Cruise problem? Need help!

[Buck]

A couple weeks ago the resume cruise on my truck wouldn't work (More so when cold) took truck in to Burtness Chevy,
Cause: switch failure
J6355 powertrain controller-reprogram truck
J6383 switch, park/neutral position switch part#12450016)

I still have the problem but it doesn't happen as often, but during the drive home tonite the cruise wouldn't work at all!

Anyone have this problem? Any ideas on what might be causing it? Does the NSBU switch have any affect on this? I have the "old" black switch (original). I did have the engine die once when I stopped but no codes were set (couldn't trace it)

[bigbobed]

I've had problems that I believe are some sort of problem in the switch assy. Been too lazy to take it in for service.
Pass a slower car with cruise on. Use the right turn lane change switch and it drops out of cruise. Resume works.
Go over a sharp bump and it drops out of cruise. Resume works.
A couple of times cruise wouldn't work at all. Cycle the on off switch several times and it comes back on.

[needbigtruck]

I had the same problem last year in the winter and it's happening again this winter. It's definetly cold related, it goes away after the cab has been warmed up. I thought is was a switch on the push rod for my clutch, since last year I crawled under there and cycled it a bunch of times and the problem went away. The switch disengages cruise when the clutch pedal is pushed in. Both of you have the auto's so it must be something else. I had thoughts it was in the turnsignal arm, because I also had the same expierence as bigbobed, cycle the cruise switch a bunch of times and it works. So far mine has only been when the cab is cold (really cold, like less than 30)and it has only been the resume. I have never had the cruise not work at all. Haven't got much warranty time left, I hope it hurrys up and breaks or just remains a nagging cold related problem.

[2K2AD]

needbigtruck,

It is not clutch pedal related, I have an Allison and you have described my cruise perfectly. I have found that if I adjust the left vent so it heats up the switch, it will work sooner. This makes me believe it is switch related.

Kevin

[needbigtruck]

2K2AD I have not tried the vent thing, but if it truely is in the turn signal arm, I can't imagine what it could be, I mean it's just a switch. May be when it really cold the contacts on the resume switch shrink away from each other and it takes a little heat to "re-make" the connection.

[Swayse]

Mine won't engage sometimes. But if I hit the brake pedel a few time, it will work. I just push it in a little ways and let it snap back. Not saying that's what your problem is, but it's worth a shot.

Pete

[Me4OSU]

Mine does the same as Swayse's. Won't engage until I bump the brake petal hard and then it'll go on. I'll bet its the switches that the brake petal hits but haven't got a look yet. Probably a simple adjustment.

[hdmax(mike)]

Twice mine has not worked, Both times I floored it then let off right away. Then hit the cruise button and wala, It ingaged. I don`t know what is causing it.

[2K2AD]

I know it sounds wierd, but mine does not seem to be brake pedal related. I can engage it regardless of temperature, it just won't re-engage until the truck gets warm inside. This problem was here last winter, gone for the summer and has come back this winter. There is about a seven mile stretch of road that my truck warms up good on, and I fiddle with this thing every morning. It really appears to re-engage sooner if I warm up the switch. It has me pretty confused (not that that is difficult).

Kevin

[Turbo Al]

Buck: Mine would not work at all (once) when I was on my Holidays. Shortly after that the NSBU switch broke and I took the truck in with both complaints. The NSBU was replaced with same type (old style) and cruise control was "could not find problem" sort of response. Since the NSBU was replaced the cruise has worked perfectly BUT I do not know if there is a relationship between the two.
On Edit: My NSBU is on the blink again so I will keep the cruise on as much as possible to see if it Malfuntions at the same time as the NSBU.

[ 12-16-2002: Message edited by: Turbo Al ]</p>

[Turbo Al]

Update:
Been using cruise when ever possible and It has been on twice now when the NSBU switch malfuntioned -- shift indicator lights go dim or out altogether -- and the green cruise control light goes dim or out at the same time, all other dash lights remain on at the normal brightness. So if it's the NSBU causing the dim shift indicator lights then it is directly connected to the cruise control circuit somewhere.

[Buck]

Thats, good to know! ;) The truck is going back in Monday morning. I'll talk to the tech (I know him pretty well) and he knows the D/A trucks very well smile.gif

[Black Dog]

Mine does it too. When I set it in the morning on the way to work, after the first time I hit the brakes it will not resume. You just have to set it again, and from then on it is OK. Kinda seems to be worse when cold, and it works OK at all other times. "Set" always works, it is only "resume" that acts up.

[DmaxMaverick]

Thanks, Turbo Al!

I think you nailed it! My '01 has done it for at least a year now. Only when it's cold (engine/tranny). Once it warms up, works seemless. Doesn't happen in the summer, only when it's below about 40

[HD Hauling]

I have mine not to work both this last summer and now when it has gotten colder.
One evening coming home from a meeting and with the truck sitting outsde for 2 hrs,temperature outside 28 degrees.I had all kinds of problems resting the cruise.
Once I had it set and would bump it up a mile or two an hour it would stop.
One time just for an experiment after the cruise was set I kept on bumping up the mph and counted anywere from 3 to 5 times then it would cancel.
I did that about 3 times before it wouldn't do it anymore.
Sure would be nice if GM would come up with an answer!
Have a Great New Year

[xwing]

When my 2001 2500HD DA is in cold Wisconsin weather, cold in cab, and I use cruise, it SETS fine but sometimes when I try to bump up the MPH by pressing the slide lever on the end of the turnsignal stalk, it instead CANCELS the cruise.
Have to reset it a couple times, and eventually it seems to work ok again, until next cold outing.

[SteveO]

Here Guys,

Hope this helps..

GM has issued a Bulletin about this problem..

"Loss of Cruise Control, Decreased Pedal Dampening or Tip in Driveline Clunk (Inspect Wiring and NSBU Switch) #02-07-30-034 - (09/24/2002)"

What's happening is Circuit 1786 ORN/BLK from the Park/Neutral Start Back-Up (NSBU) switch to the PCM may be shorted to ground, or the NSBU may not be switching correctly and grounding the circuit internally.

The Correction is to repair any short to ground on the 1786 circuit or replace the Park/Neutral Start Back-Up Switch if internally shorted to ground. Also, be sure that the vehicle contains the latest PCM Calibration.

I added this in edit,
If the truck is out of warranty, I would replace the NSBU with a 29540479 which is the tan with shield. The reason is this has been the biggest cause for these problems. It will probably save you a little in the long run.

Steve Overcash

[ 12-30-2002: Message edited by: SteveO ]</p>