woody3882

I have spent numerous hours trying to get a straight forward solution to resetting the codes on my 94 LT-1 Vette. I found several articles on how to read them on the dash display, but very few and vague on how to Clear the codes out.
So as my way of Thanking the many responders to my past pleads of woes, with solid recommendations, I wrote a solution in reader friendly wording and without spending a pocket full of cash for specific code readers, on how to Read & Remove Codes on the OBD1 & OBD 2 corvette.
I am not a writer, I am just a retired City Cop. This method does work (I did it on my vette last night)
I hope this helps someone out, or answers a few of the unknown questions in regards to the mystique of the OBD system.
Best of Luck
Woody

HOW to Read & Clear Corvette OBD-1 & OBD-2 Codes

1, Car off, Key in the ignition (OFF position)

2, Install a paper clip or jumper between contacts #4 and #12 on the
16 pin OBD-2 connector, or the Top Right and the Bottom Left
terminal for the 12 pin OBD-1 connector.

3, turn key to the ON position (ON, NOT START)

4, watch the dash display as it flashes through the code sequence, I recommend having a pen ready and writing down the codes because you will forget them.

If you see three large dashes “---“ that means there are no codes for that specific module.
As the codes flash they will run through three separate modules showing the Codes for each.
You can determine what module is being scanned by the small number displayed,
#1, #4, or #9
#1 shows codes in the CCM
#4 shows codes in the MOTOR section
#9 shows codes in the ABS/ASR EBTCM

So when you insert the jumper into the terminals, and turn the key to the On position, you will see flashing codes, either three dashes (meaning no codes) or the code numbers will be displayed, The small number (below the codes) 1, 4,or 9 (representing the module being scanned) will also be displayed below the code numbers or dashes

The system will automatically show the codes or dashes for module #1 then continue to module #4, then continue to module #9.
(YES there are only three modules 1, 4, 9)

5, If you made a mistake or missed part of the sequence, all you
have to do is turn
the key off, wait 10 seconds, and turn the key back on and the scan
sequence will
repeat itself from the beginning.

6, After the code scan of all three modules is complete, you will see “1.0” displayed,
If you just wanted the code info, then you can opt out now (or any
time) and turn the key off and remove the jumper.

Or if you want to Remove the codes, do the following

7, remember there are three modules with separate codes in each, so to remove
all of the codes, (or any individual ones), you will have to navigate between the
three modules by doing the following.

When the scan is complete and the 1.0 is showing, press the
TRIP/ODO
button repeatedly until 1.7 appears.
1.7 is the designation meaning “clear codes”.
With the 1.7 now showing, press the ENG/METRIC button until
the three dashes “---“ appears (remember the three dashes means no codes),
confirming you just cleared them for that module.

Now you must go to the second module by pressing the TRIP button, (TRIP not TRIP/ODO) you will see the new second module number appear (1, 4, or 9).

Repeat the sequence as before and press the TRIP/ODO button repeatedly until 1.7 appears. 1.7 is the designation meaning “clear codes”. With the 1.7 now showing, press the ENG/METRIC button until the three dashes “---“ appears (remember the three dashes means no codes), confirming you just cleared them for that module.

Repeat the sequence to advance to the third module and clear them as the first two.


If you see code C-12, it is the designation for CODES HAVE BEEN CLEARED.

Turn the key to the OFF position and remove.
Don’t forget to remove the jumper from the OBD terminal


You should familiarize yourself with the location of the three buttons on the dash you will be using.

TRIP will advance you to the next module
TRIP/ODO will advance you to the 1.7 (clearing code)
ENG/METRIC will clear the code (while in the 1.7)

Cliff Harris

These techniques apply to specific years. See these links for a more general view:

http://corvettephotographs.com/c4vettes/codes.htm
https://www.corvetteforum.com/forums...post1574918379

This link will also be helpful:

https://www.corvetteforum.com/forums...post1576116036

pcolt94

Woody, you have info for the earlier cars. Check this link out for now and if I have more later I will add.

http://www.digitalcorvettes.com/foru...56&postcount=9

gjohnson

How about disco the battery?

pcolt94

That will re-set fuel trim memory as well as the steps for the idle speed control motor.......also.

That works OK for module 1 & 4. But it won't clear module 9, the brake computer (EBECM). Got to go to 9.7 to clear.

rocco16

Or, you could just buy a scanner. That can clear codes, too. Plus it will read codes on all your other cars.

hcbph

Plus the one I have will read and reset both ODb1 & II cars. Just make sure if you need adapters for the various cars you get the ones for yours.

383vett

X2. They are cheap and you can read a stored code in seconds.