Hello
been browsing this forum from time to time but never really had the chance to stop in and say hi. Now that my 98 won't start I am hoping someone here can give me a little help. I promise, i just won't come here to use this forum for the help.
My 98 just started acting up yesterday, barely got it home.
When I put the key in and go to turn it over the car will not start, the engine turns over but will not fire. It starts popping up all these messages on the dash display, LOW VOLTAGE, REDUCED ENGINE POWER, SERVICE ACTIVE HANDLING, ETC. and now this morning SERVICE ENGINE SOON. I can hear this buzzing sound from under the hood, that sounds kind of "sickly" for lack of better word. And the strange thing is when i use the turn signals, either up or down I can hear a buzzing sound and the turn signals will not work. The battery is good, just changed it, dome light works good and under the hood light in the engine works good. Also they key FOB (think thats what it is called) will not work, won't lock, unlock, or even pop the trunk. This all started happening at the same time.
The voltage for the battery at the dash is barely showing 8 volts, however it's fully charged at 12.7 under the hood.
Any help you could give would be appreciated. hate to take it to the shop if it's something i can take care of and hate it even more not really knowing what it could be.
Thanks

 

why did ya change the batt ? use a good DVOM and put the probes on the batt and check volts,then probe the hot term .next to elect center,it should have a red cap on it.it sounds like a bad connection,but just in case have someone try to start the car while you look a the meter as its connected to batt

 

It could possibly be a ground problem. There are two connectors under the hood, behind each headlight. Unplug these and inspect them / clean them, if needed. I would also remove the battery and battery tray and inspect under the battery location for any signs that acid previously leaked down into that area. This is common on C5's and will cause problems.

CG

 

Thanks for the replies. Actually i put an optima battery in the car, there was nothing wrong with the old one but it was 4 years old so just thought I would upgrade to the Optima.
I'll check things out with a volt meter again but haven't found anything out of the norm yet and I'll check those grounds out...
Thanks again

 

From my experience, when it says "low voltage," it's time to replace the battery. There are some radar detectors out that will also display low voltage, meaning the same thing...battery is ready to sh-- the sheets.

 

Where exactly would those connectors be? Under the headlights as your looking into the bay? So far the battery tests out fine, even under load. The Optima battery is brand new. When i turn the key on nothing on the dash moves, usually all the gauges will move FULL right than back to normal readings, now nothing. The tray is clean under the battery, no acid leaks

 

Yea, I thought the obvious also, but the battery checks out fine

 

Well i am starting to wonder whether it is the VATS system. My understanding of this is the chip in the key hasa certain resistance, this resistance is detected and sent to the VATS decoder module, which basically says, resistance is fine, Ok to start.
I was in the garage checking things out and troubleshooting it, I kept inserting the key in the ignition and turning it on, off, on, off, and I was finally able to get the car started....

Where is this VATS decoder module located?

 

From your original post, it is difficult to determine but..........Did the problem start right after you swapped out the battery or was there a period of time AFTER the install of the new battery where all worked as it should???

Looking for "cause/effect"

 

The ground connectors are under the hood, right behind / in front of (depends onyour point of view)the hood struts. You cannot miss them. There are gray / black connectors with black wires coming out of the back.

I doubt that it is the VATS. VATS would only prevent the car from actually starting (starter would not turn over / no fuel to injectors, etc).

CG