ABS Module and DTC (Idle)
 

So where to begin.... as I've noticed is a common problem, my ABS light is on. Yes, it is the ABS module. I also have a check engine light on. I took in to the dealership. My concern was more the CEL, especially since having an Audi dealership change the module will cost me $1000+. Car runs well, except for a rough idle.

Now here is what the dealership is telliing me. The rough idle is because of the ABS. Basically, since the ABS is malfunctioning, it tells the ECU to provide less power to the engine. This is also why I have a CEL. The CEL also only flashes when I'm braking (like at a red light) and that's when I feel the rough idle too.

Does this makes any sense???

You either misunderstood them, or they are full of crap. The rough idle has nothing to do with your ABS. Get your car out of there, remove and send your abs control module to get rebuilt for cheap and have autozone scan your ecu for the cause of the CEL for free!

ha ha... I thought so too.... He try to sell me some BS that since the ECU is getting a malfunction signal from ABS module, it sends less power to the engine and that's why I get the DTC. Sounded fishy to me. Probably was trying to get me to drop $1500 on a new ABS. Good thing though is that I'm not getting any misfires while I'm driving. I spoke to another Audi mechanic (an honest one) and he told me he never heard that before. But I wouldn't say it's entirely incorrect. The CEL flashes only when I brake and he said that if that's the case, a faulty ABS module is most likely the culprit.

I'll prolly go ahead and get the rebuilt module. Then get the codes cleared. (Also, after dropping loot to clean cylinders, fuel lines, new plugs and wires, idle is not as rough)

I literally just got my car back from being fixed. The ABS unit was leaking. It cost me $500 to get the whole thing repaired. At first, my mechanic sent it out for a "remanufactured" unit. He specified that there were NO codes being thrown and that the unit was just leaking. He even marked the 2 gaskets that were leaking. The SOB's at the reman place ignored his intructions and simply "swapped" control units. Good thing he checked back with them before they sent it back. He got a full refund minus shipping costs. This reman place is bba-reman.com. For what you need, looks like it will only cost you $139 if you send your unit back and that your issue is the control unit (mine were the gaskets).

A new one IS $1029 at the dealer PLUS installation - which you really can do yourself. See the BBA website which shows picture instructions as well... Good luck!