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U042500 — Auxiliary heater control unit – signal implausible
Auxiliary heater control unit – signal implausible. 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 U042500
How to read and clear U042500
- 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 U042500 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 Air Conditioning
| U040100 | Engine electronics (DME) control unit – signal implausible |
| U040200 | Transmission control unit, signal implausible |
| U041300 | High-voltage battery control unit, signal implausible |
| U041600 | Data bus - fault value received |
| U042200 | Front-end electronics control unit (BCM1) - signal implausible |
| U042300 | Instrument cluster control unit – signal implausible |
| U045200 | Airbag control unit - signal implausible |
| U045600 | Thermal management control unit - signal implausible |
| U101100 | Supply voltage – too low |
| U101200 | Supply voltage – too high |
| U101300 | Coding |
| U103000 | LIN bus 1 – electrical fault |
All 418 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.