Jim Grant's Tech Tips
Mazda Protege, Check Engine Light
Q: I have a problem with a '99 Mazda Protege.
It was bought as a Demo and now has 27,000 miles on it. No problems until
now. The check engine light comes on and stays on. There are no detectable
or obvious problems. It runs fine but what could be the reason for the
check engine light? My wife had put below recommended octane gas in it
recently. Could that have done it? I inspected all the fuses and they
were good--this made the light go off for about 4 days. The fuel cap is
tight. What should I do?? Paul
you canít blame your wife for that one. When you were checking fuses you
most likely pulled a fuse that was the power supply for the computerís
memory. With no power, computers canít remember anything. The problem
must be real because the light turned back on. What should you do? Have
your technician plug into the computer and ask it why. After which the
mystery will be gone and the diagnosis and repair can be made.