Car Computer Rules and Law Guidelines

If you are planning on installing a car computer in your vehicle or modifying the on-board computer controller, you should be aware of the potential legal ramifications of doing so. Although you are allowed to install a computer or modify the ECU (Electronic Control Unit) computer in your vehicle, there are legal limitations and restrictions you should be aware of. This article will provide information on prohibited modifications and uses and also tell you how to avoid them.

Federal and States Emissions Laws and Car Computers

Many people modify the on-board ECU computers in their vehicles in order to get more horsepower out of the engine or increase other performance characteristics, such as fuel flow or combustion settings. This is particularly popular among younger drivers who want to make their small import cars faster or more competitive for racing. Because most car manufacturers program on-board computers with fuel efficiency and safety in mind, the computers are not optimized for the best performance. Therefore, many drivers have the computers reprogrammed or change them out altogether in some cases.

While the practice is not illegal, some of the modifications that result because of the changes are against the law. Most of the illegal modifications are those that effect the emissions and fuel mileage performance of the vehicle. Any changes to the car's ECU computer that cause the vehicle to fail to meet Federal or State guidelines for carbon emissions or fuel economy are illegal. If the police or Department of Motor Vehicles catch wind of illegal modifications to the car's computer, they can and will impound the vehicle. They will also charge you a hefty fine before you can get it back.

Prohibited Computer Installations

If you want to install a desktop or laptop computer in your vehicle, there are several things you need to consider before you get too far along into the project. For instance, many states prohibit the installation of large computer monitors or screens in the front or dash area of a vehicle. In fact, some states prohibit screens larger than 7 inches (measured diagonally) in cars unless a waiver is approved by the state Department of Motor Vehicles.

Some states will grant waivers for some legitimate professional installations of larger monitors in cars if there is a documented need for the device. People that often qualify for this type of waiver are architects, surveyors, or other engineers who frequently use computers in the field. However, some states don't provide any waiver at all and only allow larger screens to be used in police, fire or other emergency vehicles. Larger screens in the front of a vehicle are considered to be a distraction and could cause an accident. Thus, most states have outlawed their installation in the front seat area of cars and trucks. Larger screens can be installed in the rear seating areas without issue.

Removal of Safety Equipment is Against the Law

When installing a computer in a vehicle, you are not allowed to remove or disconnect safety equipment such as hazard lights, day time running lights, or signal lighting. These types of safety equipment are considered to be essential equipment to the safe operation of the vehicle, and most states require that the devices be in good working condition before a vehicle can be approved for operation on state roads and highways. Vehicles without these devices are not allowed to be driven on public roads.