You are here:

4 Wheel Drive/SUVs/4WD service light on 2004 suburban

Advertisement

Expert: - 10/6/2005


Question
The service 4WD light came on in my 2004 Chevy Suburban, the vehicle will not go into 4WD when the light in on, the dealer told me that it will generate a code in  the computer to let them know what if anything needs to be repaired.  When I took the vehicle in to have it checked out they told me there was nothing in the computer to indicate a problem.  Is this scenario correct or do I have a dealer that does'nt know what they are talking about?

Answer
Steve,

The first thing that I would do, is to purchase a Chilton's, or Hayne's repair manual for your Suburban.  That way, you can check out some of the basics yourself.  

I have heard of some of the newer transmissions, and transfer cases having problems when there is a bad ground.  This is due to most of the shifting done electronically, and the sensors not receiving the proper voltage.

If there is a computer, or sensor error, then the dealer's scan should have shown a fault code, especially if the service 4WD light is on.  

If the manual doesn't work out for you, I would take the Suburban to another reputable shop, (possibly one that specializes in transmissions and 4 wheel drives) and have it scanned again.

A knowledgeable dealer would have a complete shop manual which should give them a list of errors that would cause this light to come on.

Carl

4 Wheel Drive/SUVs

All Answers

Answers by Expert:

Ask Experts

Volunteer

Carl Brandt

Expertise

Will discuss suspensions, lifts, lockers along with tire suggestions. Trail ratings and possible requirements needed for specific type of trails. Safety equipment and what you should carry with you. Certified off-road instructor. I am not a mechanic, and 4-Wheeling is a hobby, so if I can't answer a technical question it is due to my mechanical knowledge being related to vehicles that I have owned, or have worked on. I do not have manuals on all vehicles.

Experience

40 plus years of 4 wheeling in a variety of vehicles. At the present time, my major off-road rig is a 94 Jeep Wrangler with a spring over and a 1 1/2" suspension lift. This gives me a total lift of 7" or so. I have lockers front and rear. I have removed the track bars, and sway bar for maximum articulation. I am running a stock 2.5 ltr 4 cylinder with a Jacobs ignition along with a cold air high flow filter. It has 4.56:1 gears with a Dodge NV4500 transmission along with a 3.8:1 Atlas II transfer case. This gives me a final ratio of 105:1 in low gear/low range. Other vehicles I own, are a 96 Ford F-250 with a 6" lift, posi rear end, 36" Hummer tires, 5 speed with a fuel injected 460 ci engine, an 87 Samurai with an 8" lift, Ford 9" rear end with a spool, Chevy Dana 44 front end with an electric locker, 5.88 gears, 16% reduction in high range and a 6.5:1 low range with 35" Baja Claws, and a stock 2003 Grand Cherokee Overland. Trails I have run are the Rubicon (10 times), Dusey Ershim, Fordyce Creek trail, McGrew trail, several trails in Moab, Utah along with local monthly runs.

Organizations
Lost Coast 4x4's Cal 4-Wheel Corva UFWDA Blue Ribbon Coalition

Education/Credentials
Certified off-road instructor - Certificates in engineering/electronics

©2012 About.com, a part of The New York Times Company. All rights reserved.