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Flashing Check Engine light

I have a 2002 Toyota Corolla CE with about 115,000 miles.
While I was traveling on the highway my car started shaking, losing power, and the check engine light started flashing. I drove a mile or two to a rest area because I didn’t want to pull over on the highway. I had it towed home. It starts and idles, but I’m afraid to get it out on the road. I’ll have it towed to a shop, but I’d like to have an idea of what might be wrong.

The possibilities are endless. There’s no way to even guess without at least the fault codes.
But you did exactly the right thing in placing your safety above your car. I commend your choice and wish you the best.

As TSM said, the possibilities are quite numerous. But the shaking, loss of power, and flashing “check engine” light suggest that at least one cylinder was misfiring.

If you’re lucky it could be something as simple as a loose spark plug wire. The same thing happened to me recently, and it was just a loose spark plug wire that was easily replaced.


Clearly, you had a severe misfire, so you obviously have P0300, P0301, etc.

You may have other fault codes. Best to get those codes read out, and post them.

Are the spark plugs overdue for replacement?

If you get them replaced, I recommend only getting the ones that are listed in the owner’s manual

Sounds like it could be an ignition problem, since it occurred after the engine was already warmed up

If this engine has coil on plug (one coil per cylinder), you might have a bad coil

If it winds up being a coil, I recommend a Toyota coil, or at the very least, a Denso japanese coil

Bottom line, the car should be professionally diagnosed and repaired

If you drive around with that check engine light flashing, you will damage the catalytic converter

Any time the check engine light is flashing, you shut off the engine immediately, like you did

Good luck, and please keep us updated

Thank you all so much. I have to leave the car parked until I can save up the cost of not only repair but also the cost of having it diagnosed. It would be wonderful if it’s just a spark plug.

If you could somehow get the ECM codes read, that would give you a heads-up on what the problem might be, and what you need to budget for.

Someone suggested that I take the car to AAMCO because they will do diagnostics for free. Sound like a good plan?


Absolutely not

AAMCO specializes in transmissions

Therefore, they may sell you a rebuilt transmission, whether you actually need it or not

Perhaps you’d be better off bringing the car to a reputable independent shop, and paying them to diagnose and repair it

No, it is not a good plan.
They will do a bait & switch, telling you that it is a simple problem, and then–once they have taken parts off of the engine and or the transmission–they will suddenly “discover” that it is a much more serious issue. At that point, you would have to pay them to reassemble the engine/trans in order to take it to a different shop, and they know that you are unlikely to do this, and that you will probably give them the go-ahead to do the much more expensive–and highly questionable repairs.

Find an independent shop that has been in business for at least 3 years, and you will be much more likely to get…
an honest diagnosis…
a fair price…
superior workmanship.

I have to third the above comments. If you want to get the codes read gratis and not get involved with a repair shop right now, even an independent, most retail auto parts stores will do this as a free customer service. I think that’s a better choice than using a chain transmission repair shop.

I too have to pile on my agreement to the above comments. The standing saying is that AAMCO is an acronym for All Automatics Must Come Out. It is NOT a complimentary comment.

It probably won’t cost much more than $100 at a reputable independent shop to get a diagnosis and estimate to repair. It might just be something simple, like the aforementioned sparkplug. It’s worth finding out.

If you have an AutoZone or Advance auto parts store near you and you don’t live in California, take it there and get the codes read for free, but ask for the actual code, not what the “code says”. The code will be a P followed by a 0 and three more letters. I.e. P0300. Then tell us that code and we can help you some more.

I might make the suggestion that you could invest in a cheap code reader (available from AutoZone, O’Reillys, or even Wal Mart) as a step towards getting a handle on the problem.

Those are not the answer to every problem but they’re cheap (under a 100), easy to use, and can possibly provide a starting point for any diagnosis. It should also last you for quite a while and could provide a code number or two to work with.

No no no, not AAMCO. Whoever told you that is both no friend and no expert. $100 or so for a computer diagnosis at the dealer will tell you for sure what the problem is.

The only reason to ever go to AAMCO is if you work for the Attorney General’s office.

Maggie, check the “Mechanics Files” area of this site for a recommended mechanic near you. Find a good mechanic first, and the rest will go well.

Take it to AAMCO and your nightmare will begin…