Definitive solution to repair cruise control module 5GA 004 397-16
01-23-2010, 11:38 AM
#22
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A6 cruise control unit
[QUOTE=nm3210;23818657]Sorry to bring this back from the grave, but this helped me solve my cruise control woes! I'll help by adding a few pictures to help other people (most notably the pins of the capacitors that need to be re-soldered):
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Sorry what???, lucky me you came back with the pictures, I had taken unit apart twice looking for any anomalies on the board but i did not see anything at first, then I saw your pictures and it gave me another hope. I removed again even though i did not see any crack or cold joint, I resoldered the entire board just in case, and it WORKED, Thanks very much for going an extra mile by publishing the pictures BTW very well taken.
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Sorry what???, lucky me you came back with the pictures, I had taken unit apart twice looking for any anomalies on the board but i did not see anything at first, then I saw your pictures and it gave me another hope. I removed again even though i did not see any crack or cold joint, I resoldered the entire board just in case, and it WORKED, Thanks very much for going an extra mile by publishing the pictures BTW very well taken.
01-23-2010, 11:41 AM
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01-24-2010, 06:31 PM
#24
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My wife and I both have 1999 A6s, so I had two modules to view. I use my cruise control all the time, my wife almost never. My cruise control started exhibiting the normal problem - it would kick out after a half hour of use, and would not work again until it was off for some period of time. So, I pulled both my module and my wife's, and looked at both.
As others had mentioned, at first nothing appeared amiss. So, I took them on the porch and had a good look in very bright sunlight. And then I found it...
The problems are due to solder fracture!
Look carefully at the solder joints for C7, C9, and C11. These are Wima red capacitors. If you get the light right, what you will see a very very faint ring around the solder joints, centered about 0.5mm distant from the lead.
To repair the board, you first need to remove the resin coating that covers the solder. You can use a burnishing tool or a small screwdriver. Get as much off as you can. Then, heat the leads, melt the solder, and add a bit of new solder. This fixed both of my modules, and I've gotten about 8 hours of problem-free use out of my cruise control since the repair!
I surmise that the reason for the problem is that these capacitors are placed directly on the PC board, and have no expansion/contraction capability. Thus, as the seasons change (or cabin temp changes), the leads push and pull on the solder. At some point, the solder fractures, making an intermittent connection, and one that is sensitive to temperature. [I use to see this type of failure a long time ago when I was a field service engineer.]
This failure will occur whether you use your cruise control or not - its due to ambient temperature changes not usage based changes [thus the identical failures on my two 10 yr old units.]
David
For googlers: how to repair 5GA 004 397-16 5GA004397-16
As others had mentioned, at first nothing appeared amiss. So, I took them on the porch and had a good look in very bright sunlight. And then I found it...
The problems are due to solder fracture!
Look carefully at the solder joints for C7, C9, and C11. These are Wima red capacitors. If you get the light right, what you will see a very very faint ring around the solder joints, centered about 0.5mm distant from the lead.
To repair the board, you first need to remove the resin coating that covers the solder. You can use a burnishing tool or a small screwdriver. Get as much off as you can. Then, heat the leads, melt the solder, and add a bit of new solder. This fixed both of my modules, and I've gotten about 8 hours of problem-free use out of my cruise control since the repair!
I surmise that the reason for the problem is that these capacitors are placed directly on the PC board, and have no expansion/contraction capability. Thus, as the seasons change (or cabin temp changes), the leads push and pull on the solder. At some point, the solder fractures, making an intermittent connection, and one that is sensitive to temperature. [I use to see this type of failure a long time ago when I was a field service engineer.]
This failure will occur whether you use your cruise control or not - its due to ambient temperature changes not usage based changes [thus the identical failures on my two 10 yr old units.]
David
For googlers: how to repair 5GA 004 397-16 5GA004397-16
Hey thanks alot for puting this up. i just got a 99 A6 and i have no idea where the cruise controll unit is. could you help me out? thanks!
01-24-2010, 07:29 PM
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07-01-2010, 03:44 PM
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I have a 2000 A6 and the module is NOT behind the glovebox .. only headlight distance module and some other module fastebed to a bracket .. and there is the air bag and a bunch of climate control motors ... any other ideas ?
03-02-2011, 10:53 AM
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bringing this back from the dead.
but i have it all apart and i am seriously not seeing anything wrong with mine. but you all said it is very hard to notice. do any of you guys have pictures of before and after? not the sharpie painted one. or even an after pic might help just to make sure on my end.
i have a 99 a4 avant. no cruise. obviously.
but i have it all apart and i am seriously not seeing anything wrong with mine. but you all said it is very hard to notice. do any of you guys have pictures of before and after? not the sharpie painted one. or even an after pic might help just to make sure on my end.
i have a 99 a4 avant. no cruise. obviously.
03-02-2011, 11:09 AM
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bringing this back from the dead.
but i have it all apart and i am seriously not seeing anything wrong with mine. but you all said it is very hard to notice. do any of you guys have pictures of before and after? not the sharpie painted one. or even an after pic might help just to make sure on my end.
i have a 99 a4 avant. no cruise. obviously.
but i have it all apart and i am seriously not seeing anything wrong with mine. but you all said it is very hard to notice. do any of you guys have pictures of before and after? not the sharpie painted one. or even an after pic might help just to make sure on my end.
i have a 99 a4 avant. no cruise. obviously.
03-02-2011, 11:47 AM
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thanks for the quick reply.
i was just asking for a picture to make sure its done correctly. ive soldered before but just making sure i dont do to much or too little.
also some one previously said they could see a "small" difference in the modules when comparing them in the bright sun light.
just trying to cover myself pretty much
i was just asking for a picture to make sure its done correctly. ive soldered before but just making sure i dont do to much or too little.
also some one previously said they could see a "small" difference in the modules when comparing them in the bright sun light.
just trying to cover myself pretty much
03-02-2011, 02:43 PM
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Well at least you're not completely inexperienced at soldering haha.
The solder joint should look like all the other ones when you're all done, it might be a bit shinier just because it was recently re-flown. Personally, I removed the solder from mine, cleaned up the joints a bit, and then resoldered them back together - then again i'm an Electrical Engineer with years of experience of soldering.
All it really needs is to be heated up and then maybe just a tiny bit of new solder (so the flux can clean the joint a bit). You could try plugging the module back into your car even with everything apart and try testing it out. I know it's a huge pain in the butt to put everything back together and to have it not work :-/ Good luck with things!
The solder joint should look like all the other ones when you're all done, it might be a bit shinier just because it was recently re-flown. Personally, I removed the solder from mine, cleaned up the joints a bit, and then resoldered them back together - then again i'm an Electrical Engineer with years of experience of soldering.
All it really needs is to be heated up and then maybe just a tiny bit of new solder (so the flux can clean the joint a bit). You could try plugging the module back into your car even with everything apart and try testing it out. I know it's a huge pain in the butt to put everything back together and to have it not work :-/ Good luck with things!