Hi all, I have recently purchased a 2001 225HP Coupe. One of the problem of the car is that ESP light comes on after I pass 10mph. I purchased the car hoping that it is an easy/cheap fix (replacing sensors). Today I finally was able to get my co-worker to scan the system with his VAG and below are the error codes returned.

01312 Power Train Data Bus 30-00 Faulty

01324 Control Module for all wheel drive (J492) 49-00 no communication.

I have checked the fuse for ESP and haldex and both looks good. Any suggestions on what I should check next?

 

Ouch, may be a bad Haldex controller module. May be as simple as a loose connection or possibly a short in the wiring harness leading to it.

 

I really hope the Haldex control unit is not bad. I did a quick google and cannot find the location of the Haldex unit on the TT. I read somewhere that it is on the passanger side. Can someone give me a link or a picture of where I can locate it? I'll jiggle the cables on it to see. (I am good at that..IT repair!)

 

It's under the car on the side of the Haldex unit #5 in the pic below.

 

Given the situation...can I still drive my TT? or is it a bad idea right now?

 

You shouldn't hurt anything. The Haldex just won't work properly so you are driving a FWD for all intents and purposes.

 

assuming the haldex control unit is bad, what is a good one to get?

 

Lets see if i've learned anything on here. There is a blue controller and an orange controller. I think both of them will even out the distribution of power to all four wheels but the orange one will continue the even distribution even while breaking which will help if you were on the track or in cornering. Hope thats right, if not i'm sure someone will correct me.

 

the controll unit i believe sits above the rear haldex differential. the main harness for it is at the rear of the haldex diff. it is bolted between the diff and the exhaust. if you go underneath the car you can see it. check it there and if not i would pull the main box. you can see the box form the passenger side and see that it looks nearly impossible to get out. hope for the best, but the aftermarket units would be nice. i'm hoping to get one soon. if i do it would have to sell my stock one.

 

Precision, when you said the main box on the passenger side, are you talking about under the car or somewhere inside the car? sorry..my first TT and first time I am doing hands on trouble-shooting.