"Service 4WD"

**ElQueso** · 06-10-2009, 03:34 PM

Hi all,

My 2005 suburban started giving me a "Service 4WD" message about two months after I bought it. I took it in, they told me that it is a bad sensor, and want 500 bucks to replace it. So much for my extended warranty, two months in and my only problem can't be warranty work.

Can anyone tell me if this sensor change is something a guy with above average mechanical skills can tackle?

Thanks!

**99monguse** · 06-10-2009, 03:49 PM

Why won't the extended warranty cover it?

**Jimmiee** · 06-10-2009, 03:54 PM

I would not believe it's a sensor. Get it scanned an report the code stored in memory. Then and only then will you know where the problem is.

**BurtsBurb** · 06-12-2009, 08:28 AM

You may want to get a second opinion. That light came on on my Suburban in 2007. I took it to an independent shop (non-dealer). They replaced the 4X4 dash switch, which took care of the problem. Cost $169.

**Jimmiee** · 06-12-2009, 09:11 AM

Originally Posted by BurtsBurb

You may want to get a second opinion. That light came on on my Suburban in 2007. I took it to an independent shop (non-dealer). They replaced the 4X4 dash switch, which took care of the problem. Cost $169.

Exactly! It may need a switch or a sensor or it may have a bad electrical connection. The trouble code stored in memory will tell him where the problem is.

**Bikeman** · 06-12-2009, 09:48 AM

check the atc fuse in the uhfb, could be open.

I had a intermitten "service 4wd" in my 01 burb, I can't remember what dtc it was setting for the life of me but after checking the hi-lo motor and related wiring it ended up needing the atc module. Cost was around $300 I installed my self.

Did the shop give you a diagnostic trouble code on your paperwork?

**Springthing** · 06-12-2009, 11:15 AM

I vote for a second opinion as well. It seems the most common problems for the S4WD light is the switch box (the push button controller) or the transfer case's actuator.

I can't answer your question directly about whether or not you would be able to do the sensor yourself though I can tell you that the above two are easily enough done by the shadetree mechanic.

I replaced my switches myself. Under $20 and it was done.

Good luck,