BMW 520D 2007 E60 - Tow bar get rid of error message

[Jaman42]

Hi!

I have refurbished my tow bar since I had a gear malfunction in it's gearbox. Now I'm trying to get rid of the error message.


I was hoping it would help me to reprogram the AHM module since it seemed to have something to do with the tow bar but it made no difference. I believe the module that controls the tow bar is called AHV but I can't see it in the list of modules in INPA, but there is perhaps another module that controls it?


I read the instructions in TIS to install a new AHV module and when the module is not initiated you hold the button to pull out the tow bar completely and then holding it again to retract it. It should then be initiated and the LED on the button should turn green.


I do not really know how to put the module in an uninitiated state. Perhaps by removing it from the car with ncsexpert and then add it again? Should I reprogram any other module perhaps?


Thank you for tips and ideas, I can't believe that I have to buy a new AHV module just to repair the tow bar?

[jtbgonesailing]

If you disconnect the battery's negative cable for 15-20 minutes, this will reset all modules in the car. Not saying it will work in your case, but well worth a try.

Good luck,
John

[Jaman42]

Thank you for the suggestion, I tried disconnecting the battery for 20 minutes and then cycled the tow bar but couldn't get any green light. I also tried to change the VO removing $3AC, I wasnt able to find $235 in the list, not sure if I did it the right way I have to do some more research on NCSEXPERT I think. Am I right if I say that the VO is stored in the CAS and LMA modules?

[Jaman42]

I did post an answer already but something must have happend.

I did try to disconnect the battery for 20 minutes but still the same. I have tried to remove $3AC from VO list and updated CAS and LMA but I still got the error message when starting the car. I thought something went wrong when writing the VO list back but when I read the VO list from CAS and LMA $3AC wasn't there so it looked like it worked. Since that didn't work I added it again and then updated the AHM module but still the same error message and the button keeps flashing red.

I was thinking I wouldn't get this message if I remove the module from the VO list so I am not sure whats going on there. I read I should also remove $235 but that isn't even in the VO list.

Here is my VO list:

#0307 $1CA - DUMMY_SALAPA
$2SB - BMW LA WHEEL, START SPOKE 242
$302 - ALARM SYSTEM
$346 - CHROME LINE EXTERIEUR
$3AC - TRAILER COUPLING
$428 - WARNING TRIANGLE AND FIRST AID KIT
$442 - DRINK HOLDER
$465 - THROUGH-LOADING SYSTEM
$470 - ISOFIX-SYSTEM
$494 - SEAT HEATING DRIVER/PASSENGER
$4BX - INTERIOR STRIPS, HIGH-GLOSS, GREY
$502 - HEADLIGHT CLEANING SYSTEM
$508 - PARK DISTANCE CONTROL (PDC)
$522 - XENON LIGHT
$534 - AUTOMATIC AIR CONDITIONING
$540 - CRUISE CONTROL
$548 - KILOMETRE SPEEDO
$698 - AREA-CODE 2 FOR DVD
$842 - COLD-CLIMATE VERSION
$850 - ADDITIONAL EXPORT TANK FILLING
$851 - LANGUAGE VERSION GERMAN
$863 - DEALER LIST EUROPE
$877 - OMISSION OF NON-COMBINED OPERATION
$885 - OPERATING INSTRUCTIONS, SWEDISH
$9AA - OUTER SKIN PROTECTION
%0475 - Paint code?
&LCSW - Interior material?
*NX11
-B080 - Battery?

This is the modules showing up in NCSExpert:

ABG - AirbagAHM - Trailer Module
CAS - Car/Comfort Access System
CID - Central Information Display
DSC - Dynamic Stability Control
DWAI - Alarm?
DWAS - Alarm?
EKP - Controlled fuel pump
IHKA - Integrated heating and air conditioning system
KBM - Body Basic Module
KGM - Body Gateway Module
KOMBI - Instrument cluster
LMA - Light module
MASK - Car communication
PDC - Park Distance Control
RLS - Rain Light Sensor
SZL - Control center for steering column
SZM - Control center for center console

Additional modules listed in INPA:

ZGM - Central Gateway ModuleSIM/SGM - Safety and Information Module/Safety and Information Module
DME/DDE - Digital Motor Electronics/Digital Diesel Electronics
SINE - Siren and tilt sensor
MOSTGW
MMI/CCC - Car Communication Computer
ZBE
KLIMA

Any ideas what to try next?

[Jaman42]

SUCCESS!

20180912_195539.jpg20180912_195756.jpg

Not sure why it worked this time. I once again removed $3AC from the VO and wrote the changes back to CAS and LMA, then I disconnected the modules from the car. Even thou I removed $3AC I got the tow bar electrics failure error but perhaps that's normal? I added $3AC back to the VO and wrote it to CAS and LMA and then I also coded AHM with NCSExpert. Then I removed the key from the ignition and cycled the tow bar once by holding the button and got a green light.

[jtbgonesailing]

Great!!!