Car Coding: What It Is and How to Do It From Your Phone

What car coding is, how it differs from chip tuning, and how to code 1,089 vehicles across 52 makes from your phone.

What is car coding?

Car coding is the process of changing the configuration values stored in a vehicle's control units, also called ECUs. These values control how certain features are set, so coding can enable, disable or adjust features that were switched off or set differently at the factory. Car coding does not change engine calibration maps. It works with stored configuration data rather than physical parts. This makes it useful when a feature already exists in the vehicle but is not active or is set to another behavior. The goal is to match the vehicle's settings to the driver's preference or to the intended configuration.

Coding vs. chip tuning

Car coding differs from chip tuning because chip tuning changes engine calibration maps. Car coding changes configuration values in control units instead. It does not do chip tuning, and it does not perform odometer correction. The focus is on enabling, disabling or adjusting features that are already defined in the vehicle's control units, not on changing engine performance maps.

What can be coded, by make

Example settings by make include: Toyota: Panic Function (Wireless Door Lock), Wireless Control, Hazard Answer Back. Volkswagen: Steering side of vehicle, Acoustic feedback if stored by radio key, Start Stop brake adjustment. Lexus: Panic Function (Wireless Door Lock), Wireless Control, Hazard Answer Back. Ford: Extended Play Time, Clock Master, CAN Steering Wheel Control Switches. BMW: Us Sidemarker, Indicator, Coming Home. Audi: Acceleration measurement, Engine data display, FPK gen.2 Design Lock. Peugeot: BSI2010Evo Multiplex Fuel Additive Pump, BSI2010Evo Steering Wheel-Mounted Switch, BSI2010Evo Seat Belt Reminder. Hyundai: Buzzer on arm/disarm, Escort lights, Door lock sound.

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How to do it from your phone

To code from your phone, you need an ELM327-based OBD2 adapter with Bluetooth Low Energy (BLE). The CarCoding app runs on iPhone, Android and Windows, and it is free to download. Plug the adapter into the vehicle's OBD2 port, then open CarCoding and connect to the adapter over BLE. Choose your vehicle and the control unit or setting you want to work with. CarCoding can read coding data and, where available, write coding changes. Coding writing support includes groups such as BMW, PSA, FCA / Stellantis, Toyota · Lexus, VAG (VW·Audi·Škoda·Seat·Cupra), Nissan, Haval, Chery and Lada. Coding reading support includes Ford · Lincoln, Kia · Hyundai · Genesis and Subaru. Review the setting, apply the change, and write it to the control unit.

Make groups with coding support

Frequently asked questions

What is car coding?

Car coding means changing the configuration values stored in a vehicle's control units (ECUs) to enable, disable or adjust features that were switched off or set differently at the factory. Engine calibration maps are not changed.

Coding vs. chip tuning

Chip tuning changes engine calibration maps; CarCoding does not do chip tuning or odometer correction.

Which adapter do I need?

An ELM327-based OBD2 adapter with Bluetooth Low Energy (BLE) is all you need; the app runs on iPhone, Android and Windows and is free to download.

Get CarCoding

Connect your ELM327 adapter, read fault codes, and browse module settings on supported vehicles.

App Store Google Play

The app is free to download.