E-mail Story
Print Friendly
Friday, July 28, 2000Computer Error May Cause Stalling Car
DEAR CAR CLINIC: I have a 1996 Mercury Villager I bought new. On two occasions on the interstate with cruise control on the engine has died at about 70 mph. Both times the speedometer needle pegged at the top of the gauge.
After the first occurrence the dealer diagnosed a "separated" battery and replaced it under warranty. The second time, last month, the dealer could find no cause but charged me $70 for the privilege.
The car restarts but misses badly for quite a few miles. Imagine having that happen on a fast-moving freeway!
Factory assistance says they can't do anything unless the problem is occurring while at the dealer. When I get to the dealer, naturally, the problem doesn't show up.
Any suggestions?
K.B.B., Los AlamosDear K.K.B.: It's problems like this one that make those of us in the auto repair field wish we had a crystal ball.
If I had to venture a guess I'd say the problem lies in the on-board computer system. It could be a ground problem at the PCM (Powertrain Control Module), or a bad PCM all together.
The PCM controls the engine as well as the electronic speedometer. The PCM could be getting a bad signal from the speed sensor, causing it to thinking the car is running much faster than it really is.
Most newer vehicles have a built-in safety governor that shuts down the engine if it goes faster than the manufacturer has designed it to go. Most newer vehicles also have rev limiters built into them so the engine can't be overrevved and damaged.
I'm afraid I don't have quite enough information to give a more accurate diagnosis, but I would focus first on the PCM. Good luck and thanks for your question.
Rick Jones, Galles Chevrolet, Albuquerque
DEAR CAR CLINIC: The right turn signal on my 1996 Cadillac Seville STS intermittently blinks fast. I replaced a burned-out bulb and it worked fine for a week or two. Now it blinks fast sometimes and at other times it blinks at the normal rate.
The left turn signal seems to not be affected. How can I find and remedy the problem?
Henry, RoswellDEAR HENRY: One thing I have to ask: Has your car been in an accident? If so, check in the area of the repair and see if a ground connection has come loose. If this is not the case, look again for a burnt-out bulb.
These cars have several bulbs in the taillight area. If one of the two or three bulbs is out in the rear, or even one of the front lightbulbs is out, it can cause this problem.
If all the bulbs are in good working order, then you may need to look at the flasher control unit, which I believe is a fairly expensive part as far as flashers go.
One last place where there could be a problem is a loose connection at or in the turn-signal switch in the steering column. This isn't a common problem but it's not unheard of, either.
Rick Jones, Galles Chevrolet, Albuquerque
Answers in this column are provided by Albuquerque-area automotive service shops. Got a question about your car, truck, van or RV? Describe your problem (please be brief!) and fax it to (505) 823-3994 or mail it to Car Clinic, Albuquerque Journal, P.O. Drawer J, Albuquerque, NM 87103.