02 z71 4x4 problems continue. New switch, new encoder, same problem.

[Dino009]

Thanks man ! Ill try that tomorrow. Hopefully it works.

 

[Dino009]

Thanks for your help guys but it's a no go. So gonna take it in and get it ready programmed.

 

[Dino009]

I got the TCCM re programmed. I can switch into the different selections and I can hear the motor make the switching noise, but the 4x4 still does not kick on. There's no messages or anything. We got bucnha snow and it doesn't have any traction.

 

[Fless]

If the front diff isn't engaging then there are two things to check.

The first is the double ground near the frame rail, directly behind the front left wheel (terrible place to put grounds), right underneath where the driver's left foot would go. There should be three ground wires there on two bolts. One of those is critical to the 4x4 functioning properly. Clean and repaint.

The other thing to check is the front diff actuator. If it's lazy or not not working, the diff won't engage. Could be an actuator problem or a circuit problem that doesn't throw a code.

 

[Dino009]

Thanks again. I'm gonna take it in again next week too much fuckery for me. But I'm really betting it's the actuator. I will check the ground though.

 

[Fless]

You can unscrew the front diff actuator and let it hang from the wiring harness. With the key on "run" hit the 4x4 (not the Auto) button and the actuator should extend within a second or so. Any longer than that, or not at all, the circuit should be tested and verified for full voltage and a good ground. If the circuit checks out change the actuator.

Bench test:

This video shows the ground wire and the actuator test (with a scanner, but you can test it as stated above).

 

[Dino009]

Thanks for the video. I will look into it. I really appreciate your help.

 

[Dino009]

I took it to the shop and looks like I gotta partially rebuild or fully replace front differential. Buncha broken parts. He cpudkbtcone give me an estimate because parts store was closed cuz it's the weekend. Do you guys know how big of a job this is to fix ?

 

[Dino009]

Finally got the total quote to replace it $2700 CAD. Seems expensive but still waiting on other quotes.

 

[S33k3r]

Can you just buy a used replacement? This seems like a rare repair, which means most of the used examples should still be in good shape.