Why does the 4wd service light stay on - 2002 GMC Envoy

this could be an over heating warning light and 30 minuets is time for it to cool off if the light stays off now there is nothing to worry about

Read the users manual, it should go off after the engine starts, if it stays on there is a problem, you will have to take the car to the service to check out.

this is most commonly a electrical problem, does the speedometer read out correctly? if not it may be depending on if this is a Autotrak model, one f the two speeed sensors, or the acuator on the front diff, put the truck in 4wd, check the front dirveline to make sure it is engaing, if not your problem is in the t-case, if it does then move to the tires, if they are not engaged you have a problem with the actuator.

in most cases i have found the actuall 2wd 4wd switch to be the problem if you find that the switch is acting slow or you need to select the gear a few times before it shifts, then replace it these are very faulty

4x4 shift module in the dash is most likely problem

With scan tool reset the ecu, if light still on check for 4wd opertation if its ok, take the car to a specialize technitian for diagniostics.

sometimes a fuse might be going bad.....thus leading to lights turning on...i wouldnt pay too muc attention to the light unless it comes on more frequently or stays on. if so definitly get it checked out.

Have you ever had the 4X4 transfer case serviced with new fluid? If not try that first.

Don't mess with it!!!!! Your new vehicle has a warranty. Get back to the dealer ASAP and don't take anything apart. You paid good money .... let them tear their hair out.....that's what they get paid for!!!!

If you had the switch and encoder motor replaced 5 months ago, then you have warranty. You need to return to the dealer and have them pull codes to see if it is the C0327 again. Some of these trucks also had grounding issues for the 4wd module. If it is the same c0327 code stay on them and make them confirm their original diagnosis.

From someone that has had a 2000 Blazer for 6 years now I would say return the vehicle if you can and run the other way. Blazers are VERY poor in consumer reports and I average spending almost 1000 every 2-3 months. Oil cooler lines leaking, Idler Arm, Ball Joints and Bearings (felt like I was on ice in summer), Fuel pump. What a headache. I will never buy another GM.