99 "Service AWD" Light on

I searched all the posts I could find regarding the AWD light issue, but figured I'd throw this out for opinion.

My Service AWD light just came on today - the truck is a 99 with 97000 miles. I did the "transfer case flush" to get rid of the chatter issue back around 30,000 miles or so, and changed it again right around 80,000. After the light came on, I pulled the ATC fuse under the hood, and can hear a "click" coming from the transfer case when I plug the fuse back in. Not sure if the click is from the encoder motor, but something is definitely engaging. I gave the truck an "AWD" test (pulled over in the lawn and punched it) and it felt like the AWD was engaging normally. With the fuse disconnected, it did a one wheel peel and made my wife a little unhappy with the lawn damage, but hey, winters almost here.

I just pulled the negative battery cable a while ago in the hopes that maybe the computer was unhappy and that resetting it would clear things up. Figure I'll let it sit overnight disconnected and see what happens in the AM.

Just curious as to what others may think, if this is a sign of impending failure of the dreaded "encoder motor" assembly, or if there is something else I should be looking towards. Snow will be flying here soon, and I'd rather not be doing doughnuts during the first storm.

You need to get it on a trans/engine capable scanner and check for codes on it. If you have codes record and post them back.
Clear codes with a scanner and/or command light off and hope it stays off.
If it comes back on recheck for codes.
MT-2500

I Halso Have A 99 Bravada It Has 136000 Miles On Her And My Awd Light Will Come And Go But Everything Drives Normally She Is On Her Second Transfer Case, But It Seems As Though It Happens When I Park On A Non-level Surface That It Will Kick The Light On I Can Drive For A Couple Of Feet Turn The Truck Off And Restart And Then The Light Is Gone ???? Sometimes It Wont Happen For A Couple Of Weeks Sometimes 2 Days In A Row ? I Dont Know What It Is Either ! But Every Thing Seems To Be Running Fine.

My AWD light is on and i lifted it up on jacks to see if all were engaged, all of the wheels were spinning except for the front right. Does that have anything to do with the trasfer case being bad?

Traster4u ^^^
You need to start a new post. This one is someone else's post. Two post in one can get confusing.
Also give more info year make and model and eng and trans and mileage and how many doors.
MT

Anyway, this is the same thing mine does. I think it's normal, as the front differential will transfer power to the "non slipping wheel".

With my Bravada, I narrowed it down to a bad transfer case "encoder" motor. It appears to be locked in AWD, which is fine with me for the winter months....

Biv, your transfer case will bind up and start breaking parts if it stays engaged. At least pull the fuse until snow arrives...a simple switch would be better so you could shut it off before you run off the slick stuff. A toggle switch, 2 small spade connectors, a cheap inline fuse and a coupla pieces of wire. Remove the fuse and insert the wired spade connectors where the fuse spades fit on the fuse panel. Connect the spade wires to the inline fuse and toggle switch. A lit toggle switch will light up when it's on so you can find it in the dark. :naughty:

I did exactly what you described late last week. Worst part was trying to get the wires into the passenger compartment. I put the toggle just below and to the right of the steering column. Had to give the wife "AWD switch 101". This is just temporary until I get around to fixing the transfer case motor, which will hopefully be within the next few weeks.

Any words of wisdom on replacing it? Almost looks like the front driveshaft needs to come off to get it out of there. Then again, I didn't have the new part to see exactly how it mounts.

Tell you what Biv, that switch setup is probably the most reliable/least damaging way to 4WD your Bravada. There no telling how long you'll go without trouble now. Everybody with a '98 and newer Bravada could save themselves much grief by hardwiring like yours.
A lit switch would make 4WD 101 a bit easier.
For the sake of archives, how about making a new post on how you did the whole job for others to refer to easily?

Tell you what Biv, that switch setup is probably the most reliable/least damaging way to 4WD your Bravada. There no telling how long you'll go without trouble now. Everybody with a '98 and newer Bravada could save themselves much grief by hardwiring like yours.
A lit switch would make 4WD 101 a bit easier.
For the sake of archives, how about making a new post on how you did the whole job for others to refer to easily?

I gotta agree with Chris on this one. It ain't elegant but not only does it solve the problem, more importantly it keeps the problem from recurring. My Dad's old farm mechanic would love it. Not as simple as the automatic way it was designed, but it's still better than getting out in the middle of a mud hole to lock the stinking hubs like we used to have to do on our older rigs.

Will do. Look for the new post shortly.

I have a 2000 bravada and when I first got it everything was great. Then one day the awd light came on and took it back to the dealership and he put it in the shop. He had the awd replace before I bought it. Come to find out it was a bad awd motor. So I am pretty sure that is what wrong with yours.







I searched all the posts I could find regarding the AWD light issue, but figured I'd throw this out for opinion.

My Service AWD light just came on today - the truck is a 99 with 97000 miles. I did the "transfer case flush" to get rid of the chatter issue back around 30,000 miles or so, and changed it again right around 80,000. After the light came on, I pulled the ATC fuse under the hood, and can hear a "click" coming from the transfer case when I plug the fuse back in. Not sure if the click is from the encoder motor, but something is definitely engaging. I gave the truck an "AWD" test (pulled over in the lawn and punched it) and it felt like the AWD was engaging normally. With the fuse disconnected, it did a one wheel peel and made my wife a little unhappy with the lawn damage, but hey, winters almost here.

I just pulled the negative battery cable a while ago in the hopes that maybe the computer was unhappy and that resetting it would clear things up. Figure I'll let it sit overnight disconnected and see what happens in the AM.

Just curious as to what others may think, if this is a sign of impending failure of the dreaded "encoder motor" assembly, or if there is something else I should be looking towards. Snow will be flying here soon, and I'd rather not be doing doughnuts during the first storm.

I have a 2000 bravada and when I first got it everything was great. Then one day the awd light came on and took it back to the dealership and he put it in the shop. He had the awd replace before I bought it. Come to find out it was a bad awd motor. So I am pretty sure that is what wrong with yours.

You are new here and on your no 2 post.
So a little freindly info. Check the date on post before replying and let the old dead post rest in peace. This one is over 5 mo. old and when you reply AF sends everybody here a e mail that you have replied and that WAKES EVERYBODY UP AGAIN.. :grinyes: :lol:
MT

Well ill be glad to wake this on up again, i recently bought a 2000 Bravada with 44K miles and for the first few weeks all was great and man was i happy with the deal i got(6800) plus TTL. anywasy it has recently started the shuddering thing and the front tires skipped on low speed turn in and what not, and i read all about the fluid change and was going to do that this next week, but just read about pulling the ATC fuse, and man im more than happy with the way she drives now, just like they should have built them in the fist place RWD.

But unlike the 99's my Service AWD light had never came on yet, but with the fuse removed its on now, so i guess i can live with that, so much smoother on accerleration and has much more pick up than before, im hoping for a decent MPG increase as well.

Here in Houston Texas we dont need the AWD so i will probably just leave mine this way, until i do an L31 350 swap next year. Which will have a 4L80E 2WD trans installed behind it.

Anywasy if anybody knows how i can get the light to go out, without taking the guage cluster apart and puting black tape in there, let me know.

Thanks again for the info this forum has been a tramendious help.

Congrats on your recent purchase and successful AWD modification.
How 'bout putting a piece of black tape on the dash "lense" in front of the AWD light?
I agree that changing the transfer case fluid is necessary and just plain good maintenance for when you do need to call on it.