2011 A3 no power signal to j285 starts and dies Immobilizer shutting off engine no DSG communication

farnhamassoc

Veteran Member
Joined
Jul 9, 2011
Location
Riverside CA
TDI
06 Jetta tdi, 09 TDI SPORTWAGEN 2011 Audi a3 TDI. VW caddy turbo diesel... Various vw split window busses
I Purchased this project. 2011 A3
Beautiful a3 160k miles TDI with CBEA already know I will do the BSM delete after if figure out this problem
Purchased from people who know nothing about these cars

Problem started as follows
Stopped at a traffic light and the car would barely go to the side of the road. Turned off engine and restarted Car would not go into gear
He took it to a few shops including dealer and determined Mechatronic unit had a problem in it. Dealer wanted to REPLACE trans. However it probably ended with the Mechatronic electronic controller failing. I hear they do that from time to time.
He went out ever other day and started the car started and ran fine just to keep the battery up.
He took it to a trusted shop he has used before that was a bit further away that is why he didnt go there first, they determined Mechatronic unit failure, But then all the dash lights would not turn on. car starts but shuts right off when immobilizer kicks in.
I dont see any codes but VCDS says on several controlers No communication with J285
I try to select the transmission controller and it will not communicate. Something majorly wrong there.


ANY INPUT would be helpful. My first guess is something in the Mechatronic unit is shorting and took out something in the PCM.
 
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