what the lan system have to do with our cars?? how does it effect are radio? when a aftermarket radio is installed the gmlan wire is unused for the radio.. i've heard that this causes trouble when performing a diagnostic and i also heard that it doesn't.. i need some input thanks

 

GM Lan is the comminication interface used in our cars. when we hook up a scan tool to a vehicle, it communicates to various components through this system. for instance, if you were to install an aftermarket headunit in your vehicle, the scan tool would not be able to comminicate with the radio(obviously) with all new cars, every time i put a new radio in a vehicle at work, it needs to be programmed through out techline termianl using a program called TIS. it should not affect your cars operation but the system might throw a few codes, because each module in your vehicle comminicate to eachother. they actually send each other signals at set intervals to make sure they are capable of responding to confirm the system is operating correctly. the 'codes that it will set are just going to be "u" codes, which are just going to be communication codes. they 'should' not trigger any lights on your instrument cluster, and will not affect the way your car runs.

 

sorry, just re-read your post and i did not really answer your question clearly. it will cause diagnostic problems if trying to communicate with your radio, but the diagnostics will work fine for everything else.

 

so will i need that tool to for reprograming the comp when changing the radio. also what about if i run a wire of the fusebox... will that mess anything up with the communication or is that just a 12volt supply and nothing else?

 

no, you will not need to reprogram the computer because the aftermarket radio will not be recognized. you should be able to run a wire off of your fuse box, try and use an ignition accessorie wire, like the one that would run power to the factory head unit.