service awd light

[gary tomporowski]

I have a 99 Bravada, this past summer my awd light started to come on, stay on a few days then go off. It still does it, unfortunetly the snow is here, when the service awd light is on I'm only in 2 wd, when it's not on it's locked in 4wd! It's been 2 weeks now the light is still on and were getting more lake effect snow tonight. Ive' read the other posts about the awd light problems but none of them sound like my problem. Can anyone help me out?

[MT-2500]

Well read your owners manual.
Most of them require special fluid and service/fluid change ever so often.
Get it in to a dealer or qualified repair shop and have it serviced or you may be buying a new transfer case.
Why did you not get it done when the light came on last summer?
MT

[boldsmobile]

there should be an error code. it could be one of the sensors it needs to measure shaft speed to know if there is wheel slip.

also could be the motor on the transfer case that does the 4wd engagement. if when you turn the key you hear a click, click , click in the passeneger kick panel it could very well be your engage motor. if its seized the 4wd computer is trying to engage it during start up diags and the clicking sound could be the solenoids failing to engage the motor. that motor is an easy change and costs somewhere about 175.

good luck

[gary tomporowski]

Originally Posted by boldsmobile

there should be an error code. it could be one of the sensors it needs to measure shaft speed to know if there is wheel slip.

also could be the motor on the transfer case that does the 4wd engagement. if when you turn the key you hear a click, click , click in the passeneger kick panel it could very well be your engage motor. if its seized the 4wd computer is trying to engage it during start up diags and the clicking sound could be the solenoids failing to engage the motor. that motor is an easy change and costs somewhere about 175.

good luck

Intresting, Ive had a clicking for a while, its coming from my relay switch behind the glove box which I replaced , but still clicks when the truck is running . I read a prior post about the clicking noise and they said its from a bad relay switch thats located in the stearing colume. Where exactly is the motor your talking about, it seems to stop clicking when I touch the break pedal. I havent changed my fluids yet, thats next on my list as soon as get some more cash. I did locate my fuse marked ATC, pulled it out, its good, put it back in and the AWD light went off and was back in 4WD, thank god, cause it snowed that night

[boldsmobile]

The clicking i had came from the computer that controls the 4wd. This is not the main PCM. It is located under the passenger side kick panel. Its a silver box, maybe 6" x 6" in size with two plugs going into in.

The motor it drives is on the transfer case on the drivers side. You need to pull a driveshaft to get to it. It has about 3-4 bolts holding it on. I think there is one plug going to it.

When i took my motor down and put a striaght 12v to it, it would not move. My guess is that the clicking was coming from inside the truck because the computer was doing it start up diag and the motor would not move as it was frozen. Its less than an hour to change.

Dont know for sure if thats your problem too but it fixed mine. I also had a bad sensor but the computer should report that.

The motor acts like a shift lever. When the rear wheels slip, the motor turns and enagages 4wd. As the slipping stops the motor disengages.

good luck