4wd trouble on '01 w/ 233 transfer case

I have an 01 ZR2 with the three button 4wd switch, (233 transfer case). One day when I pushed to 4hi button, nothing happened. I put it in neutral and engaged 4lo just fine. Sometimes it will engage 4hi when in neutral and other times it won't. Sometimes no lights will come on the push buttons and sometimes both 4wd lights will come on when I engage 4lo. I'm really confused and have no idea when it comes to 4wd systems.

I jumped pin 13 to pin 4 and got trouble code #2. Upon checking this forum and others, I found that #2 is an encoder motor problem.

Where is the encoder motor located and does it have anything to do with vacuum?

I am going to remove the TCCM fuse and let it sit that way to see if the problem will clear up. I will post again to advise if that does anything to help. Any suggestions would be appreciated, Thanks!

FYI: Pulling the fuse didn't help

i can't diagnose your problem, as i am having some issues with my 4wd, but assuming it really is the motor here is how you change it:

if the '01 is the same as my '97, the encoder motor is on the x-fer case. the haynes manual has a good description of replacing it. the new motor should be shipped in the 2-hi position, so your vehicle should be in 2Hi. raise up on ramps or jackstands, put into park with parking brake on and chock the wheels. remove the front drive shaft (4 bolts near the front u-joint, then pull shaft forward away from the x-fer case splines) for clearance. there is more room if you remove the bash plate too. remove the wiring harness from the motor (bolted down) then remove the three bolts that hold the motor to the x-fer case. pull off the motor. installation is just the opposite. just make sure the new motor shaft is aligned with the keyway on the x-fer case. take pleasure in the fact that you just saved yourself about 500 bucks.

what did you do with the TCCM? how did you check it? how are the pins numbered?

Thanks for the help!

If you have the 233 transfer case (3 push button switch on the dash), you can jump pin #13 to pin #4(ground). Turn the key to on and watch the lights on the switch. If they only come on for a second and do not come back on, there are no codes stored. If there are codes stored in the TCCM, the lights will flash together. If they flash once, then you have a #1 trouble code, twice is the #2 trouble code, etc..

As long as the pins are jumped together the code will continue to flash in 5 or 10 second intervals.

Count the pins from left to right starting at the top to get the pin #. For example, pin #1 will be at the top left.

The code actually says circuit problem.
Check the circuits between encoder motor and TCCM first.
The go threw the function test for that code.
MT

The code actually says circuit problem.
Check the circuits between encoder motor and TCCM first.
The go threw the function test for that code.
MT

thanks. how do you go about checking the circuits between TCCM and motor? is there any published info or directions on this?

what do the vacuum lines under the hood do, aside from connecting to the vac actuator? i know the switch on the x-fer case has 3 vac lines going to it, but not sure where they come from.

thanks

thanks. how do you go about checking the circuits between TCCM and motor? is there any published info or directions on this?

what do the vacuum lines under the hood do, aside from connecting to the vac actuator? i know the switch on the x-fer case has 3 vac lines going to it, but not sure where they come from.

thanks

A all data sub or a good factory repair manual has the flow charts and wiring diagrams for repair and checking it.
Also the vacuum circuit.
Check the wiring and for switch switching.


http://www.alldata.com/products/diy/index.html

MT

thanks. how do you go about checking the circuits between TCCM and motor? is there any published info or directions on this?

what do the vacuum lines under the hood do, aside from connecting to the vac actuator? i know the switch on the x-fer case has 3 vac lines going to it, but not sure where they come from.

thanksswitch on trans fer case?/?just curious can u get a pic up of it plz.

FYI: I disconnected the battery cables for 1/2 hour and touched them together before reconnecting them. That took care of it. I read that resets the TCCM

You're right. After replacing the Transfer Case Encoder motor, disconnect the neg battery terminal for 1/2 hour to reset the TCCM. I now have my 4WD working again. EASY, FREE Fix. Thanks!

http://www.napaonline.com/masterpages/NOLMaster.aspx?PageId=470&LineCode=BK&PartNumber=6002282&Description=Transfer+Case+Motor

Here's a link to the Transfer Case Motor. I got mine for $145 + core charge from NAPA. The Haynes manual has a pretty good description of how to change it out. The switch is a vacuum switch that didn't need replacement as I pointed out above. You can get it from NAPA for under $20.

This is how you change out the Transfer Case (TC) Encoder Motor (EM). I speak from experience that it is MUCH easier if you already have the new part in hand, or at least a ride to the part store to get the new part. You do NOT want to have to button your truck back up to get the new parts. I speak from experience. I just took mine out 4 times this weekend (got a bad replacement part, I hope)!!

If you have the same set-up as I do (1992 4.3L TBI, AT w/ OD & push button 4x4 (w/ New Process 233 TC), you'll need to disconnect the rear of the front driveshaft, you will probably need a pry-bar or something to keep it from spinning on you (make sure you keep a good eye of the U-joints & the needle bearings that are in them), and compress the spline towards the front of the truck. On my S-10, the encoder motor is held on with 3 - 10mm bolts. Take these completely out.

You then need to take loose the nut that holds the front output yoke to the TC. I was able to use a 30mm x 1/2" drive socket I got on loan from Autozone. You can either jam the front yoke from turning with a pry-bar or large wrench by just wedging it in so that the yoke won't spin while you're turning left, OR you can take a 9/16" wrench and slide it up and in between the TC and encoder motor housing until you can get it onto the TC "shift shaft" (it's flat on 2 sides), and then manually spin the shaft until you hear a "clunk", that'll be 4hi, turn it again in the same direction, and it'll be in 4lo (this way is much easier when removing the old unit).

You will need to have a drain pan handy when you slide the front output yoke away from the TC. The yoke completes the seal there. You do NOT need to remove the yoke completely from the splined shaft, but just enough to get the encoder motor (EM) out from behind it. Take a few minutes planning this through in your head, going through the motions, and exactly which hand will be doing what, and you'll only lose a minimum of fluid (Dex/Merk ATF in my NP233), which unless you have a small pump or fluid injector handy, can be difficult (and messy) to replace. Once you have the EM free from behind the yoke, slide the yoke all the way back into the TC to seal it back up. That will keep the fluid from coming out while you get the new EM ready to install.

You can begin to disconnect the electrical connector. There's a 5/16" bolt that passes through one side into the encoder motor side that needs to be completely loosened, and then the connector(s) will just slide apart.

Before you try to install the new EM, PLEASE, MAKE SURE THE TC IS IN 2HI!!!! The installation is a bit trickier, mostly in getting the new EM in place and aligned with the "shift shaft" (it's keyed as well) while you have fluid dripping out all around you, but hang in there. Like I said, work the motions through in your head a few times first. It's easier to put the electrical connector(s) together before you put the EM back in.

The EM bolts need to be "wrist tight". Replace your yoke nut, and make sure it's good and tight Replace the driveshaft, the collar and all bolts you removed earlier. If you lost a lot of TC fluid during this, you need to replace it. There's a large plug on the rear and in the middle of the TC. I was able to use the 30mm x 1/2 drive socket to remove this as well. The fluid level needs to be at the bottom of the "fill hole". So if you fill it and you get leakage, then you're good. Put the plug back in place, and then you can put the plug back in, get off the ground and put your tools away. You're done!!

Good info but this post is very old.
Let old post die/rest in peace.