Rear Ended - Q5 Electrical Issues
08-23-2016, 04:24 PM
#11
AudiWorld Super User
I think the coulomb counter is technically software running on the ECU, which depends on a conventional shunt in that assembly for data. One good location for both, but separate plugs. Shunt wires don't like sharing.
Ages ago a friend of mine had a Fox wagon. Nice car. And one night calls me "I'm about 1/2 mile from home, the car won't run". It turns out that the alternator had blown (requiring a then un-heard-of huge metric socket to access) and the exotic fuel injection system was counting pulses from the alternator to determine engine speed. So, no alternator output? Then we must be parked, shut the fuel supply and turn the engine off.
Yeah...Audi has never considered "limp home mode" to be a useful option. What the hell, you can always call the dealer, 24x7, and they'll bring you a new one, right?
I foolishly thought the corporate mindset might have grown a little since then. My bad.
Ages ago a friend of mine had a Fox wagon. Nice car. And one night calls me "I'm about 1/2 mile from home, the car won't run". It turns out that the alternator had blown (requiring a then un-heard-of huge metric socket to access) and the exotic fuel injection system was counting pulses from the alternator to determine engine speed. So, no alternator output? Then we must be parked, shut the fuel supply and turn the engine off.
Yeah...Audi has never considered "limp home mode" to be a useful option. What the hell, you can always call the dealer, 24x7, and they'll bring you a new one, right?
I foolishly thought the corporate mindset might have grown a little since then. My bad.
I also supplied you the wiring diagram for the battery igniter module. That is tied into the airbag control module, you probably need Audi engineering involved to find out if you pulled the plug to disable the igniter what are you also doing to the airbag controller.
08-23-2016, 04:54 PM
#12
AudiWorld Super User
Shunt or microshunt (in the IC), all the same in the end. Where they put it and how they control the alternator, from the front or rear, is all the same black magic.(G) I really can't convince my browser to make the tiny print on the diagrams easy to read, and the question of air bag interaction is an interesting one. But from what I was told, there is a two-lead plug (plus and minus) that serves the sole purpose of firing off the pyrotechnic charge to blow that link. So, if that plug is disconnected, no power goes to the link, and it cannot be blown. That "shouldn't" have any conceivable effect on the airbags, which are getting a separate and independent signal to fire, unless some engineer really had a warped sense of humour.
That would be like the Three Stooges movie where they go to a mansion as plumbers, and manage to turn the (gas) chandelier into a water fountain.
That would be like the Three Stooges movie where they go to a mansion as plumbers, and manage to turn the (gas) chandelier into a water fountain.
08-23-2016, 06:13 PM
#13
AudiWorld Super User
Shunt or microshunt (in the IC), all the same in the end. Where they put it and how they control the alternator, from the front or rear, is all the same black magic.(G) I really can't convince my browser to make the tiny print on the diagrams easy to read, and the question of air bag interaction is an interesting one. But from what I was told, there is a two-lead plug (plus and minus) that serves the sole purpose of firing off the pyrotechnic charge to blow that link. So, if that plug is disconnected, no power goes to the link, and it cannot be blown. That "shouldn't" have any conceivable effect on the airbags, which are getting a separate and independent signal to fire, unless some engineer really had a warped sense of humour.
That would be like the Three Stooges movie where they go to a mansion as plumbers, and manage to turn the (gas) chandelier into a water fountain.
That would be like the Three Stooges movie where they go to a mansion as plumbers, and manage to turn the (gas) chandelier into a water fountain.
You go out and disconnect it and let us know????
To see the graphics larger, with Internet Explorer, just go to View/Zoom, select 300%
Simplified diagram..........
Last edited by Bob Petruska; 08-23-2016 at 06:16 PM.
Thread
Thread Starter
Forum
Replies
Last Post
mmccll
A8 / S8 (D2 Platform) Discussion
0
01-04-2014 08:56 AM
bscout52
A6 / S6 (C5 Platform) Discussion
0
06-19-2010 03:37 PM
elijahallen
Audi 90 / 80 / Coupe quattro / Cabriolet
8
02-24-2006 01:32 PM