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U140A00 — Terminal 30 supply voltage – open circuit

Terminal 30 supply voltage – open circuit. 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 U140A00

Porsche Taycan

Central ElectricsComfort System ModuleRear Axle SteeringSteering Assist

Porsche 911 (992)

BCM1 (Body Control Module 1)BCM2 (Body Control Module 2)Engine Control Module 1Steering Assist

Porsche Panamera (971, 2017–2023)

EBKV (Bremskraftverstaerker)BCM1 (Body Control Module 1)BCM2 (Body Control Module 2)Engine Control Module 1Rear Axle SteeringSteering Assist

Porsche Panamera (972, 2024–)

BCM1 (Body Control Module 1)BCM2 (Body Control Module 2)Engine Control Module 1Rear Axle SteeringSteering Assist

Porsche Cayenne (9YA)

EBKV (Bremskraftverstaerker)BCM1 (Body Control Module 1)BCM2 (Body Control Module 2)Engine Control Module 1Rear Axle SteeringSteering Assist

How to read and clear U140A00

  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 U140A00 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 Central Electrics

U13F500Right ambient light, rear cupholder in front center console (AL4) – message implausible
U13F600Left ambient light, rear cupholder, front center console (AL5) – no communication
U13F700Left ambient light, rear cupholder, front center console (AL5) – message implausible
U140000Function restriction – supply voltage too low
U140100Function restriction – supply voltage too high
U140500Terminal 15 signal line – signal implausible
U141200Terminal 30-2 supply voltage – open circuit
U141300Terminal 30-3 supply voltage – open circuit
U141400Terminal 30-4 power supply – open circuit
U141500Terminal 30-5 power supply – open circuit
U141600Terminal 30-6 power supply – open circuit
U150000LIN bus 5 - electrical fault

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.