4 wheel drive problem
- Thread starter Roger L
- Start date
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swathdiver
Full Access Member
Welcome Roger. Do you have a access to a scan tool that can pull these kinds of codes? It might just be the switch but codes will point you into the right direction for solving this.
I had it scanned but the scanner wouldn't nail it down, today the red neutral light came on while I was driving
swathdiver
Full Access Member
They found no codes? That is odd, there should be codes, even a UXXX code if the transfer case module for example stopped communicating. If you want to start shotgunning it, start with the control module there on the dash. Do some searches on here from now back to 2017, I know we've been over this one before but my memory is not so good to remember the details.
Bet it's the dash switch or the encoder motor on the TC. Codes might help, @Roger L.
Which TC? NP246 (see round metal tag on the TC)?
Which TC? NP246 (see round metal tag on the TC)?
The new switch lasted two weeks, put in another new one, it lasted two weeks. Napa called the companies tech line and they said the control module is probably feeding back to the switch and burning it out? Anybody ever hear of such a thing?
@Roger L, post a pic of the dash switch. Also do you know which transfer case you have? (see post #5)
Look in the glovebox for the RPO codes. They're on a sticker and there will be 30 or 40 of them. You should have an NP1 or NP8 there, or something similar. That code will tell which TC.
I found NP5 and NP8
NVG 246 TC, then.
Easy thing to check first is the ground connection that is under the driver's side front seat, just aft of the wheel well. There should be two ground bolts there and those need to be in good shape. Recommend cleaning those two connections first.
To get codes you need a Tech 2 or an advanced reader that goes beyond engine codes. Most of your Advance Autos aren't going to have those higher level scan tools, so you may have to look around for one.
The automatic transfer case control module (ATCM) behind the dash should be supplying 5v DC to the dash switch. If you want to check that the Tech 2 can read it or you can pull the dash switch out and measure it with a voltmeter at the harness connector. (A wonky ground as mentioned in my first sentence can cause voltage issues here.) If you need the pinout let me know and I'll see if I can find and post it.
I know that you have bad switches but those can be ohmed out. Not that it will do you much good if you've already determined that they're bad. See the third page of this PDF for the values, but also note that the full article is for a different encoder motor system and references 8v, not 5v. Your system should be 5v. http://www.atraonline.com/gears/2006/2006-08/2006_08_08.pdf
EDIT: measurement procedure here, starting at about 2:10 into it.
You can also ohm out the encoder motor pins; I should have those values from Dorman and would be happy to share them if you're interested. Just let me know how far you want to dive into this.
Easy thing to check first is the ground connection that is under the driver's side front seat, just aft of the wheel well. There should be two ground bolts there and those need to be in good shape. Recommend cleaning those two connections first.
To get codes you need a Tech 2 or an advanced reader that goes beyond engine codes. Most of your Advance Autos aren't going to have those higher level scan tools, so you may have to look around for one.
The automatic transfer case control module (ATCM) behind the dash should be supplying 5v DC to the dash switch. If you want to check that the Tech 2 can read it or you can pull the dash switch out and measure it with a voltmeter at the harness connector. (A wonky ground as mentioned in my first sentence can cause voltage issues here.) If you need the pinout let me know and I'll see if I can find and post it.
I know that you have bad switches but those can be ohmed out. Not that it will do you much good if you've already determined that they're bad. See the third page of this PDF for the values, but also note that the full article is for a different encoder motor system and references 8v, not 5v. Your system should be 5v. http://www.atraonline.com/gears/2006/2006-08/2006_08_08.pdf
EDIT: measurement procedure here, starting at about 2:10 into it.
You can also ohm out the encoder motor pins; I should have those values from Dorman and would be happy to share them if you're interested. Just let me know how far you want to dive into this.
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I appreciate the help, I'm a former mechanic with health issues and can't get around like I used to. I'll try to check the ground first, then check the voltage at the switch. Thanks
Sean Collins
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I've heard the grounds under the driver side on frame right behind the tire cam break. The ground for the 4WD motor is there. See if anything is going on there
Sean Collins
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Oops lol sorry for the repeat haha
I finally got the grounds cleaned up and tested the switch. I'm getting 5 volts to it and ohms test checked out good, still no lights at the switch and it still does nothing
Probably a bad switch still, buy a oem or get one from a different supplier, if I remember correctly a new oem online is about $65.00 the problem is common with these switches they have a ghost in the machine, sometimes you can kind of make it work by holding down the selection button you want while you start the truck keep holding it in a few seconds then release.
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