My girlfriends formula has been recently throwing a code for a bad quad driver and from what i understand it pretty much means it needs a new ecm.I am having a hard time finding one for a 93 six speed since so few were made that year.My question is:is it possible to buy an ecm for a 93 auto and just change out the chips or does the quad driver pertain to some part or all of the chip??I really know nothing about this.Thanks for helping out a clueless turd gen owner

 

physically the ECM is the same regardless of M6 or A4, but it must be from a 93 and if you grab one from an A4 you need it reprogrammed to M6.

 

93 is a chipped, so he would just need to swap the chip, not get it reprogrammed

 

That is correct. Also a quad driver code (depending on which number. there are 3 of them) could be triggered by a malfunction of EGR, AIR or Carbon Canister.

 

Depending on what QDM fault you are getting, the most likely cause is a blown AIR pump fuse, not a problem with the ECM.

 

Guys thanks for the replies.Shoebox,i looked at your page with the trouble codes on it but i didnt see any that pertained to the quad drivers.I THINK the code was a 30 something.I looked in a chilton manual and thats how i came up with the quaddriver.I want to say it was the #1 driver but i will check her car again when i get home.

 

Sorry you did not see it. It's definitely there. Look in the 1993 specific column.

 

Shoebox,i am an idiot.I wasnt pulling the page over far enough LOL.Anyway that is one of the most helpful pages for her 93 i have ever seen .Thanks again.

 

Ok,i just remembered it is code 26 which is quad driver #1 just like yall thought it was.My question is would it be the relay or just a fuse?If its the fuse is it under the hood or the ones in the car?

 

it is very common for being the AIR, so, first, check the fuse under the hood, if blown, unplug the AIR pump and then replace the fuse



just leave the AIR pump unplugged, will not effect anything else

 

Thanks dave,i will give it a try.

 

350TPI, if you want to look at the diagnostic chart for the 93 QDM failures, I have it listed on the following link:

http://home.comcast.net/~fastbird/Tr...ech%20Aids.htm

DTC 26,27, and 28 are the three QDM codes. Those are direct scans from my 93 Service Manual. Should help you in troubleshooting.

 

I was the AIR pump fuse.I unplugged it and replaced the fuse and it now runs better than ever.Thanks everybody!

 

I just developed that problem. I've blown 3 fuses tonite. I didn't however unplug the AIR before I changed the fuse. Would this affect anything? And another question. How do I unplug the AIR? And will it throw a code?

 

If the AIR pump is drawing excessive current, or if the wiring is shorted, it will continue to blow the fuse. By simply unplugging the harness connector from the side of the AIR pump, it will eliminate the possibility of a shorted or siezed pump from blowing the fuse. Remove connector from the pump = unplug. Good fuse + plus unplugged pump does not produce a code in 93-95 OBD-I.