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B148421 — LIN bus 1 – not taught

LIN bus 1 – not taught. 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 B148421

Porsche Taycan

Thermal Management

Porsche 911 (992)

TME (Thermomanagement)

Porsche Panamera (971, 2017–2023)

TME (Thermomanagement)

Porsche Panamera (972, 2024–)

TME (Thermomanagement)

Porsche Cayenne (9YA)

TME (Thermomanagement)

How to read and clear B148421

  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 B148421 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 Thermal Management

B145317Electric A/C compressor – function restriction due to overvoltage
B14534BElectric A/C compressor – function restriction due to overtemperature protection
B1453F0Electric air-conditioning compressor (V470) - motor, high-voltage supply error
B1453F1Electric A/C compressor – power output fault
B1453F2Electric air-conditioning compressor (V470), temperature shutdown
B1453F3Electric air-conditioning compressor (V470) – overload protection active
B148422LIN bus 1 – not taught
B148521LIN bus 2 – not taught
B148522LIN bus 2 – not taught
B158011Refrigerant cut-off valve 2, Short circuit to ground
B158012Shut-off valve 2 for refrigerant, Short circuit to B+
B158013Shut-off valve 2 for refrigerant, Open circuit

All 636 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.