A4 buzz as i start moving

[RoadWrath04]

ok, this came up on another thread, and now i'm worried...while talking about the "normal" unique things that an A4 does, i mentioned that mine will "buzz" once i start moving forward (only after turning it on -- if i put it in park, then drive again, it doesnt do it)...it seems almost like the ABS system is "checking" itself...usually about 5-8 ft of movement and it's a quick vibration that i can feel in the brake or gas pedals...please help, i have no idea what this is doing, and the idiot mechanics here (at a GM dealership nonetheless) have told me its normal

[cammed goat]

Kinda sounds like the traction control system from the description. I am not familiar with the A4s though. Might be the ABS pump is on the fritz? Or maybe a sticking caliper? These cars have so many sensors that are linked there could be alot of explanations.

I have heard that the rear speed sensors have been installed too closely on the rear reluctor rings on the half shafts causing the T/C to go crazy. Look under the rear and check the clearance between the rear sensors and reluctor rings with an old credit card. If the card won't fit between the sensors/rings, then the sensors have to be shimmed.

Keep us posted.

[RoadWrath04]

i turn my TC off as soon as i start the car, so i don't think TC has anything to do with it...but that IS a very familiar feel so you might be onto something...no codes have shown up in a GM diagnostic tho...wouldnt a sensor-fail or prob with a sensor send a code???

[cammed goat]

I am not sure about getting a code if the rear sensors are hitting the reluctor rings. This is a mystery.

[sicls1]

abs check system dont worry its normal worry if it gets worse cheers Nav.

[RoadWrath04]

thanks