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Discussion Starter #1
Would like to say hello to everyone! This my first time here. I own a 02 bravada and the front wheels do not engage when the back wheels spin. There are no lights on the dash. Encoder motor?
 

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Discussion Starter #3
Thanks!:woot: Do not have a selector switch on Bravavda. Do I check for power at the encoder motor?
 

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2009 chevy
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Not easy to diagnose from here, but it could be one of a number of things.
As you said, u don't have a selector switch, but you do have most of parts that the 4 x 4 trucks have.

Power is sent forward when slip is detected at the rear. You have a sensor that monitors the rpm of each drive-shaft. The transfer case control module (TCCM) monitors these sensors, when a difference is detected, the TCCM commands the encoder motor to engage the front drive-shaft.
That's how the electronics operate, but you could have a mechanical problem.
Your tx case may be sending power forward, but a bad front diff could be keeping it from getting to the wheels.
I like to check the mechanical 1st. Get it up on jack stands and see if turning the front drive-shaft will spin the wheels. If that's good, we can hit the electronics. Try it and let us know.
 

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Discussion Starter #5
Got the beast up in the air. All mechanical working good. Checked both speed sensors while in gear with ohm meter. Both checked ok. Unpluged encoder motor and ran a seperate power wire to it and it spun both ways.Plugged it back in now AWD seems to working. Could it have been a dead spot in the motor or the sensor? Did notice some binding in steering when I was making a sharp turn out of the driveway. I,m thinking of just replacing the encoder motor.
:thx What do you think?
 
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