How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 15133
Experience:  GM Grand Master Technician 2007. 14 years experience.
10949255
Type Your Chevy Question Here...
GM Tech (Cam) is online now
A new question is answered every 9 seconds

Chevrolet Suburban 1500: I replaced a nqh transfer case with

Customer Question

I replaced a nqh transfer case with one from a junkyard that is known good and after installing it I put the truck in 4wd to see if the problem was still there but once I did I got dtc c0387 and it will not come out of 4hi. Any ideas?
Submitted: 1 year ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 1 year ago.
hi there, I am Cam. Sorry about the long delay in getting to your question. Can you tell me why you changed out the transfer case to start with while I check up on that code?
Customer: replied 1 year ago.

The chain was jumping in the old case when in 4wd and hard acceleration. That's now fixed but now my new problem which seems electrical. I don't not have a tech2 but I have a snap on scanner but since the dtc is set I cannot do a relearn on the encoder motor. I feel like that's all I need but I cannot get it back into 2wd.

Expert:  GM Tech (Cam) replied 1 year ago.
Do you have the info on that code?
Customer: replied 1 year ago.
Yes I know the code is for failure to shift. And I have the run down of stuff to trouble shoot from my snap on scanner but nothing works I feel like I am missing something on installing the new case programming wise because none of this was a problem before the new case was installed.
Expert:  GM Tech (Cam) replied 1 year ago.
Ok, lets try something. Lets do a reset. Take the battery cables off the battery, hold the ends together for 10 seconds then attach them to the battery and see what happens. This will reset the whole vehicle.If you have 2 batteries, then remove both and touch only one set. Then plug it in and try to shift. If it does not then take the motor off your old case and plug it into the new case and try that.
Customer: replied 1 year ago.
I've tried it with no luck.
Expert:  GM Tech (Cam) replied 1 year ago.
Ok, did you do any of the testing in the document?
Customer: replied 1 year ago.
The document you sent was for fuel rail pressure...?
Expert:  GM Tech (Cam) replied 1 year ago.
Oh, sorry that is strange. here is the proper one.
Customer: replied 1 year ago.
I will need to try these tests later today or tomorrow I am out of the shop now. I will let you know how it goes and if I have any luck. Thanks for the response.
Expert:  GM Tech (Cam) replied 1 year ago.
Sounds good. Please bookmark this page so you can easily navigate back to it so we can continue the discussion. This is done by pressing (CTRL D on PC and CMD D on Mac). You can reply at any time for follow up information regarding this issue, even after you rate the site and I will reply.
Customer: replied 1 year ago.
Everything checks out you can turn the motor when removed from the tcase and hear it lock and unlock but it's not letting me clear the code and unlock the tcase from 4hi when installed.
Expert:  GM Tech (Cam) replied 1 year ago.
Can you turn the shaft of the replacement transfer case?
Customer: replied 1 year ago.
Yes and I can switch it in and out of 4wd with the controls on the scanner.
Expert:  GM Tech (Cam) replied 1 year ago.
If you disconnect the sensor, does it set codes that you can read?