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View Full Version : 98 A4 non DBW cruise control conflicting results! HELP PLEASE!



ltipcke
08-18-2013, 12:25 PM
Okay ive been using this write up http://forums.audiworld.com/showthread.php?t=168736 and this write up http://forums.audiworld.com/showthread.php?p=2539144 to diagnose my cruise control issue with my 98 A4...

They both give plenty of tests and procedures but my issue is they have conflicting results! [headbang]

My main issue right now is the test for power at pin 11 at the control module with the module unplugged and your testing at just the connector. The first post states that with the cruise stalk switch on and the vehicle powered and testing voltage to ground you should get 12 volts. But the second one says you should have 0 volts at pin 11. WHAT THE EFF!? The second post describes circuit 11 to basically be a normally closed 12v supplied circuit to the control module but then it completely throws that statement out when performing that test while the first posts test should prove that circuit description as accurate since if it is a 12v normally closed circuit well you should get 12 volts there with the key on.

That specific circuit and test is really what im concerned about right now. My stalk switch tests out perfectly at the module connector. But my results on testing for power at pin 11 with key on has yielded me 0v HOWEVER if i slightly press the brake pedal maybe a 1/2-1" down that circuit gets 12 volts then if i continue to press the pedal down further it cuts back out to 0v.

Can someone verify circuit 11s operation for me before i bash my head into the wall?

Thanks very much for ANY help.

PS - Personally i agree with the firsts posts info IF THE CIRCUIT IS A NORMALLY CLOSED 12V CIRCUIT. I just want to fricken clarify the circuits operation before i spend any more time chasing an issue that doesnt exist.

Ryanic
08-18-2013, 07:38 PM
So im going to just ask what seems like a really dumb question.... but did you first resolder the control module? From what i gather youre just trying to figure out why you have no cruise control.... the cruise control module goes bad more often than the one poster said in the first thread u linked.... When i fixed mine about three weeks back i had to replace/resolder my module (under the passenger dash by the air bag).... honestly id try there first lol... the solder gets microscopic cracks and makes ur cruise stop working...

woolveren
08-18-2013, 08:04 PM
Refer to the post #9 in the below thread, even I didn't get that step correct. You will see some more useful steps in the link mentioned by 'Walky'.

http://www.audizine.com/forum/showthread.php/477068-Can-I-drive-without-the-Cruise-Control-Module

But before doing all these, I strongly suggest you to re-solder all the capacitors in the module. Problem might be just a soldering point away. :)

I had two issues in my car; broken CC module soldering and a bad vacuum diaphragm.

Ryanic
08-18-2013, 09:24 PM
http://forums.audiworld.com/showpost.php?p=23825079&postcount=3

Do this first, you're problem might be solved.... Else if you're scared to solder I have a extra control module that has working re soldered capacitors.

ltipcke
08-18-2013, 09:54 PM
Refer to the post #9 in the below thread, even I didn't get that step correct. You will see some more useful steps in the link mentioned by 'Walky'.

http://www.audizine.com/forum/showthread.php/477068-Can-I-drive-without-the-Cruise-Control-Module

But before doing all these, I strongly suggest you to re-solder all the capacitors in the module. Problem might be just a soldering point away. :)

I had two issues in my car; broken CC module soldering and a bad vacuum diaphragm.

Thank you for that post. I will further diagnose using those test that walky recommended as i have not done those yet. And as far as the module goes...ive went over that thing with a magnifying glass and none of the solder joints show ANY discoloration of signs of cracks. Ive dealt with cracked solder joints many of times before and i did not see any signs... But i suppose rewetting the the capacitors just for shits and gigs isnt a bad idea even though they seriously look fine...ill dig into it more tomorrow. Im also leaning toward that relay possibly being bad in the module since i can hear no clicking when trying to operate the cruise. IDK we will see what happens.

Im in the process of lining up a known good module to test so i might just do that before i worry about anything else...

walky_talky20
08-18-2013, 10:05 PM
There are several errors in the AudiWorld writeup, which is why I posted in the other thread to clear some things up. My best advice to you is to look at the actual diagram yourself and test based on that. It's quite straightforward. The cruise module wants to see ground on pin 11 (continuity through the brake light bulbs). 12V+ or open circuit will leave the cruise inoperable.

Remember, you can bypass as many of these safeties as you like for testing. Geez, the Honda guys have DIY's for adding cruise to a Civic that delete nearly ALL the safeties permanently! And I'm pretty sure only like 3 of those guys have died so far.

ltipcke
08-19-2013, 07:14 AM
There are several errors in the AudiWorld writeup, which is why I posted in the other thread to clear some things up. My best advice to you is to look at the actual diagram yourself and test based on that. It's quite straightforward. The cruise module wants to see ground on pin 11 (continuity through the brake light bulbs). 12V+ or open circuit will leave the cruise inoperable.

Remember, you can bypass as many of these safeties as you like for testing. Geez, the Honda guys have DIY's for adding cruise to a Civic that delete nearly ALL the safeties permanently! And I'm pretty sure only like 3 of those guys have died so far.

PHAHAH! thats funny and yeah im in the process of it right now. I have to get to work soon so ill touch back in later today if i find something. I figured there had to be a few things wrong with those write ups the more and more i looked at them and now im kicken myself in the ass for following them SOOOO closely [headbang]

ltipcke
08-19-2013, 07:38 AM
just did a quick test at pin 11. Resistance to ground with key off and with the cruise on is about 3ohms due to bleeding through the brake like bulbs. When i hit the brake pedal meter goes OL when i push the clutch pedal meter goes OL when i turn cruise off meter goes OL and when i hit the momentary off on the stalk switch meter goes OL. When testing for power i have 0v across the board untill i push the brake pedal far enough down to turn the brake lights on then i get 12v at pin 11. That tests out pretty much perfect right?

The more and more i think about it and test. the more i think i have a bad module.

walky_talky20
08-19-2013, 08:09 AM
Yes, that sounds perfect. Key ON and no touchy of the pedals should just a few ohms to ground on pin 11.

If you haven't resoldered the module yet, do it. I've seen a bad one up close. Couldn't tell there was anything wrong with it. And this was upon very close inspection. Resolder and it was good to go.

ltipcke
08-19-2013, 12:08 PM
You guys are the best!

You were exactly right walky...i went over that fuggin board with a magnifying glass and inspected the solder joints. THEY LOOKED FINE! [headbang] But just to be sure and follow your directions, i rewetted those 3 capacitors and to my complete and utter amazement...it fixed the problem. Im still in disbelief that it took care of the problem...

BUT my stalk switch was still bad and absolutely filthy. So im happy i was forced to take apart my steering column and clean the switch the correct way. Now everything works smooth and perfectly and ik my CC system inside and out lol.

Thanks so much again guys for forcing me to rewet those solder joints [:D]

walky_talky20
08-19-2013, 01:34 PM
Glad you got it working. I'm sure you'll agree there is a "magical" feeling when the cruise kicks in that first time.

DeltaAlpha9
08-19-2013, 01:43 PM
I may have to try somethings in this thread on my days off. The only thing I haven't done the DIY fix for yet is the vacuum section of the CC but I got frustrated and quit when I spent a couple hours cleaning my spare stalk only to have it not fix anything.

ltipcke
08-19-2013, 02:05 PM
Glad you got it working. I'm sure you'll agree there is a "magical" feeling when the cruise kicks in that first time.

haha very magical. Still cant believe those joints were bad with how perfectly fine they looked...

ltipcke
08-19-2013, 02:10 PM
I may have to try somethings in this thread on my days off. The only thing I haven't done the DIY fix for yet is the vacuum section of the CC but I got frustrated and quit when I spent a couple hours cleaning my spare stalk only to have it not fix anything.

are you going to override the cruise system by grounding those two pins then supplying power to the motor like the one post says to do? it basically rules out the mechanical/vac side of the system. I did. Its actually kinda fun. Then you can have someone step on the brake or clutch and see the plunger dump. Maybe im just a nerd and like messing with shit like that. I do feel you tho about getting frustrated with chasing problems. Dont give up. The feeling of accomplishment after dicken with something for a few days is priceless [:D]

If you have any questions post up on here. Walky clearly knows what hes doing and now i have a good deal of fresh time spent testing the system [wrench]

walky_talky20
08-19-2013, 02:52 PM
Walky clearly knows what hes doing

Ba Ha Ha! I laughed out loud when I read this.

SRSLY guys. Walky has not a clue what he is doing most of the time. Don't let him fool you. He *clearly* knows how to tie his own shoes, but that's about where the magic ends.