Mechanics

COMPUTER SYSTEM ?

2000 Cadillac El Dorado • V8 FWD Automatic • 79,000 miles

. So today my car went crazy. All kinds of electrical things went wrong. All warning messages, gauges, lights, Fan for heater etc. All flashing and blinking on info cluster. (Radio not working), getting messages like (Theft possible) or something like that, (Air bag), (Car may not restart) etc.. Car does start and runs. Turn signals work, headlights, etc work. Fan comes on by itself and wont stop blowing until car is shut off. All comfort controls not working. Gauges not reading at all. Tried to do a self diagnostic using the pass. Off button with the off simultaneously but it will not go into self diagnostic mode to check codes. Tried to have it reset at Advance Auto Parts. Won't read any codes at all. Any thoughts?
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Glakken13
June 6, 2011.



You'll need a professional scan tool to be able to read the modules that control those things.

Wrenchtech
Jun 6, 2011.
Thanks wrenchtech, hey if I take it to a caddie dealer. Does it just need rest or is there more to it? Why did it go haywire on me?
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Tiny
Glakken13
Jun 7, 2011.
Nobody knows until they get into it and see where it leads.

About the only thing you can do yourself is to use an inexpensive digital voltmeter to measure battery voltage while the engine is running. It must be between 13.75 and 14.75 volts. If it is low, suspect the generator. Since the '87 models, GM has had a huge problem with them developing high voltage spikes and with repeat failures. To prevent both, replace the perfectly good battery at the same time. As they age they lose their ability to dampen and absorb those spikes. Besides damaging the internal voltage regulator and diodes, those spikes radiate voltage spikes into the wires taking sensor signals to the computers. That can cause multiple electrical problems.

Another common problem is loose or corroded ground wires, especially where multiple wires are bolted together. Finding those is best left to the professionals. There are many ground wires and locations on the car. I don't want you to have it torn apart and still not find the problem.

Wrenchtech
Jun 7, 2011.
I see, Thank You. Your thr best dude!

Tiny
Glakken13
Jun 7, 2011.

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