RS-Chevy-SS

Yeah ive read the faq...But where does the "12" and the stored codes flash? Does it flash in the SES light? Is there a certain code you have to read?

85Iroc-Z

iTrader: (4)

Yes you watch the check engine light which will be flashing. For example code 12 will be flash, pause, flash flash, pause.

Gutz

I'm new here to so is there a guide or pattern to figure out which # it is throwing?

Vader

You’ll need a short jumper wire or paper clip. Cut the clip in half so that one end of it is still bent in a “U” shape.

With the engine and ignition turned off, locate the ALDL connector under the dash, just to the right of the steering wheel in the driver's foot well area on some models, and on the left on others, depending on the make and year. There may be a small rectangular cover over the access hole in the lower dash trim.



Insert a jumper tool or the aforementioned paper clip into the 'A' and 'B' terminals on the ALDL connector:



WITHOUT STARTING the engine, turn the ignition to the "RUN" position. Watch the Malfunction Indicator Lamp (MIL) - it will begin to flash. This is also commonly called the “Check Engine”, “CEL”, "Service Engine Soon" or "SES" lamp. The first code will flash three times, and will usually be a code '12'. This is encoded by one flash of the lamp, a brief pause, then two successive flashes of the lamp. (As another example, a "32" would be three successive flashes, a brief pause, then two successive flashes). Each code will repeat three times, so you should see a "Code 12" flash three times. Any other error codes will follow in numerical order, and each code should flash three times. After all codes have been displayed three times, the "Code 12" will again flash three times, then all other codes will follow as described earlier. This cycle will continue until the jumper is removed or the ignition is turned off.

After you have made a note of all error codes, turn off the ignition and remove the jumper immediately. If you forget to remove the jumper and attempt to start the engine with it in place, you could damage the ECM. For this reason you should remove it immediately.

Once you have a note of all error codes, check this file for the decoding:

GM Error Codes.pdf.

RS-Chevy-SS

hey thanks vader....my next question is if the ses came on a couple days ago but has since shut off...will it still flash when i do this? also whats the chance of me doing this really screwing sumthing up?

RS-Chevy-SS

Bump!!

85Iroc-Z

iTrader: (4)

This is the only thing that i could imagine going wrong.

RS-Chevy-SS

Ok kool...I just dont want to fry the ECM...But if everything will be kool as long as I dont start the motor than thats cool

85camaronetta

Im new to this too and i understood all that but i had one question...After you put jumper tool into "A" and "B" do you touch the two ends together? or just leave them seperated? From what i gather you dont touch them?

Thanks, I'm new to 3rd gens and the whole computer thing. My other vehicle is a 67 4x4 so no computer there...no lights at all except the ones that light up my dash. HAHAHAHA

RS-Chevy-SS

From what i understand...You are supposed to have the 2 connected...But done start the motor with them still connected

85camaronetta

Alright Sweet! This is great to know. I knew I had the ALDL connector so I took it to autozone to check the code but they said the only have a scanner for '96 and newer vehicles, so this is awesome to know, plus I have a Haynes manual that explains the codes. I'm all set if it comes on again! (knock on wood that it doesnt)

Thanks, very informative thread!

Stephen

iTrader: (12)

The paper clip works just as well as the Autozone key. My local Autozone checked my codes (I didn't even have a paper clip or wire here) Then asked me if I wanted the key. Just gave it too me!

85camaronetta

Huh? They told me I was s*** out of luck and would have to go to a dealer and get charged big bucks! Wow, I'm a little irritated now. I always have so many problems with autozone. No one there knows jack about anything. (At least not where I'm at) I go in and tell them what I want (part # and everything) and they ask me what vehicle its for, then they tell me "its not right" and "that didnt come on those". I'm lookin right at the part on my vehicle, dont tell me its not the right part!

Wow, ok sorry, rant over.

RS-Chevy-SS

Haha thats sux..but thats a preety kool key thing that stephen has got!!! Man i had a code flash on me about a week ago but i think it would have erased itself from the memory by now....

G0t M4xx 21

I've accidentally started my 91 RS with the jumper wire still in, it doesn't do a whole lot, the SES light will flash rapidly, and the engine runs kinda rich. I shut it off, pulled out the jumper, and it's fine. I think for short periods it won't really do damage, just don't leave it in there and drive the car.

Also if you have a laptop it's VERY easy to make an ALDL to serial cable and download winALDL, it's a free piece of software that's pretty useful in diagnosis as well as performance. If your computer is like mine and doesn't have a serial port, it works fine with serial to USB converters, I got one at my local electronics store for $15

winALDL:

http://winaldl.joby.se/

RS-Chevy-SS

Im sure your one of the lucky souls that didnt have his ecm fried by doing this....

Stephen

iTrader: (12)

Most Autozone employees ARE brain dead. Hunt around, find a good store, and stick with it. Be it Pep Boys, Oriellys, Shuckers, whatever. Find a parts store with competent employees, and keep going there

Next time I go by there, I'll ask if they know how to get more. It appears to just be stamped outta a sheet of aluminum, same thickness as your standard ignition/door key. In one shot, I bet they kick out a few hundred, in one 4'x8' sheet of aluminum!

Any Autozone should have those on hand. Chances are, the employee, but is too stupid to know what it is, what it fits.

RS-Chevy-SS

Yeah the employees are retarded here to at autozone...I found out that the local Napa in town is the best damn parts store in this town....

Stephen

iTrader: (12)

Pretty cool! I'm assuming it can just run full time, then data log as/if wanted?

I might hafta try winALDL!

RS-Chevy-SS

I might hafta try that too......But were can i get the ALDL cable?