Plug a standard ENET (Ethernet-to-OBD) cable into your Porsche's OBD port and your Mac or Windows PC.
- Open STEUER14, pick your car and run a fault scan: every control unit is read, and B121811 shows with its status, its full description and the freeze frame when the unit stores one.
- 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 readingOther codes of the Central Electrics
| B11EA11 | Right front turn signal bulb, Short circuit to ground |
| B11EA15 | Right front turn signal bulb, Open circuit/short circuit to B+ |
| B120012 | Interior light delay (dimmer), Short circuit to B+ |
| B120101 | Instrument panel and switch illumination dimmer switch, Electrical error |
| B121711 | Left low beam headlamp bulb, Short circuit to ground |
| B121715 | Left low beam headlamp bulb, Open circuit/short circuit to B+ |
| B121815 | Right low beam headlamp bulb, Open circuit/short circuit to B+ |
| B121911 | Left high beam headlamp bulb, Short circuit to ground |
| B121915 | Left high beam headlamp bulb, Open circuit/short circuit to B+ |
| B121A11 | Right high beam headlamp bulb, Short circuit to ground |
| B121A15 | Right high beam headlamp bulb, Open circuit/short circuit to B+ |
| B121B11 | Left low beam headlamp reflector motor, Short circuit to ground |
All 1472 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.