My fourwheel drive will not work tied a new swicht still nothing is there a way to test the four wheel drive computer to see if its working or test the actuwater or now if its just sinsers

There could be a few possible causes for your 2002 Chevrolet Tahoe not going into four-wheel drive when you engage the system. Some common issues include:

The four-wheel drive system may not be properly engaged. Make sure that the four-wheel drive switch is in the correct position and that you are following the proper procedure for engaging the system.

The four-wheel drive system may be mechanically damaged. This could be caused by a problem with the transfer case, the drive axles, or other components of the system.

There may be a problem with the four-wheel drive system's control module or other electrical components.

There may be a problem with the four-wheel drive system's vacuum lines or other mechanical components.

To troubleshoot the issue, you can try the following steps:

Check the four-wheel drive switch and make sure it is in the correct position.

Check the four-wheel drive system's control module and make sure it is functioning properly.

Check the four-wheel drive system's vacuum lines and make sure they are not damaged or disconnected.

If the issue persists, it may be necessary to have the vehicle inspected by a qualified mechanic.

If you are not comfortable performing these steps, or if the issue persists after trying these troubleshooting steps, it may be a good idea to contact a mechanic or a Chevrolet dealership for further assistance.

the four wheel drive is controlled by a electric actuator that is located on the transfere case

Easy fix., Unhook the negetive batt terminal for 30 seconds and hook back up. 99 % of the time this will fix the problem

the buttons to the right are the ones to put it in fourwheele drive the top is for four high and the botttom is for four low

Run hot wire from battery stright to bat. side of coil and see what happens.

check fuses should b a 4wd fuse refrence your owners manual. if not problem try removing batt connectors pos and neg. resetting computer. sometimes transfercase gets jammed.

i had a problem with the four by four light coming on all the time. I would shut the vehicle off and the warning went away. Recently I had the bearings and tie rods changed on the two front wheels, and now the four by four light does not come on anymore. Not sure if they are related, but it seems to have fixed the warning light. You might want to get your alignment checked and if it keeps going out, then it may be loose tie rods. Hope this helps.

tap on the 4wd motor on the transfer case while someone is pushing the button, if engages you need a new motor

the four wheel drive uses vacuum hub locks. there is a vacuum solenoid on the passenger firewall in front of the battery box. sounds like you need a updated solenoid and possibly one or both hub locks. what happens is the old style solenoid vent allows water to get in and the hub locks freeze or stop working because of the water. the new style has a cover over the vent to prevent water from getting in.

if it is a 4x4 the switches are on the dash board in frot of you, in order
2 HI , 4 HI ,4 LO