Pohjannaula Pohjannaula
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Pohjannaula

Read-only diagnostics for Polestar 2 & Volvo CMA

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Read battery health, vehicle info, and trouble codes straight from your car — entirely on your device. No account, no servers, nothing sent to the cloud.

Battery
State of health, charge, pack voltage, cell voltages, temperatures, 12V system.
Vehicle
VIN, odometer, service intervals, key position, uptime.
Trouble codes
Scan every ECU and read fault codes with descriptions.
Live data
Poll drivetrain, battery, and thermal sensors in real time.
Tools
ECU presence map and a Data Identifier sweep.
Demo mode
Explore the whole app with sample data — no car needed.

⚠️ Required hardware

Pohjannaula talks to the car over wired Ethernet, not Bluetooth or Wi‑Fi. You need two things — the app cannot connect to a car without both:

  1. An OBD‑II ENET / VOE cable — a passive cable with the car's OBD‑II plug on one end and an Ethernet (RJ45) jack on the other. ENET is the BMW name; VOE is the Volvo/Polestar equivalent.
  2. A USB‑C–to–Ethernet adapter to plug that RJ45 into your phone or tablet.

For the USB‑C Ethernet adapter, pick a well-supported chipset: Realtek RTL8156B / RTL8153 works the most broadly (phones and tablets, iOS and Android — recommended). ASIX AX88179 / AX88179B also works on many devices, but support varies. See Support for full setup.

The app is strictly read-only — it cannot change any vehicle setting. No adapter handy? Open the app and type demo to explore everything with sample data.

Pohjannaula is an independent tool and is not affiliated with, endorsed by, or sponsored by Polestar or Volvo. "Polestar" and "Volvo" are trademarks of their respective owners; they are used only to describe vehicle compatibility.