To those with some mechanical knowledge, any idea WTF is up with my truck?

[vi edit]

I've got an 8 month old 2000 GMC Jimmy 4x4. Yesterday I was cruising down the highway with the cruise set at 65MPH. At one point the cruise shut itself off. Didn't really take much notice to it, just set it back on again. Well, about 5 miles down the road, the cruise shut itself off, my parking break and ABS lights came on, and my speedometer died.

Ooookay, that's nice I thought. I pulled off at the exit and came to a stop. Went to make a right turn and tried to get up to a speed of 45MPH to keep pace with the other traffic on the street, and now my vehicle is stuck in first gear. It's an automatic and won't upshift.

Grooovey.

So now I'm stuck with a vehicle that has no working speedometer and won't shift out of 1st gear. It's weird because all of my other gages work. The oil, engine temp, and tach all work fine. My radio works fine as well.

I'm guessing that it's something electrical, because almost all of those things that crapped out have an electrical control of some sort. I checked all the fuses and they look fine. Is the whole brain box shot you think?

I've got to try and get it into the shop tomorrow if I can.

 

[ElFenix]

waranty work time.

 

[cryptokid]

GMC-american
thats whats wrong.

 

[Alienwho]

<< GMC-american that's what's wrong >>


oh please...

 

[frizzlefry]

Damn. That sucks. If your geras don't switch, I think its a computer problem. They may just have to replace the chip and see if that works. Just take it in. They'll look at the diagnostic codes and everything is under warranty so I wouldn't worry too much about it. My Alero crapped on me one night. It sounded like the tranny busted or something. But I had it towed to the dealer at midnight. Next day, went to check it out and they said it was working find. Turned out that since I was parked on a slight incline, the gear kinda just slipped. But was that a sound! Like a big BOOM!! Anyways good luck to you. I don't think I'll get domestic again. Looking at the WRX for my next car.

 

[Sensemann]

must be intel inside, huh?

 

[DaveJ]

I had something very similar happen to my Saturn (speedo and tach stopped working, trans began to shift roughly) just before my alternator died... if it can't put out the correct voltages the computer (which controls just about everything) begins to do weird stuff. I'd have them check your battery, it might need replacement too...

Dave

 

[bacillus]

<< must be intel inside, huh? >>


no, it's the software, windows ME! :Q

 

[vi edit]

Believe me, this is THE last GM product that I'll buy. I'm actually hoping that it's something serious and they can't fix it so that I can lemon law it. I swear this damn thing is possesed. It's been hit twice, hailed on once, and been in the shop a couple times already. I have an actual fear that I will die in this vehicle

 

[cryptokid]

put a little sawdust in there and itll break down in a jiffy.

 

[vi edit]

Alternator huh? That's what I thought too at first...until I couldn't get it to shift out of first. I had an alternator die on an old Grand Am that I used to have. All gauges died, radio quit working, and lights didn't work. Don't think it's the alternator in this case. Lights are still bright, and my radio and all but one guage work just fine.

As far as being a battery problem, it's only 20 months old, so I don't think it'd be that big of an issue either.

 

[Slacker]

<< I had something very similar happen to my Saturn (speedo and tach stopped working, trans began to shift roughly) just before my alternator died... if it can't put out the correct voltages the computer (which controls just about everything) begins to do weird stuff. I'd have them check your battery, it might need replacement too... >>



Very similar to what I experienced with two gm vehicles before the alternator died, including weird trans symptoms, with computer controlled vehicles anything is possible, the computer goes nuts when it doesnt get the right signals.

 

[Pacfanweb]

First of all, take it to the dealer, pronto, before something else gets messed up.

As far as what's wrong, with the symptoms you described, I'd say the rear speed sensor is bad. That's the only thing I know of that affects the speedo, trans, and abs at the same time.

Should be a pretty easy fix, no big deal, as long as it hasn't damaged anything else.
Don't judge all American or GM cars by this one, GM trucks are pretty reliable usually, but they are man-made and therefore they do break.

EDIT: Is it 8 months old or 20 months old? You said both. Either way, you have no case for lemon law that I can see, unless you've had the same problem several times with no fix.
Also, the battery can't cause the problem you are describing. If it is running and the alternator is charging, then it will run perfectly until shut off, THEN the battery matters.

 

[db]

Post your question here. You won't get a real fast responce, but it should be worth it.

(I don't know anything about it, but it could be your alternator belt, fuse, or obscurred ABS wheel speed sensor reading (ie dirt).)

 

Several possibilities;
1)Defective vehicle speed sensor. (Sends signal to speedo and transmission ecm)
2)Voltage surges from defective instrument panel voltage regulator.
3)Defective ecm
4)Bad ground(s)

Immediately return your vehicle to the dealership for warrenty repair.


Good Luck

 

[Rebels7]

Sounds like you have a loose/leaking vacuum line on you transmission modulator.

 

[SuperSix]

<< So now I'm stuck with a vehicle that has no working speedometer and won't shift out of 1st gear. >>



Smacks of a problem with the VSS (Vehicle Speed Sensor).

VSS is used by all the systems you are experiencing problems with.

More than likely if it is a VSS issue, the sender in the transmission is bad, or there's an electrical failure in between the tranny and the ECM.

 

[Sluggo]

I would have guessed a vacuum leak somewhere, but it appears that there are more knowledgeable people here than myself.

 

[vi edit]

Thanks for the replies guys. Glad to know that it's *probably* not something incredibly serious.

Pacfanweb, I said the battery was 20 months old because the vehicle had been on the lot for a year(2000 closeout in 2001), but I myself had only owned the vehicle for 8 months.

12 + 8 = 20

I had to run the vehicle for about 20 miles in this condition to get it home. Luckily it wasn't a very busy road so I could keep it running fairly slow. The highest I let the tach hit was 3000 RPM's. The vehicle has a max RPM of 6,000. I also noticed that the Odomoter was froze as well.

 

[Soybomb]

Its most likely not vacuum related because the transmission is computer controlled I imagine and I doubt the tranny control comptuer takes into account any vacuum, besides it wont affect abs and the speedo. I agree with the others, sounds like a speed sensor, thats why the speedo doesn't work, thats why the odometer doest work, thats why its not shifting, etc. Actually the vechile computers seldom go bad.

 

[TripleJ]

<<I would have guessed a vacuum leak somewhere, but it appears that there are more knowledgeable people here than myself.>>

Yeah Sluggo, you don't even know what's making the rattle in the dash!