# B7 A4 - No Communication with Transmission Control Module - Won't Crank



## pyrobecks (Jul 26, 2006)

Make/Model/Etc: 2006 Audi A4 (B7) with Quattro and Tipronic 

Problem: Car Won't Crank, DIS displays "Press Clutch Pedal to Start Engine," VAGCOM cannot open Address 02: Auto/Trans 

Things Leading Up to This Problem: 
Yesterday I noticed that my hardwired radar detector wasn't working. I opened the fuse panel to check the fuses (The Radar Detector and my Radio power on signal wire were added using an Add-a-Circuit to Fuse Location #41 - Auxiliary Heating). Neither of the fuses in the Add-a-Circuit piggyback were blown (I later found a smaller in-line 1.5A fuse was blown causing the radar detector to not work - but that is the least of my problems now). After checking the Add-a-Circuit I plugged it back into Fuse Location #41, and went to close and lock the car, but for some reason the radio was on. Fuse Location #41 has always only been hot when the ignition was on, so for whatever reason it was now always hot. I opened the car back up and tried to start it thinking that maybe it just needed to cycle, and when I turned the key, nothing happens. The inside lights, gauges, headlights, speakers, seats, you name it... all comes on and appears to be operating normally. 

I've since disconnected the battery and let the system reset, opened the ECU box and checked the fuses in there (all Okay), checked all the fuses in the fuse box on the driver’s side (all good there), however I still cannot start the vehicle. When I insert the key the DIS displays "Press Clutch Pedal to Start Engine." 

I am hoping that there is a relay stuck open (causing fuse #41 to always be hot) and closed (causing the Transmission Control Module to not get power), but I don't know where these relays might be, or what wires to check for voltage for the TCM/TCU power. 

Below is the full VAGCOM scan, you will notice Address 02 is absent - VAGCOM is unable to read that controller. 




> VCDS Version: Release 11.11.4 (x64)
> Data version: 20120807
> 
> Thursday,29,November,2012,11:59:22:49612
> ...


 I really appreciate any helps anyone can provide as I'm not sure how to proceed. 

Thanks in advance!


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## matvey (Jun 21, 2014)

Hi, I am new here. I have a b7 (2008), and got the same codes as you. In addition to that, PRNDS isn't displayed... The car seems to be stuck in one gear (that's what I think) Did you ever find a solution for your problem?


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## stan067 (Feb 25, 2010)

u are in safe mode the PRND going blank is the TCM telling you it is in safe mode.
Safe mode is 3rd gear only to prevent over heating and cooking the trans.
Need to have the TCM scanned for codes with VCDS there will be codes to point you in the direction of the cause.
Seek a pro?
Good Luck


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## matvey (Jun 21, 2014)

Thank you! I just made a thread with the scan results ( http://forums.vwvortex.com/showthread.php?6993527-VCDS-Fault-Codes ). However, other times I receive other codes, but these are the main ones that don't get cleared by the VCDS. Could it be that the electrical board right underneath the shifter nob be fried?


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## Fan1s (Oct 6, 2019)

Anybody solve it? I have the same problem, error 01315 in every unit in car, cluster not show PRNDS and I can not start my car. It happend suddenly after one week my car was in garage alone. I need to solve it. Thx


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