HUD Basics

Heads Up Display (or HUD) is a technology that lets you view different things like speed, rpm, satellite navigational directions, alerts and warnings without taking your eyes off the road. They appear like a hologram, reflecting off of the windshield. Not only is it one of the coolest things ever offered in a vehicle, it is very convenient for drivers and helps keep your eyes on the road without worrying about if you are going too fast while there is a cop behind you or something like that. All of this keeping your eyes on the road business also makes the roads a safer place to be. The potential to save lives is built right in to the HUD technology. The bad thing about installing a HUD unit in your car, is that there is not really an after-market type of replacement that will do this yet. Currently, about the only way you can access the technology is to purchase a vehicle that is equipped with it. The unit does go bad, and if you need to change yours you will be provided with the basic steps on how to go about changing the display unit.

The head up display unit is located in the top of the dashboard on the driver's side of the vehicle, right in front of where the driver would be looking while sitting in the driver's seat. The first step to getting the display unit out is to remove the trim around it. On some vehicles it might mean just to un-clip some plastic trim, and on others it might mean to remove the entire instrument panel. Once you get the trim out of the way, you are now ready to handle the display unit.

There are some things that you need to be aware of when handling the display unit which usually costs over $2,000, by itself. The main thing to control is electrostatic discharge, or ESD. Uncontrolled releases of static electricity can get in the circuits, and wreak havoc on the mother board and everything else connected to it. ESD can destroy the entire unit without you even knowing it. What will happen is if it does not destroy it right away, it will weaken a circuit until the low voltage caused completely burns it out. They make wrist straps that can protect the unit against this unseen danger. Also be careful not to scratch the lens on the display unit. You can try covering it with a rag or something similar while handling it. There are also optical fibers that carry the signals on many of these units, and taking the precautions to handle them properly is necessary. Once you have all the background information out of the way, you are ready to change the unit out.

Changing the unit is straightforward, and involves nothing much more than disconnecting and removing the old HUD unit, and then connecting and mounting the new one. On the BMW M5, you have to remove some air conditioning ducts to get the unit out, too. Anyways, once the removal and replacement of the unit is taken care of, you have to aim it. A simple way to aim the unit is to darken the windshield, and turn the display on. Then turn the adjusting rods until it sits where you want it. Be careful when twisting on those rods, though! they can break the unit and cause you to have to get a new one. Once the unit is aimed, you have to program it, which usually involves a factory technician's scantool to communicate with the body control computer, and the heads up display unit. Once all of that is done, you can put the trim back over the unit, and you are finished.

Special tools and procedures might be necessary on your vehicle, so be sure to consult a mechanic before proceeding, so nothing goes wrong! One thing to consider is that changing the unit by yourself can save you about $300, and then you can bring it to the dealer to be programmed for an extra $100. So, now you know how to save a lot of money on how to change a heads up display unit in your car.