The 4WD transfer case encoder motor position sensor or the selector switch may fail causing the service 4WD message to be displayed. Fault code(s) stored in the transfer case control module will be of assistance in determining the exact fault causing the message to be displayed.
Car Problem Reports
Chevrolet Suburban 2500 4WD Transfer Case Position Sensor/Selector Switch May Fail
Chevrolet Suburban 2500 Problem
Drive Train Affected: 4WD
Average Mileage: 108,569 mi (15,900 mi - 225,000 mi)
Visitor, 2005 Chevrolet Suburban 2500, 4WD, 84,500 mi
Service 4wd digital message appeared on my information center, is intermittent, two wheel drive seems to always work, but can not put it in 4wd when it appears.
Visitor, 2004 Chevrolet Suburban 2500, 4WD, 77,000 mi
Transfer case gear selector not operating properly, replaced and continued to have problems, when I turn on vehicle I never know what drive I'm gonna be in. Sometimes 4low, which is the worst c opti . Try getting to work on the hiway in 4low, why isn't this a recall item, very dangerous.
Visitor, 2005 Chevrolet Suburban 2500, 4WD, 100,000 mi
I can not get my truck to go into 2 wheel drive at all. It switches between 4 high and Low on its own.
Visitor, 2005 Chevrolet Suburban 2500, 4WD, 82,229 mi
Service 4 Wheel Drive Light came on. Took it to the Dealership for diagnostic. Dealer informed me at that time that the Encoder motor had failed. Replaced Encoder Motor back in May, 2008 for $1, 118.00. Recently my service 4 Wheel Drive light came back on. Took in to the dealership on September 2010. There diagnostic disclosed that the encoder motor has failed and the cost of repair would be approx. $800.00. GM need to do a better job at building a better product or they will never be successful in this current market place. This is totally unacceptable.
Visitor, 1999 Chevrolet Suburban 2500, 4WD, 15,900 mi
My indicator light does not work all the time. I am not sure it stays in the correct mode. I don't want to replace the switch if that is not the problem.
Visitor, 2003 Chevrolet Suburban 2500, 4WD, 82,000 mi
can not get 4 wheel high or low to engage 4x4 service lite comes on what sucks is the 4 wheel has only been used three times and it sounds like a lot of owners have had the same issue WHATS UP GENERAL MOTORS
Visitor, 2005 Chevrolet Suburban 2500, 4WD, 82,000 mi
The 4WD button does not work therefore leaving a message on the dashboard LED saying Service 4WD. Its so annoying, I just fixed this problem before winter started. I will never buy another Chevy again!
Visitor, 2005 Chevrolet Suburban 2500, 4WD, 102,000 mi
Service 4-wheel drive warning erratic. Now when snow is 2 feet deep the lights on control panel go out completely. Unaable to to shift into 4 wheel drive. Grrrrr
Visitor, 2005 Chevrolet Suburban 2500, 4WD, 152,000 mi
Second time this has occurred. Dissappointed in the QC on this unit (which is my 6th Surburban)
Visitor, 2004 Chevrolet Suburban 2500, 4WD, 225,000 mi
I had the same intermittent problem with service 4wd. Sometimes I could shut off and restart, then it would shift from 2 to 4. I tried 4 different code readers and none gave me any codes. Finally it would not work at all. I changed the push button no change, changed control module, no change. I removed the shift motor assembly and bench operated it. It would run by powering the black and red wire. I tried to operate the new shift motor and it would not run without powering the brake wires ( pink and white heavy wires.). Opened old shift motor and found 1/2 teaspoon of oil inside lubricating the motor and brake. Change shift motor works great.