03 Z71 4WD Service Message

The other day I started up my truck and I noticed that the message center was displaying "Service 4WD". I then noticed that the 2WD light was off on the push button. I later removed the fuse for the 4WD and it checked out good. I put the fuse back in and started the truck. The message did not return and the light on the 2WD was on. Should I take it in to, get checked out anyway or wait? I tried all modes (4WH, 4WL, 2WD) and they work.

Thanks,
Dean

Get it checked it wont hurt and its free under warranty

I live in alaska, its really fricking COLD here and sometimes the sensors in the 4x4 transfer case dont send properly (the respose I got when i asked why mine did what yours did) So in the winter i have to pull that fuse and put it back in alot. The only time it blew was when it was -40 and i went from 4 high to 4 low. But simple fix, also sometimes the selector box with the push botton selectors just simple goes out. That is common, I had thought it might have been the cause before i found it to be the sensor in the 4x4 transfer case. There are alot of threads on this prob, but anyway its probubly cool. And if its under warrenty then hey why not take it in right but i wont pay 65bucks for the dealership to tell me shit anymore.

Had the exact same thing happen to my 01 Silverado. Dealer replaced the switches on the dash under warranty (it's one module) and problem was solved.

Good luck.

I had this happen to my 2000 4x4. Don't wait to get it checked out. I was told by the sevice dept. that it was trying to switch between 2 and 4 wheel drive while I was traveling down the road. They had to replace the fwd 4x4 solenoid sensor. And of course thishappened after my warranty ran out.

The “Service 4WD” error is a common problem and there is TSB that covers it as follows:

“TSB #03-04-21-001C - (06/24/2003)
4WD Switch Indicator Lights Flashing, 4WD Inoperative, DTCs C0327, P0836, P0500 (Replace Encoder Motor Sensor, Reprogram TCCM, Inspect Front Drive Axle Engagement Sleeve for Damage/Repair if Necessary”

Complete TSB details (http://dieselplace.com/forum/forum_posts.asp?TID=277&KW=service+4wd)

The owner's manual says it's OK if the DIC message goes away after a shutdown and restart. If it keeps coming back you should insist that they (the dealer) fix it.

I took my 03 2500HD in for the "Service 4WD" problem when the truck was a year old with 18kmi. Prior to this I had experienced 2-3 "Service 4WD" messages and each time the message didn't return after a shutdown and re-start. Per the owners manual this is "normal". However, at one point the problem did not away. I had taken a 5-hour trip and when I arrived at my destination I had the "Service 4WD" message. This time the message would not go away after a shutdown & restart, but it would clear by pressing one of the DIC info buttons on the steering wheel. The message continued to come on and the 2W, 4WH, 4WL and neutral indicator lights were also coming on randomly. Seeing the 4WL light come on when I started up was not a good feeling… The dealer found three codes and said the encoder motor needed to be replaced. They had to order the part and wanted to keep the truck because they said it may get stuck in 4WL/H but I asked them to just remove the fuse so I could use the truck until the part came in. A few days later the dealer installed a new encoder motor and re-programmed the TCCM. The service writer told me that in spite of what the owners manual says, they always repair the problem as soon as even one "service 4WD" message shows up. He also said they always replace the whole encoder motor assy, not repair it. He said they had one customer with a truck stuck in 4WL that drove it (in 4WL) on the highway and burned out the transfer case.
:smile:

it's the switch in the dash. it takes about 5 minutes to replace

Change the swith in the dash and your problem wiil disappear. I had to do it to mine after taking it in to GM 3 times and the problem kept repeating itself. Then somebody told me to just have the switch changed out.

it's the switch in the dash. it takes about 5 minutes to replace.........exactly which switch are you refering too. 2wd, 4wd hi,4wd lo, auto 4x4..I have a 99 z71 & am tired of the light comin on .It does go away when i restart, but usually comes back...thxs

The other day I started up my truck and I noticed that the message center was displaying "Service 4WD". I then noticed that the 2WD light was off on the push button. I later removed the fuse for the 4WD and it checked out good. I put the fuse back in and started the truck. The message did not return and the light on the 2WD was on. Should I take it in to, get checked out anyway or wait? I tried all modes (4WH, 4WL, 2WD) and they work.

Thanks,
Dean I had the same problem on my 03 the problem was the switches they put new switches in fixed it they said contacts get dirty cause it to throw that message service 4WD

I have the same symptoms, but the puzzling issue is that the "Service 4WD" light comes on after removing the switch entirely. I was actually on the way to the dealership to retrieve the new switch - when the light came on.

Is it possible that it's still the switch?

I have a 03 Avalanche with the red Nuetral light on, can't change anything, but drives ok. After driving for awhile eveything goes back to normal with 2 wheel indicator on and can change to 4 wheel. Any thoughts? Thanks Brian