OK all, I just purchased a 2004 8 with 20K miles on it about 3 weeks ago. Tonight the check engine light came on and it's a constant light. I dont beat on it (or havent yet) and Im clueless as to what the issue is. Im still waiting for my owners manual. Can someone shed some light on my constant engine light? I will have dealer comments tomorrow.

Dan

 

Well, blinking would be bad. Very bad. Constant could be any number of, literally, thousands of things. It's impossible to know without plugging in a scanner and seeing what codes were thrown.

 

The CEL will ONLY BLINK when it sees a "SERIOUS" problem. Mostly Engine componments.

Most common should be Engine misfire. or something else like Apex seal going out and causing all other problems.

 

Did you fill up just prior to the light coming on? If so, chances are that your gas cap is not on tight or it is faulty. Make sure the cap is on tight and drive the car for a few drive cycles to see if the light goes out. Otherwise, as Sigma says, have someone with an OBDII, CAN-compatible scanner read the error code(s). The dealer is your best bet for that, but some of the chain autoparts stores can do that for you as well.

 

Whoa! Here are the facts...

The check engine light can come on for a wide variety of things. Some are major, some not so major. It's not the end of the world or the end of your your car (there are very few exceptions). Unless you have a way to read the codes, take it to the dealer, they do and can address the problem, and clear the light.

BTW, a CEL that is flashing is what happens the 1st few times a problem occurs, it's called a 'pending code', because it may not repeat itself more than a couple times together in time and therefore the pending code will be erased after a few drive cycles. No harm, no foul sort of thing. If it repeats enough the code becomes 'stored' and the light stays on.

 

Pending codes do not flash. Pending codes don't illuminate the DTL at all, that's why they are pending codes. They might "flash" as in, the light is only on for a millisecond. But they do not "flash" as in a repetitive 0.5 second flash off and on. CEL flashes are usually misfires but can be other serious problems, and if you read the manual it probably says somewhere in there to immediately stop the car if you see a flashing engine light.

 

Obviously.. pending codes don't make a CEL light flash. Problems cause a CEL and that code results in a pending code being saved in the ECU. Repeat that code enough and you have a stored code and a solid light. The dealer or your scan tool can read both saved pending codes or stored codes. And no, the manual does not say immediately stop the car (see above edited post pic. for what the manula does say).

And yes the CEL light will flash for a second or so, that's part of the reason it's there, and I've seen it several times and read the codes afterwards. What would be the point of only a millisec flash that no one could see?

 

OK update....I just got back from the dealer and it turns out that Im pissed off for having to take the day off and loose 200 bucks of work to get my computer updated.

Technically, it said code p2404 which is an update for PCM that pertains to the evap system. Have no idea what it means but it could have waited until the weekend. They could probably come up with a better solution for comp updates than to have the CEL come on....damn

 

EVAP system .... update your PCM. It should be as simple as Gas Cap .... or the whole fuel system. depends.

They should do the update for free. since it sounds like your 04 was on L flash or something.(newest for 04 is the "S" flash, theres no "o,p,or q")

 

I had a flashing CEL yesterday. It flashed for less than a minute then it stopped. I quickly pulled the code with my CANScan but nothing showed up. The car didn't knock and I didn't feel any lose of power. I was thinking it might have been a random misfire but shouldn't I have atleast gotten a pending code or something?

Everything seemed to be OK on the way to work today and No CEL.

 

If you have misfires, there is a place in the ECU that stores counters for various events. Misfires will increment the requisite counter(s). Dealer tech told me (and showed me the screen on his laptop) where his scan tool can access this data and how the counter work... not sure if ours (Scanalyser or Canscan) are able to do that..

 

Yeah, I have an 04' and no auto store could scan my ecu... those little hand held scanners just came up with link errors... the dealership rigged it up different I guess..

 

Same here, tried an autozone and their orange handheld scanner said link error. Probably because they're not CAN compatible.

Is there a TSB for random misfires or anything to get your plugs/wires/coils replaced free?

 

Ive got a September 2005 RX8 231 Manual with a engine light that flashes on occasions only going down hill in 6th Gear around 70-90 MPH little or no throttle (Coasting). Ive been back to the dealer a few times and it doesn’t store any codes until a few weeks back when the engine light stayed. The dealer replaced the spark plugs and did a PCM flash as the code was intermittent mis-fire (P0300).
Well I was hoping that had cured the fault but today going down the coast on the motorway the light flashed on 4 different occasions, All going down hill and the light flashed between 5 seconds - 1 minute in time.

Has anyone else had this same problem or anybody got some ideas what it could be?

Please see Video of light in action......
http://www.modularsolutions.net/videos/CEL.wmv