The high voltage reading could be causing all of these other
problems. A high voltage reading will mess with the computer and can
cause other false codes.

Evidently the voltage regulator is not working and the alternator is
overcharging the battery. This is definitely bad because the battery
can explode if it overcharges.
On these cars the voltage regulator is inside the alternator.

As you said, it is also possible that he has a bad ground. I would
also suspect either of the battery cables, or the wire that runs
between the alternator and the battery.


On Sep 30, 7:05*am, "Shep" <djslj...@capital.net> wrote:
> Find out what is going on with the 19v readings first."Garrett Fulton" <lbful...@alltel.net> wrote in message
>
> news:1acf8$48e01cd1$438cfff7$26049@ALLTEL.NET...
>
>
>
>
>
> >I was trying to help an old friend today with his Buick. '90 Buick Century
> >with the 3.3 liter V-6. *I pulled the codes for his SES light and was using
> >my OTC Genisys tool. *It showed 3 codes. *One for the throt. pos. sensor,
> >one for high voltage, and one for the elec. spark control. *When he starts
> >the car cold or hot, it immediately revs to about 2000 rpm. *I read
> >throttle pos. for the tps and it was zero angle with the throttle closed,
> >and 100% with it to the floor. *He has had the tps already replaced, but it
> >wasn't adjusted when replaced, but seems to be working correctly. *We
> >pulled the air cleaner off and completely blocked the intake and the engine
> >died, so I don't believe it's a vacuum leak problem. I know that's not
> >anywhere near the best way to check for a vacuum leak, but I had a '92 Olds
> >Cutlass with the 3.4 DOHC with a bad vacuum leak with the same symptoms.
> >When I blocked the intake, the engine still ran at 1200 rpm. *Also, when I
> >read batt. voltage on the tool with the engine on or off, *it read between
> >19.0 and 25 volts. * One time it dropped to 12.2 for a second or two with
> >the engine off. *He said his headlights will pulsate bright to dim
> >sometimes. Also, when I cleared the codes and reread them the tps code was
> >there again, but nothing else. *I just didn't have any more time, or a
> >multimeter. *I'm thinking he's got a bad battery ground but, as I said, I
> >didn't have an ohmmeter. * Am I on the right track? *If any of you guys
> >have a clue about this, please respond soon as I'll be out of the country
> >Tues. morn. and can't read these newsgroups. *And thanks so much for any
> >help from any of you.
>
> > Garrett Fulton
>
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