Changed the four wheel actuator on my 2000 sierra but the servive 4wd light is on at the dash yet

There are actuators on the front axle and the transfer case, check them both.

Light on , DTC- diagnostic trouble code stored in the 4X4 control module . Take's a professional type scan tool to read these code's . Your best bet AAMCO . or dealer .

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.
I have found out that usually the two ground wires that are attached to the frame right under the front of the driver's door is the culprit that causes the 4wd selector switch in the dash to go bad. Chevy had the bright idea of applying the undercoating and/or not cleaning the point of contact of the ground wires before they bolted them to the frame therefore overtime moisture, dirt and corrosion affects the contacts of the threads of the bolts which are the only source of ground the two sets of wires have. There are 2 things you will need to do. First you will need to take the bolts out and use a wire brush to clean down to the metal of the frame as well as the bold threads and ends of the wire attachments and then reattach the ground wires to the frame (time to complete - less than 5 minutes). Second you will need to replace the 4wd selector switch in the dash. You can purchase this online from Amazon (Dorman 901-062 4-wheel drive switch for $31.15 - no tax or shipping and handling). To replace, gently pull the outer trim of the dash out by using just your fingers. You do not need to completely remove it, just pull it out far enough so that you can pull the old switch out of it slot. Then unplug the two plugins located in the back of the switch. Plug them into the new switch and push the switch back into the slot and then push the trim back into place (time to complete - less than 5 minutes). This should take care of your problem. Most often, people make the mistake of just switching out the dash switch and when that does not correct the problem they then replace the more expensive and time consuming actuator motor and location indicator on the transfer case that does not need to be replaced. I should point out that when the Service 4WD light comes on

4X4

On these issue, there are few solved help links for troubleshooting the issue easily.-------

Click the link below: ---

No 4x4 light on dash?

http://repairhelpcenter.blogspot.com/2011/12/no-4x4-light-on-dash.html

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4X4 Truck makes roaring noise in the front end?

http://schematicsdiagram.blogspot.com/2012/01/4x4-truck-makes-roaring-noise-in-front.html

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Car will not go into 4WD high or 4WD low?

http://schematicsdiagram.blogspot.com/2011/12/car-will-not-go-into-4wd-high-or-4wd.html

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No 4x4 light on dash?

http://repairhelpcenter.blogspot.com/2011/12/no-4x4-light-on-dash.html

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4 wheel drive system will not disengage?

http://technoanswers.blogspot.com/2012/01/4-wheel-drive-system-will-not-disengage.html

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4WD light is flashing and beeping? NO 4WD high?

http://schematicsdiagram.blogspot.in/2012/02/4wd-light-is-flashing-and-beeping-no.html

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2002 Jeep Wrangler: 4WD Idiot Light is ON?

http://technoanswers.blogspot.in/2012/06/2002-jeep-wrangler-4wd-idiot-light-is.html

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Traction control switch will not engage on 4WD High or Low

http://whoisbyme.blogspot.com/2012/10/traction-control-switch-will-not-engage.html

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4WD light flashing and 4WD will engage after few minutes

http://repairhelpcenter.blogspot.com/2012/10/4wd-light-flashing-and-4wd-will-engage.html

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2008 Toyota Tundra: 4x4 Wheel Drive Light is Flashing?

http://technoanswers.blogspot.in/2012/05/2008-toyota-tundra-4x4-wheel-drive.html

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4x4 front differential will not engage the axle on ford?

http://technoanswers.blogspot.in/2012/02/4x4-front-differential-will-not-engage.html

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4x4 will not engage on Ford F150?

http://technoanswers.blogspot.in/2012/02/4x4-will-not-engage-on-ford-f150.html

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Dodge Ram 4x4 light keeps flashing

4X4 LOW LIGHT IS FLASHING ON DASH

http://technoanswers.blogspot.in/2012/09/dodge-ram-4x4-light-keeps-flashing.html

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Ford 4x4 front wheels will not engage?

http://technoanswers.blogspot.in/2012/02/ford-4x4-front-wheels-will-not-engage.html

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These details will help.

Thanks.

the actuator on the diff might be stuck. I had a 97 sub and it felt funny when turning hard but turns out i had it in four high. make shure your in 2 high and change the diff lock selenoid

you may have to replace your trasfer case control module its right under dash driver side easy to access mine just went out it was throwing c0359 code 4 low cirut and service four wheel drive would come on dash although the 4wd works great it just throws the code.

could be your front actuator or your actuator motor on the transfer case.

try reversing six to eight feet after shifting into 4WD. PLEASE RATE MY ANSWER.

Have you reset the computer?
If not,you need to diconnect the battery for a few minutes.

Please rate this solution.

For a temporary fix so the car can drive, remove the fuse for the four wheel drive. it won't actuate the four wheel. The car is always in 2wheel drive. the fuse is located under the hood, the very right side of the of the fuse box, the third fuse up from the bottom. This can be checked in the owners manual. When I need four wheel dr I place the fuse back in. I haven't fixed the problem yet but can drive it 2wheel on the road. think it is the control module for the four wheel dr located under the dash board behind the glove box. Dealer part for $450, I would rather install and remove a 10cent fuse