Why would the check engine light in my 2000 Mazda Protege come on?

Question

Yesterday, when I started the engine the battery light came on as did the (flashing) air bag light and continued until I arrived at my destination. Today, while I had already been driving down the freeway, the same thing happened with both lights. Eventually the check engine light came on. As I got off the freeway my car started idling low and seemed to want to shut off at stop signs. I was able to drive it to where I was headed. I will be going to a mechanic tomorrow. I just want to get some ideas of what it could possibly be so I don't get taken. Also, It's a stick shift if that helps.

Thank you in advance for your assistance!

Answer 1

My subaru did that once when the gas tank cap wasn't screwed on tight enough to prevent an evaporation sensor from being tripped. It made everything go haywire...cruise control light flashed non-stop and the check engine light came on too. I thought the car was a lemon and it only had 600 miles on it at the time!

Took the dealer less than 15 minutes to confirm it was an issue with the gas tank cap not being tightened enough and clear the code. Since then, I've had no troubles.

Answer 2

Modern cars are run by computers which tell the engine how much gas to inject, what the timing of the sparks should be, etc. This all changes based on driving conditions - air temperature, density, exhaust gases, grade of gasoline, how hard you are pressing on the accelerator, etc.

To measure these driving conditions and compute the settings, the computer relies on electronic sensors wired into the engine, fuel injection system, and exhaust.

If one of these sensors goes bad or if the wiring goes bad, the computer will get faulty readings for the sensor, not be able to make heads or tails of things, and will sometimes go into bad states, signaling the "Check Engine" display and faulty running behavior.

So you will mostly likely find that a sensor has gone bad.

I once had an '86 car which would cut out at certain temperatures while driving down the freeway. It was due to a faulty sensor wire that failed to have a good electrical connection at certain engine compartment temperatures. It worked at cold temperatures and warm temperatures but not a range of inbetween temperatures. That took a long time to diagnose. On board diagnostics (OBD) are much better now than back then.

Good luck.

Answer 3

I knew this question would come up. It happened to be a few years ago. I was giving my friend's father a ride and he thought he was doing me a favor by pumping my gas. In reality, he damn near gave me a heart attack. He didn't tighten the gas cap enough and the next day my check engine light came on. I panicked because I was on the freeway. Luckily, at the time, I worked for a car dealership so I dropped it off in service when I got there. They ran tests and came inthe office to tell me it was because the gas cap wasn't tightened tightly. I was EMBARASSED~!!! My service advisor/co worker said it is a good thing I work there or they would have charged me an arm and a leg for those tests. Anyway, it MAY be that. To see if it is, tighten your gas cap and unplug your battery for a few minutes. Maybe ten. Then re plug it in and see if that is the problem. It's MUCH cheaper than going to the dealership or a mechanic, plus no time off work. If that's not it, then I'm not sure what the problem is, like they told me when mine came on, it could be one of 2,000 things. So, good luck and I hope that's all it is. :)

Answer 4

Typically, the check engine indicates an emissions-related problem (oxygen sensor, catalytic converter, etc.) BUT it can really be anything that the on-board computer monitors.

From the sounds of it, this seems a bit more significant than just an oxygen sensor. You could have multiple things failing (alternator, air bags, etc.) OR (and more likely if you ask me), there is something not quite right with the on-board computer.

Good Luck!

Answer 5

My check engine light has come on before because I didn't close my gas cap all the way. After I fixed the problem the light did'nt go off until I brought it to the dealership. I thought something was majorly wrong with my car but I think it was all in my head.

Answer 6

your question doesnt answer all the question i woul have for you about your proublem but if the battery light came on previoius to the air bag light this may be caused to aa drop in voltage by the alternator or regulator witch would send a signal to th ecomputer witch will cause the light driver (indicator) to show the light . if you have a local auto parts store you can the system checked for free . auto zone,pep boys,advavanced auto,more call first tell theme you have a obd computer

Answer 7

I've had the same problem. One of your sensors is either damaged or sensing that something is wrong somewhere in your car. For me, it was my fuel sensor. Best thing to do is what you are going to do tomorrow--which is take it to the mechanic to diagnose the problem. However, don't get it checked at the dealer, the charge you WAAAY to much money to fix and diagnose the problem.

Answer 8

The check engine light is just a general indicator to you that you have to take your care in to a mechanic to have diagnostic done to see where the problem is.What they do is to plug this diagnostic machine to your car's computer and it prints out trouble codes for the mechanic to look into these areas.

Answer 9

maybe a sensor. Go get it on the machine for about 75-85 dollars and they will tell you right away. (a mechanic)

Answer 10

check you oil leval and gas. Your engine could also be going bad. How many miles is on ur vehicle?