The problem may be your computer

Question:

I bought a 1998 Pontiac Bonneville in 2001. In February 2007 I replaced the engine with a brand-new crate engine (same as original) from GM.

During the first four months after the new engine was installed I had at least 15 instances when the check engine light came on. I took the car into the mechanic for a checkup and the computer showed no problems.

Around the middle of November 2008 it started again.

The first time, the car shut off completely while being driven. After a few minutes, the car started and was able to

be driven. About three weeks later, after making a turn, the car lost power and shut off. A few minutes later it started again but there was no power steering. The check engine light and check gauges lights also came on. When the mechanic checked the car again the computer showed no problems.

Besides being annoying this is a dangerous condition. Do you have any idea what could be causing this?

Answer:

The computer will normally store a trouble code when it senses a problem, and it will normally tell you that it senses a problem by turning on the check engine light. The problem the computer reads, if, in fact, it’s actually reading a problem, has to do with the car’s engine or drive train controls or its emissions controls.

The fact that your car clearly has one or more problems and the fact that the check engine light is going on, yet there are apparently no trouble codes stored in the computer, may indicate that the problem is, in fact, the computer itself.

Before doing anything, disconnect the battery and leave it disconnected for 10 or 15 minutes before reconnecting it. This should reset the computer and may, if you’re really lucky, solve your problem. If it does not, I would take the car to a dealer or independent shop with an excellent reputation for solving computer problems in late-model Pontiacs.

I’m not personally familiar with such a shop in the Brandon, Florida, area but if any readers are, please drop us a line.