Car Not Start

[marinabrid]

evening all

 

2.8 auto  54 reg  

Well. had no problems in 16 months  then a biggy

turn key,  dash lights on,  except strangley the  footbrake one that tells you to press the brake to let you move from P to D was not lit.  towed home by RAC ,  his scanner said gearbox module failed 

 

got home and put vagcom on,  same code came up  01315   no signal communication

the module is right by the battery on inner wing,  so unplugged it,  not a lot to see   all looks shiny and clean  no water ingress etc,,,  found on other forum that wiring problems are common  but where an dhow do you find the problem !

 

so now stumped.  the actual gearbox module didn't put its fault in the  auto box section of vagcom  which i though odd,.   that module won't communicate according to vagcom,  it always has in the past    so maybe a clue there ?   i found the fault in the abs module for some reason,  same code as the RAC man found

 

so thats it,   tried to find a module but can't find one with same last letter  or other smaller number sequences on the label.

 

any ideas welcome

Thanks

Edited November 1, 2015 by marinabrid

[sparky Paul]

First thing of course, check all the fuses to make sure the gearbox ECU is getting power. If vagcom cannot communicate with it, then the likelihood is that it is either not powered up for some external reason, or the ECU is not well.

 

Hopefully, someone else will be along soon who know something about the wiring loom problems - IIRC the problems occur around the gearbox multiconnector.

Edited November 3, 2015 by sparky Paul

[marinabrid]

Hi there

Seems a little known about subject with few replies !

all i could do was test the plug where it joins the ecu,   there was a 12v supply at pin 22  which is at one far end and the thick brown earth at the other end.  all there other pins in between didn't show,   so i presume power is there.

tried to get n/s headlamp out to look under the battery tray  but seemed jammed,   the grill seems fastened to the bumper somehow so i couldn't get that out,   i don't know if there is a big mounting under the battery tray   there seems a big rubber block  so i didn't want to unbolt that in cash it all crashed down 1

 

so im stumped,      i sent the ecu off to a firm call sin speed    seem to have a good reputation for testing ,, suppose that will eliminate it in the end, he said it will be £50 to test or £250 if it needs repairing,    in one way i hope its faulty   as if not   and it comes back the same  i don't know where to look.

[marinabrid]

to cut long story short,   got ecu back  no faults,  found it is a fuse.  no 5. supplies power to gearbox ecu.   now when i put in reverse  the fuse blows.

have checked tailgate wiring   all good,  bulbs  fuses   tried it with no bulbs and connectors removed   still blows same fuse, 

any ideas as now had no car for 2 weeks.

at least now can drive  but carry spare fuses in case i need to reverse !

anyone know where to look for the rev light switch on an auto gearbox ? and how to test it,

Edited November 14, 2015 by marinabrid

[chromedome]

From what I've read in the past the wiring between the ECU and gearbox can wear through where it runs along the gearbox causing breaks and shorts. Could be worth a look.

[marinabrid]

Hi

Thanks for that, wondered if parking sensors had anything to do with it  as they are engaged with reverse gear as well,   looks like more poking around

[marinabrid]

been at it all day,  found a fault  01236   shift selector lock solenoid    open or short to ground      andy ideas     does it mean the solenoid is faulty or the wiring  ?

[chromedome]

Brake light switch? These have been known to fail. The switch does not only operates the brake lights but controls the gear selector lock. If the solenoid or brake light switch was faulty I would have thought you would have had problems selecting all gears not only reverse. I would still suspect the wiring.

[marinabrid]

Hi

Cant think even now where to start looking,   i know you said the harness round the gearbox. its a 2.8 auto,  to remove battery tray i understand some models you have to jack the car up to support the gearbox,   is this the case,   if it is  I'm stuck as i can't do it at roadside      when it says the  solenoid is shorting to east   does this mean then the wiring or could it be the solenoid itself,  is there a way to bypass,  i have unplugged it from under console but still blows fuse,     checked again wiring in tailgate area ,  stripped it all down   all perfect ,   checked the parking sensor box under seat,   all dry,  unplugged and tested,, still blew fuse., 

then the fault 01236 lever lock solenoid shorting  popped up, hasn't appeared before,   i cleared it   replaced fuse,    could get the fault code again though   even though fuse blew again !

getting a bit frustrated now.

[marinabrid]

trying to check wiring to the lever lock solenoid,  seems to go under the console ,  anyone got wiring diagrams 

[cyborg]

Hi seem to remember that the gearbox is an ag5 also known as 01v on mk2 and ag4 on mk1 .

 

Heres the I depth book on it http://avtopedia.ru/akpp/audi_o1v_o1vl.pdf.

[cyborg]

Hi seem to remember that the gearbox is an ag5 also known as 01v on mk2 and ag4 on mk1 .

 

Heres the I depth book on it http://avtopedia.ru/akpp/audi_o1v_o1vl.pdf.

[marinabrid]

many thanks cyborg

been like this 3 weeks nearly ,, good job don't need it for work 

[marinabrid]

Had a look   but too complex for me, was hoping to see maybe gearbox photos and where switches were positioned, need someone with electrical skills   shorting out somewhere,      if i pull relay that controls auto box and reverse lights  no. 175      the fuse don't blow.,  so problem must be  up to relay i guess

[marinabrid]

finally fixed,.    had to go by trial and error and cut the supply to the rev lights from the relay,   then worked down.  a section near the front  seemed to trip it so i bypassed it and   no more fuse blow,.

then  this caused the reversing sensors to the rear to stop working, must be fed from same supply,   so tapped into that wire at the module under the pass seat, isolated the feed from the relay and all working again. 

so  3 weeks of crap all caused by one fuse and a bit of chaffed wire.  

Thanks for all input ,  bit complex and an auto which not many have to be able to put ideas.

Edited November 20, 2015 by marinabrid

[sparky Paul]

Good news.

 

As chromedome says, the loom wiring and connectors on these is a weakness -  similar issues have cropped up several times before. As you have found, these faults can also result in a great deal of head scratching.

[marinabrid]

indeed     can't work out why a wire in a loom that simply goes behind the dash area and seems well fixed  would suddenly short wires out,   can understand the door sections and tailgate as constant flexing  but wires that don't move !   odd.