Check engine light flashing but doesn't stay on

[AWDPetmitsu]

On OBDII cars, if the CEL light flashes due to misfiring or some other situation and doesn't stay lit, does the ECU store a code that can be retrieved with a scan tool? The dealer says that they can't find any signs that the CEL ever came on.

[AndyTsI95]

Originally posted by AWDPetmitsu
On OBDII cars, if the CEL light flashes due to misfiring or some other situation and doesn't stay lit, does the ECU store a code that can be retrieved with a scan tool? The dealer says that they can't find any signs that the CEL ever came on.

Id say you have a short... Does it come on when you hit the breaks or go over a bump? My friends honda did that everytime he pressed in the clutch or brakes... then went away.

[Hanzuki]

a flashing check engine light means that someting is seriously wrong and damage to the engine or cat can and will occur if you keep driving it. If the dealership cant find a code then they are dumb lol. a flashing cel is stored and can only be erased if the battery is unplugged for about 10 seconds or more.

[Boosted3000GT]

Originally posted by Hanzuki
a flashing check engine light means that someting is seriously wrong and damage to the engine or cat can and will occur if you keep driving it. If the dealership cant find a code then they are dumb lol. a flashing cel is stored and can only be erased if the battery is unplugged for about 10 seconds or more.

Hmmm, I was always under the impression that a flashing CEL was a soft coad, and a steady light was a hard code... You SHOULD still be able to get the code out if it's been flashing, but if the problem is repaired it will go out, with a hard code (steady CEL) you need to clear the code before it will go out, even if you've repaired the problem...

Lust my .02

[AXiS]

Originally posted by Boosted3000GT
Hmmm, I was always under the impression that a flashing CEL was a soft coad, and a steady light was a hard code... You SHOULD still be able to get the code out if it's been flashing, but if the problem is repaired it will go out, with a hard code (steady CEL) you need to clear the code before it will go out, even if you've repaired the problem...

Lust my .02

That's what I thought, too. I don't think they would make a flashing code more severe because a lot of people wouldn't notice the flashing until it was too late. The solid light you will notice because it's damn annoying.

[moneypit]

actually, on OBD II vehicles, it means your ecm is detecting a condition which could potiently damage your catalytic convertor. that's all it means.

[greenstreak]

Originally posted by Hanzuki
a flashing check engine light means that someting is seriously wrong and damage to the engine or cat can and will occur if you keep driving it. If the dealership cant find a code then they are dumb lol. a flashing cel is stored and can only be erased if the battery is unplugged for about 10 seconds or more.

I don't believe that you are right. A flashing check engine light isn't the meltdown indicator as you seem to be suggesting.

I'm sure that a dealer knows how to pull a code as well. If there was one stored it would be found. That tells me that the flashing cel doesn't get stored. That said, I have never seen a flashing CEL.

[GSXtsy]

Do you have an aftermarket chip in your ECU that would flash the CEL because of a high knock count?

[Taboo]

Originally posted by greenstreak
A flashing check engine light isn't the meltdown indicator as you seem to be suggesting.

He, he..

Flashing CEL mostly indicates a major mulfunction of the emission control system caused by misfire in one or more cylinders.

[Boosted3000GT]

Originally posted by Taboo
He, he..

Flashing CEL mostly indicates a major mulfunction of the emission control system caused by misfire in one or more cylinders.

Could a failing fuel pump cause this? my buddies focus flashes the CEL once in a while and it runs like dog shit, but only under a load... It'll hit 3K rpm and fall flat on its face, feels like fuel cut... I know they have a masive recall campaign to replace the fuel pumps because they are notorious for going bad. I talked to a service guy at ford and he said that's not the problem. He tries convincing me that it's the rev limiter. AT 3000 RPM!?!? I tell him he's full of shit and he says that the fuel pump couldn't cause a problem like that. I tell him that when you free rev the motor that it'll hit 6-7K before the limiter kicks in... So he tells me that the engine is probably toast because we've free reved it a few times to see where the limiter kicks in. I tell him that I'm willing to put money on it being the fuel pump and if I'm right, he pays me AND does the job... He says.... No...


What do you think Taboo (writing out a check for 5 bucks)??? I'm thinking that under a load the fuel pum needs to deliver more fuel and it's starting to go bad and won't flow enough. Would that cause a misfire in multiple cyliners tho?

Any info would be appreciated.

Mike

[AndyTsI95]

I had a misfire and the CEL stayed on... Maybe it was a big enough one to keep it in the computer.

[AWDPetmitsu]

actually, on OBD II vehicles, it means your ecm is detecting a condition which could potiently damage your catalytic convertor. that's all it means.

Flashing CEL mostly indicates a major mulfunction of the emission control system caused by misfire in one or more cylinders.

Both statements are true. I did a little reading and I think I know what's going on. When the CEL flashes, it indicates a condition exists which can potentially damage the catalytic converter, such as a misfire, or mutiple misfires. A flashing CEL is an indication of a more serious condition while a steady CEL indicates a less serious condition exists, such as a faulty O2 sensor or a loose gas cap. The reason why the dealer couldn't find any codes is that in some cases, if the car completes a certain number of driving cycles without a reoccurrence of the problem, the freeze frame of the CEL will be erased.

The possibilty of a short as stated is also plausible, but very unlikely.