Cruise Control disengaging problem
12-21-2012, 06:32 PM
#1
Instructor
Thread Starter
Cruise Control disengaging problem
I’ve read many posts where owners have had a problem with cruise control disengaging after it is set, or owners not being able to set the cruise control after it disengages. I’m sure there is a post that I missed somewhere with pictures, but I couldn’t find it. So in an attempt to help others, here it is with a few suggestions.
In my particular case, the cruise would set OK, but when I drove over a bump, it would disengage and then I couldn’t resume because the switch on the brake pedal "thought" that the brake was still engaged. The quick test to verify that switch adjustment was needed (and not some other cause) is to pull back on the brake pedal with your toes while driving and then try to set the cruise control. That procedure worked, so I knew the problem was switch adjustment.
Below is a picture of a ’00 A4 (automatic) brake-pedal switch area under the dash. To access the cruise control switch, you’ll need to move the drivers seat all the way back then lay on your back with your head on the floor mat. Remove the two black plastic push inserts and spring steel push-nut holding the kick panel in place. If you are wondering what a push-nut looks like, one is shown in the picture acting as a locknut for the brake switch (the lower switch in the picture). For me, the trick that worked to remove the push nut was to use a 90 degree fine-point pick and get the tip under the washer rim, slide it in, then wedge the springs a little so the push-nut slides right off the stub. You should be able to adjust the cruise control switch without removing the push-nut if you know you read through the procedure below. In that case, just remove the plastic inserts and slip your hand in through the gap.
Once you get the kick panel away, the fix is easy. Just wiggle your hand into position with your thumb on the back of the switch (the end opposite the button in the picture) and push the switch forward into the brake support arm one or two clicks. I know it sounds kind of weird, but the switch has a spring-loaded collar (bright white in the picture). That collar lets you push the switch forward, or even pull it back and out of the support assembly. It takes a bit of force to move it, but when you push forward enough, it will click and you’ll be done.
What caused this goofy thing to get out of adjustment in the first place? If you are like me, you may have pulled back on the brake pedal with you toe, and the back pressure on the brake arm pushed the switch back an indent or two thus causing the problem. I’m pretty sure my wife did it – at least that’s what I’m going with.
I tried two tricks. One worked, the other didn’t. I tried to put a push-nut on the upper switch (just like the lower one). Ace Hardware had a ½” push-nut for thirty cents. It turns out that the shaft is a little bigger than ½” and if you try to resize the spring steel with a punch the nut breaks. If you bought an extra and want to try that one too, it will break as well, just like the first. (Also if you look closely at the picture, you’ll notice that the lower switch with the push nut has milled groves and the upper switch does not.)
The trick that did work was replacing the kick-panel push-nut with a plastic thumb nut for easy removal in the future. (I know, calling this a trick is weak, but there may be one other idiot on the forum and I’m trying to hook him/her.) I had a spare plastic thumb nut that was 3/8” x 16 threads-per-inch which is a pretty standard size. The aluminum pushnut stub (see photo) threads easily with a Harbor Freight die-set -- no need for quarter turn, then back off, then advance, just thread the die on and you’re done. The plastic nut, if you were wondering, is the one that comes in most toilet repair kits and it fastens the seat to the base.
In my particular case, the cruise would set OK, but when I drove over a bump, it would disengage and then I couldn’t resume because the switch on the brake pedal "thought" that the brake was still engaged. The quick test to verify that switch adjustment was needed (and not some other cause) is to pull back on the brake pedal with your toes while driving and then try to set the cruise control. That procedure worked, so I knew the problem was switch adjustment.
Below is a picture of a ’00 A4 (automatic) brake-pedal switch area under the dash. To access the cruise control switch, you’ll need to move the drivers seat all the way back then lay on your back with your head on the floor mat. Remove the two black plastic push inserts and spring steel push-nut holding the kick panel in place. If you are wondering what a push-nut looks like, one is shown in the picture acting as a locknut for the brake switch (the lower switch in the picture). For me, the trick that worked to remove the push nut was to use a 90 degree fine-point pick and get the tip under the washer rim, slide it in, then wedge the springs a little so the push-nut slides right off the stub. You should be able to adjust the cruise control switch without removing the push-nut if you know you read through the procedure below. In that case, just remove the plastic inserts and slip your hand in through the gap.
Once you get the kick panel away, the fix is easy. Just wiggle your hand into position with your thumb on the back of the switch (the end opposite the button in the picture) and push the switch forward into the brake support arm one or two clicks. I know it sounds kind of weird, but the switch has a spring-loaded collar (bright white in the picture). That collar lets you push the switch forward, or even pull it back and out of the support assembly. It takes a bit of force to move it, but when you push forward enough, it will click and you’ll be done.
What caused this goofy thing to get out of adjustment in the first place? If you are like me, you may have pulled back on the brake pedal with you toe, and the back pressure on the brake arm pushed the switch back an indent or two thus causing the problem. I’m pretty sure my wife did it – at least that’s what I’m going with.
I tried two tricks. One worked, the other didn’t. I tried to put a push-nut on the upper switch (just like the lower one). Ace Hardware had a ½” push-nut for thirty cents. It turns out that the shaft is a little bigger than ½” and if you try to resize the spring steel with a punch the nut breaks. If you bought an extra and want to try that one too, it will break as well, just like the first. (Also if you look closely at the picture, you’ll notice that the lower switch with the push nut has milled groves and the upper switch does not.)
The trick that did work was replacing the kick-panel push-nut with a plastic thumb nut for easy removal in the future. (I know, calling this a trick is weak, but there may be one other idiot on the forum and I’m trying to hook him/her.) I had a spare plastic thumb nut that was 3/8” x 16 threads-per-inch which is a pretty standard size. The aluminum pushnut stub (see photo) threads easily with a Harbor Freight die-set -- no need for quarter turn, then back off, then advance, just thread the die on and you’re done. The plastic nut, if you were wondering, is the one that comes in most toilet repair kits and it fastens the seat to the base.
