ChevyTruckMan84

My Service Engine soon, and my service 4 wheel drive light keeps coming
on. My engine still works fine. But sometimes my 4 wheel
drive dont. Can anyone tell me what could be wrong?

2000 Chevrolet Silverado Z71 ex. cab 5.3 ltr. V8



Aaron Campbell

Silverado_ia

I own a 99 Z71 Silverado, just like yours. I get the Service 4 wheel drive also, I dont get the service engine soon though. But what I've found searching through the net is its a sensor on the transfer case that goes bad. Cant remember the exact name but can find it for you! It's suppose to cost between $35 to $65 depending on your dealers markup. Its suppose to be the fix. When it warms up here this spring I'm going to look into it. If you have push button 4x4 like me mine also is a little touchy about going into 4wheel drive some times, but the more I use it the better it is. </P>


As for your service engine soon light, it could really be anything, the best thing is take it in and have them scan your computer for codes, and see what comes up. usually about $35 to $75 charge for that, once again depending on where you go! </P>


</P>


Good Luck</P>

RATMAN

USUALLY YOU CAN BUY A CODE SCANNER FOR THE COST OF A SERVICE VISIT OR EVEN LESS. THEN YOU CAN CHECK YOUR OWN CODES AND YOU WILL HAVE IT AROUND FOR FUTURE USE. THE MAJORITY OF THE TIME THE SERVICE ENGINE LIGHT IS TRIGGERED BY A BAD EGR VALVE OR OXYGEN SENSOR. THEY AREBOTH PRETTY EASY TO CHANGE<IMG src=smileys/smiley2.gif border="0"></P>

BWEST

if u have an Autozone Store by you you can take it up there and get a
diagnostics test done for free(which dealers and repair centers charge
up to 90 bucks) and they can gell u exactly why its on. Most of a
time its just a bad sensor but they can even clear the code to get rid
of the light.

jimbo310

Another possibility. Have you ever replaced the battery? The electronics in Chevys are highly sensitive to low voltage and before a battery fails to the point where the engine will not turn over other electrical components may malfunction or warning lights may come on. My last 89 Silverado "notified" me of a weak battery when the power windows were intermittent and even after the switches were replaced...no improvement until I put in a new battery. Had a '93 Camaro Z-28 and the ABS light came on despite the fact that the car ran and started just fine. Replaced the battery...and BINGO...problem was solved. A neighbor with a 94 Buick Park Avenue had a problem with the engine light coming on otherwise the car ran fine. Replaced the battery...and no more problem. Best deal on new batteries can be had at Costco, Sam's or Walmart. Get the best most amperage battery you can. Hope that helps. Jimbo<IMG src=smileys/smiley2.gif border="0">

Reggies1956

Ok. It started today. Ihave a "service engine soon" light on, on my 2002 Blazer.I called the Chevy dealership= $89.00 for a test to determine the problem...I then took it to Autozone for the free test, and was told that it appears to be the thermostat or a temp senser. I hada radiator flush with newantifreeze put in about 3 months ago, and since then I've noticed the temp hand is lower at about the 1/4 mark. I had to travel about 40 miles early this morning in the coolest temp of this season. It was about 30 degrees when I started. Then that light popped on. I'm thinking it might be the thermostat maybe hung up in the open position allowing cooler water temps. Should I change the thermostat first ? I was told it might take 20-30 miles of driving afterward before the service engine light would go off. Does this sound correct ?

golfer

While your changing the thermostat remove the negative battery terminal... this will allow time for the ECM to reset andclear the code.

Reggies1956

Thanks for the info. I've bought the thermostat, and just waiting on a warmer day, maybe Saturday.

Reggies1956

Ok, today I had time, so I installed the thermostat. Before that I disconnected the negative post, and reconnected after installation. The water temp is uplooking at the temp gauge, but that darned service engine soon light is still on. Anything else I might can do ?


OK, I think my problem is solved. Apparently the guy at Autozone was correct about driving some after correcting the problem. Tonight I drove about 6 miles, then blink, that service engine soon light disappeared.I think its gone fornow. Thanks again.

laurapenaloza

My service light turn on tonight as well I'm worry. When I read your post I check my gas cap and it was loose. I drove last weekend to Oregon and i think the guy the pump my gas must of not tight up my gas cap. I tight the cap, but light didn't turn off
Any suggestions?