What does a flashing cel mean. I was driving my 03 last nite to the gym and all of a sudden the cel started flashing for like 10-20 sec then went away. Car runs fine.........

 

Flashing CEL indicates a severe misfire.

So it had no driveability issues? Odd.

 

The technical diagnosis would be a misfire, with possible damage to the three way catalyst. One or more of the codes P0300 through P0306 may be stored in the ECU.

Possible Causes of the Problem

• Improper spark plug
• Insufficient compression
• Incorrect fuel pressure
• EGR volume control valve
• The injector circuit is open or shorted
• Injectors
• Intake air leak
• The ignition secondary circuit is open or shorted
• Lack of fuel
• Drive plate or flywheel
• Front heated oxygen sensor

 

no driveability problem at all. car runs perfect. could it be plugs fouled by oil.

 

The first time I had a coil go a CEL flashed at startup about 2-3 times before it came on and stayed on and the knocking was apparent.

 

Had the same thing, check the valve covers for the ever popular tube leak. My problem was #3 coil misfire, resulting from leak.

My cel flashed, then disappeared, 2 weeks later misfire returned big time.
Limped it to mechanic, 04 cover and #3 coil later runs great. Supposedly you should change all coils when one goes, Decided fa-Q on that idea, 2 months later no problems.

Get the codes pulled and diagnosed before you damage any cats etc. or miss a day of work.

Good luck

 

Was your car running just fine even when the cel was flashing and what did it run you to have the work done.

 

First time light flashed I noticed a slight rough idle, Figured it was caused by -25C temps (eh!). Chose to ignore it. Then about 10 days later, almost to the day I got my code scanner I got the flash, and a misfire P0303,P0300 codes.
Erased the codes, but next day #3 came back bad, so I limped it in.

Cost me $240 or so

My mechanic is pretty kick a$$ with labor charges, But if you just need a coil, the 2,4,6 front ones shouldn't cost too much, but if you get a rear one it will cost an hour or two extra because of manifold and possible manifold gasket replacement.

If you haven't changed your plugs yet, you should since the manifold will be off (if it's a rear coil). If it's a rear coil just go ahead and change the cover because 95% chance #3 or #5 will have the oil tube leak. If not it will eventually so replace.

 

Whenever i reset my ECU and start my car. CEL be gone till i rev, then it'll flash and stay on.

 

Just had same problem on 2003 Maxima and turned out to one of the rear coil needed to be replaced. So will be replacing all 3 rear coils & plugs.