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Check Engine warning light . . . . ?

Paul Newman

CCCUK Member
Hi folks.....had my C5 Vette for almost a year now and slowly getting familiar with it (although it has been in selective hibernation for some of the winter months). I've picked up quite a few tips and some helpful advice from YouTube, including the method of clearing the 'Codes' on the D.I.C. but that darned 'Check Engine' warning light keeps popping up from time to time? If I've understood it correctly the main concern is when this light flashes rather than illuminates continuously? Open to suggestions there? I have a CTEK battery charger as used by one Jay Leno, which is fantastic for restoring and recharging my battery. Just after a charge the Check Engine light sometimes disappears, as it does when I clear the D.I.C. codes. However, it still seems to flash up again soon after and the car seems to run perfectly? It is due for a service and M.O.T. fairly soon so I'll get them to check it......known glitch I've heard......what do you reckon? P.S. I hope to join you all at the Corvette Nationals at the end of June this year, get to know other owners and pick any useful contacts for servicing and spares/accessories....cheers!


Well-known user
Instead of deleting the DTCs you need to use via the DIC and write down what DTCs are being reported
and post them here
When is diag mode of DIC scroll through and write those codes down
Normally when the CEL flashes means there is engine misfires.

I do not know how this works in your country but here in the USA when smog testing is done and any DTC shows
and/or CEL is on the car fails testing.
You need to fix the problem, assure no CEL or DTCs tripped before testing is done

Any time you clear the DTCs it may then take 1 or more drive cycles for the PCM to do certain on-board tests
and re-trip the DTC(s)

Using DIC for Diag mode

1. Turn your key to the "ON" position, but do not start the engine.
2. Clear any present messages on DIC by pressing the RESET button.
3. Hold the OPTIONS button down, and press the FUEL button 4 times.
(This will get you into the "codes" section of the DIC)
4. The computer will automatically display all the codes your car has created.
It will cycle through each code every 3 seconds. (write down any codes shown)

Note: Any code that ends in an "H" is a history code (something that has occurred in the past, or C which means current)

5. Once the computer has finished going through all of its codes, press RESET to enter Manual Configuration mode.
It should start with a module and show "NO CODES" or "# Codes."
6. To optionally reset codes once in manual mode, press and hold RESET until is displays "NO CODES."
7. Press OPTIONS to go into the next module (ie, from PCM, or Powertrain Control Module, to TCS, or Traction Control System.)
8. Repeat Step 6 until you have reset all the codes in all the computer modules.

Paul Newman

CCCUK Member
Thanks for that, will see what I can do. Visiting the States next month and doing a road trip along the Pacific Highway.....may pick up some of the smaller accessories for my car too, any recommendations on Corvette spares/accessories shops in and around California???


Well-known user
Informing what the DTCs are would help pinpoint the problems
DTCs starting with P for Powertrain

If the issue is due to multi misfires main DTC is P0300
If PCM can tell which cylinders then DTC as example P301 is cylinder 1 to P0308 is cylinder 8
Best is a OBD-II scanner and looking at what DTCs tripped, and viewing all cylinders misfire parameters to see
if and which misfiring if that is the problem
or look at the PIDs for "fuel Trims" and O2 sensors to see if engine is running too lean or rich.
Would know more once knowing which DTCs are being triggered on

Sorry not sure what Corvette shops are west coast but expect a "Corvette Tax" by them (higher pricing)

FYI, already been in the 90 F deg weather in southern Ca so have some suntan lotion :)


Regular user
I personally have bought VCDIAG VCXNANO (appox 100 USD) from ebay (china) and run Tech2win on my 64bit win 10 laptop wth 15.6" screen .
It is a very nice troubleshooting tool for this car

Ny win 10 64bit pc med VXDIAG VCXNANO.jpg