4wd issues :/

wurthit4660

New member
New to the Gmc world so go easy on me... just picked up an 02' envoy sle, when I go to put it in 4wd low, high, or AWD I can hear what seems to be it engaging, however the service 4wd light comes on. Also when in one of the
4wd positions the light blinks (not sure if that is the norm or an indicator of something wrong). when I had it in 4wd low only my back tires spun in really muddy conditions. When I turn the vehicle off the service 4wd light goes off and stays off when the vehicle is re-started. service light only coming on when I attempt to use any of the 4wd options.

So is this a sign that I need a new 4wd transfer shift motor? or is it a different problem? Could use some help on this one thanks in advance....
 

Molson02536

New member
New to the Gmc world so go easy on me... just picked up an 02' envoy sle, when I go to put it in 4wd low, high, or AWD I can hear what seems to be it engaging, however the service 4wd light comes on. Also when in one of the
4wd positions the light blinks (not sure if that is the norm or an indicator of something wrong). when I had it in 4wd low only my back tires spun in really muddy conditions. When I turn the vehicle off the service 4wd light goes off and stays off when the vehicle is re-started. service light only coming on when I attempt to use any of the 4wd options.

So is this a sign that I need a new 4wd transfer shift motor? or is it a different problem? Could use some help on this one thanks in advance....
Good chance the front axle discontent has gone bad. There common to go bad and costly to replace. If your lucky, it may just be the wire harness that has gone bad and will need to be replaced or fixed.

The front axle discontent is located on the passenger side. If your luck, it may just be a bad actuator witch is located on the front axle discontent it self. Check to see if there are any damaged wires or the actuator is damaged it self. But as mentioned, in most case your going to have a bad axle discontent.

Keep us posted and start with the simple and check your 4wd fuses to mkae sure there still good, under the hood and the rear seat on the driver's side.

Molson02536:cool:
 

wurthit4660

New member
Good chance the front axle discontent has gone bad. There common to go bad and costly to replace. If your lucky, it may just be the wire harness that has gone bad and will need to be replaced or fixed.

The front axle discontent is located on the passenger side. If your luck, it may just be a bad actuator witch is located on the front axle discontent it self. Check to see if there are any damaged wires or the actuator is damaged it self. But as mentioned, in most case your going to have a bad axle discontent.

Keep us posted and start with the simple and check your 4wd fuses to mkae sure there still good, under the hood and the rear seat on the driver's side.

Molson02536:cool:
For sure will check the fuses, then move onto the actuator. Is there a certain way I can tell if it is working/not working? Looks easy to change out do you undo it and see if it's functioning that way or what? Thanks Molson for the info :)
 

blademan1972

New member
Just went through this !

I just went through this with my wifes 07 envoy if you change the front actuator or the trasfercase motor be sure to go to the GMC dealership to get those 2 parts found out the expensive way that for some reason the envoy does not work well with after market parts I bought both of those parts at Napa and then started to have more problems than before i changed them apparently the 4x4 computer has problems communicating with after market acuators but since they are electrical parts once u install them you cant take them back so not only did i have to shell out almost $700.00 for the OEM parts at dealership but had to eat the cost of the Napa ones because they could not be returned the after market parts causes a feedback in the 4x4 system and turns on the service 4x4 light and puts the 4x4 system in limp mode witch is 4 Low and every thing stays engaged and wont let the truck go faster than about 8mph the only thing that will get the envoy out of limp mode is to pull the 4x4 fuse under the hood !
 

blademan1972

New member
the front actuator makes a distinctive loud buzz then it activates if it doesn't make any noise at all its not working ! trust me I have been fighting with my envoy for over a year and have learned a lot put OEM parts in it and havent had a problem in 3 months !
 
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