# Custom OBD2 PIDs on iPhone and CarPlay > Add manufacturer-specific OBD2 readings to Odo: choose from more than 13,800 presets for 105 electric and hybrid models, or enter your own mode, PID, header and formula, test it without an adapter, and see it live on iPhone and CarPlay. App: Odo: Speedometer, Drive & Ride (iPhone, iPad, Mac with Apple silicon, Apple CarPlay, Apple Watch). Free to download: https://apps.apple.com/app/id6759611784 Page: https://speedometerproapp.com/features/obd2-custom-pids Last updated: 2026-11-09 Standard OBD2 covers the basics. Custom PIDs let Odo read extra data your car’s manufacturer provides, such as battery cell data on an electric car, when you know the request. ## Why it matters Every manufacturer has readings beyond the standard set, and enthusiasts publish the requests to get them. Custom PIDs turn those into live readings, without a separate app for each car. ## Start from a preset Add from Presets opens a catalog built from the open OBDb database: more than 13,800 readings for 105 electric and hybrid models from 31 makes. Cars from your garage are listed first. - Search by make or model, then pick the model year - Battery, charging, cells, modules, motor and inverter, and energy readings - A seal marks formulas checked against recorded data from a real vehicle - Add one reading, or a whole category at once ## Or write your own Enter the request and the formula yourself. The editor takes the same details that PID lists and enthusiast forums publish. - Name, unit, mode, PID, header and receive address - Formulas with arithmetic, signed values and single bits - Test with sample bytes before you save, no adapter needed - An optional plausibility range, for all vehicles or just one ## See it live Custom readings appear in their own section of the OBD Live tab, and on CarPlay under Custom PIDs. Tap Read on any saved reading to fetch it on demand. - A Custom section in the Live tab on iPhone - Custom PIDs on the CarPlay OBD tab - Cell voltage readings grouped into cards - Set up any time, test once you’re connected ## How to set it up 1. **Open Custom PIDs**: Go to Garage → OBD II and tap Custom PIDs. 2. **Add a reading**: Tap New Custom PID to enter your own, or Add from Presets to pick from the catalog. 3. **Connect and read**: With the adapter connected, your readings appear live in the Custom section. Note: Custom readings are shown live and aren’t saved with trips, except an electric car’s state of charge, which Odo records at the start and end of each trip. Preset data comes from OBDb, licensed CC BY-SA 4.0. ## Questions and answers ### What is an OBD2 PID? A PID (parameter ID) is the code an app sends to ask the car's computer for one reading, such as RPM or coolant temperature. Standard PIDs are shared by all OBD2 cars, while manufacturers add their own for extra data like battery cell voltages, which Odo can read as custom PIDs. ### Where can I find custom PIDs for my car? Start with Add from Presets in Garage → OBD II → Custom PIDs, a catalog of more than 13,800 readings for 105 electric and hybrid models built from the open OBDb database. For other cars, enter the mode, PID, header and formula that PID lists and enthusiast forums publish. ### Can I test a custom PID without being connected to the car? Yes. The editor lets you test the formula with sample bytes before you save, with no adapter needed, and once you're connected you can tap Read on any saved reading to fetch it live. ### What happens if I add a preset for the wrong car? It simply reads no data. Presets only work on the vehicles they were made for, so add the ones that match your car's make, model and year. ### Does Odo work with electric cars over OBD2? Yes. Standard OBD2 data on electric cars is limited, so Odo includes a catalog of manufacturer-specific battery readings for 105 electric and hybrid models from 31 makes, built from the open OBDb database. Go to Garage → OBD II → Custom PIDs → Add from Presets, find your make, model and year, and add the readings you want: state of charge, state of health, pack voltage and current, cell voltages and temperatures and more, depending on the car. With a state of charge reading added, every trip also records the battery level at the start and end. Tesla doesn't provide standard OBD2 data. More at /features/ev-obd2. ### Which OBD2 adapters work with Odo? Odo works with ELM327-compatible OBD2 adapters that connect over Bluetooth Low Energy (BLE 4.0 or newer) or Wi-Fi. Adapters differ in quality and in how fully they implement the ELM327 command set, so results can vary: very cheap clones may drop the connection, read the VIN only partly, or miss some data. An adapter from an established seller is the safest choice, and if you already own one, try it first. Adapters that only work with their maker's own app, and classic Bluetooth adapters made for Android, won't connect. Setup steps and troubleshooting tips are in the app under Garage → OBD II → About & Compatibility, and on our compatibility page at /features/obd2-compatibility. ## Related - [EV and hybrid OBD2](https://speedometerproapp.com/features/ev-obd2): Battery charge, health and cell data for 105 electric and hybrid models. - [OBD2 live data explained](https://speedometerproapp.com/features/obd2-live-data): What each engine reading means, what normal looks like, and why it matters. - [OBD2 on CarPlay](https://speedometerproapp.com/features/obd2-carplay): Live engine data, trouble codes and engine stats on your car’s screen.