# Diagnosing: Touareg Stepper Motor / Transfer Case Motor and "System Fault Workshop" in MFI



## Zach! (Jan 8, 2010)

Wanted to post this as a bit of a guide for those who may need it. 

Symptoms:
Dead Battery
"System Fault Workshop" warning in MFI
Binding in drivetrain at low speed
High speed vibration in the drivetrain. 

Parts
Stepper / Transfer Case Motor - 0AD.341.601.C

Tools
10mm and 8mm sockets
Socket wrench
Socket extension


My 2006 V8 Treg started to present the "System Fault Workshop" warning in the MFI that many get, usually on deceleration off the freeway.

It then started to lose charge while sitting for short times, and eventually got to the point where it would take a few cranks to start.

I first replaced the battery, but with the issues and MFI warning persisting, used VCDS to scan the rig.

*02039 - Position Sensor in Transfer Case (G39)
008 - Implausible Signal - Intermittent*

With no binding in the drivetrain that I had perceived, I was skeptical, especially due to the existing motor being the revised part number. (0AD.341.601.C )

Either way, I coughed up the 4 bills and ordered a new unit. (0AS.341.601.C), I was able to source it for 374 shipped.










The swap was easy on a lift, and requires only a 10mm and 8mm socket, and one or two extensions.

This is easily something you could do on the ground for a non-lowered or air-ride Treg.










The only trick is alinging the splines of the motor, but it will only fit one way, and you can rotate the motor with a large screw driver to get it lined up to mate to the transfer case. 5 bolts and 2 harness connectors are the only things that need to be removed. 

The difference was night and day! Despite not noticing the "binding" or "tension in the drivetrain" that most report, I was shocked at how smoothly and effortlessly the vehicle now pulls up to speed. The vibrations at a cruising freeway speed are also roughly cut in half. What I had previously associated with a misbalanced wheel was actually the motor, and the quality of ride is dramatically improved. 

So, if you start to notice dead batteries or "system fault" warnings, get your vehicle scanned, this very easy job can save you a lot of headache and prevent leaving you stranded. The faulty stepper motor will slowly discharge your battery while sitting, leading to dead batteries and potentially a stuck Treg! 

Hope this can help someone in the future with the same issue! 
:vampire:


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## mk1gtigirl01 (Jul 22, 2015)

Looks great! Thanks for the information. I'm sure that my stepper motor will need to be replaced in the near future! 


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