Flashing Service Engine Soon Light

[03WhiteConv]

I had a P1415 come up the other day and thanks to the good folks here I've replaced the check valve and the code went from C to H! So, I was driving it pretty hard yesterday and noticed that in 1st gear at the top of the RPM prior to shifting the engine had a slight knock and the power just wasn't what it should be. Shortly after that the check engine light started flashing and then the light went out. I had just reset the trouble code on the DIC that day and when I check after the flashing light, there were no new codes.

Any thoughts on what that flashing light means? The car has about 30k miles on it and is still bone stock.

 

[Hib Halverson]

If the check engine light flashes on a 96 or later it means there is a problem with the engine emissions controls which will cause exhaust emissions to greatly increase and may cause engine damage if allowed to exist for very long. The engine damage issue is is important to note as you heard detonation at high rpm under high load.

If you do your own diagnostics, extract the all the fault codes and begin solving them using information in the Factory Service Manual.

If you don't work on the car youself, see service help soon.

 

[03WhiteConv]

I do normally do all of my own maint but don't have a box to pull codes yet. Can you recommend one that does the job with out breaking the bank? I'm not ready to trust the local dealership yet...

 

[Toms007]

You can pull the codes yourself...read this thread.

http://www.corvetteactioncenter.com/forums/c5-technical-performance/72535-pulling-codes-c5.html

 

[03WhiteConv]

True that it seems most codes can be pulled via the DIC. I have read on this forum that others have had dealerships pull codes that did not show up on the DIC.

btw I went by AutoZone today and had them hook up their diag tool and it showed no codes even though the light was flashing last night. (then turned off)

I did a quick search for OBDC II readers and came across this one:
OBD-2 Vehicle Explorer Scan Tool Browser

The software is open-source and runs on a laptop connected to the car with a ODBC II/Serial cable. Has anyone used this software

 

[Toms007]

A couple years back I purchased an AutoXray 6000 scanner. When I was having problems with my 94 (this tool would do OBDI and OBDII) it proved invaluable. It was not cheap, but really not all that high priced either. Around $300 IIRC.

By the way, I have not heard of this software. I think that you can get the cable from Moates to hook up you laptop. These are not cheap either.

 

[03WhiteConv]

Update!!

I have narrowed the problem to a misfire (P0300). Could be a ground issue. It only misfires under load, never under normal driving conditions. Anyone know which ground wire would affect that particular function.

Maybe I'm barking up the wrong tree? Suggestions?

 

[03WhiteConv]

All grounds are good and still misfiring. It's possible that it arcing through the plug wires, gonna replace those.

Any other suggestions?

 

[gmjunkie]

I have narrowed the problem to a misfire (P0300). Could be a ground issue. It only misfires under load, never under normal driving conditions. Anyone know which ground wire would affect that particular function.

Maybe I'm barking up the wrong tree? Suggestions?

Thats where a Quality Scanner and somebody who knows how to use it comes in!!
Could be a Plug wire,Plug,any one of the 8 Coils or a dirty Injector!! Could even be a little water in the fuel,or bad fuel!
It happens!!
I had a little problem with a higher rpm miss on my 03 Coupe with about 10,000 miles at the time,started within 15-20 miles after filling up with gas in Charlotte!:eyerole:eyerole:eyerole
After a couple hours of messing with the scanner in data mode and it running fine and then starting the same thing all over again I decided to change the fuel filter and found a little evidence of water! Went ahead and changed the filter and put 1 Bottle of Heet and 1 Bottle of Techron and Toped it off with Fresh Chevron from here in town,Took it out and drove it and about 20-30 minutes later it had quit missing and hasn't missed a beat in almost 55,000 miles!!!

PS. While I'm thinking about it,Check the little short hose on the right side just behind the throttle body at the PCV valve,there bad to crack and cause a small vacuum leak under power that will give you a higher RPM miss and loss of power!!