[Digger84]

Ok now go to page 8W-31-1
Section called Transmission control system

You will see an entry called
Transfer.case switch listed as 8W31-2 , 15

Then look at those pages
8W-31-2 is non Rubi switch giving ground to cluster

And

8W-31-15 is switch connected to PCM image I already posted




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[Tony T]

You're right, I see it now on Pg 8W-31-15.
It makes sense that the Rubicon is the "Off Road Package" but what confuses me is that on pg 8J - 37 it says "Models that are equipped with the Off-Road Package do not have a hard wired transfer case switch input". The 5 position switch looked like a "hard wired" switch to me.

edit: ok, I see it now, "hard wired" to the console, not through the PCM

 

[Tony T]

Since the 4WD indicator is not coming on & the lockers are not engaging meaning the PCM is apparently not getting the 4WD lo signal I would say there may be a problem in the switch or wiring between the switch & the PCM.

I would suggest you check the resistance at the switch (connector disconnected) in each of the positions then if they are as the FSM shows, go to the PCM & unplug the C-1 connector there & check the resistance between the wires there to see if it is the same as at the switch. That should answer if it is a switch or wiring problem or something else.

Since its a new switch (that could be defective), I start with the wiring to the PCM

 

[RUBI 4 MY MRS]

The Rubicons need more than an on-off switch since it needs to know both 4WD hi/lo for the indicator & 4WD lo for the lockers.

 

[Digger84]

Looks like it is really just a variable resistor like a pot with a slider where resistance varies with plunger extension making length of plunger and how FAR it is screwed in important

Which is why the easiest step one is replace sensor with proper ohm resistor and see if light comes on

Measuring resistance with sensor installed is also fine but measuring resistance of removed sensor is not workable as cannot tell where plunger was along its stroke when installed and 4 hi or 4 low selected


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[Digger84]

It sounds like voodoo but this guy who installed a new OEM sensor then had to do a PCM reset and a cluster self check to make it work after new sensor install

Sounds silly but costs nothing and worth a try

See link

https://www.amazon.com/gp/aw/review/B007NPB57C/R37IHQ5RZT1PJ4/ref=cm_cr_dp_mb_rvw_2?ie=UTF8&cursor=2


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[Tony T]

Just measured the resistance of the old switch, and it was working (checked all positions from fully extended @ 20mm to position 1 @ 10mm (2H)
At 12mm (4H) I got a reading of 671Ω, so while you're correct that placing a 700Ω resistor on the plug is the right step 1, the only way that would light the indicator would be if the shaft in the T-Case that moves the plunger is where the problem is (which is possible).
So, while I agree with you, I think I'll jump to step 2 and trace the wire looking for a break before I make a trip to radio shack to get the resistor.

And thanks again for your help. This has been a frustrating little project (first I couldn't get enough leverage from under the Jeep, so I had to get to it from above by removing the T-Case shifter, which meant a trip for a 1½ socket, then of course I needed a ½" swivel and I only had a ⅜" — which didn't bother me until I found out that the new switch wasn't the problem)

 

[Tony T]

It sounds like voodoo but this guy who installed a new OEM sensor then had to do a PCM reset and a cluster self check to make it work after new sensor install

Sounds silly but costs nothing and worth a try

See link

https://www.amazon.com/gp/aw/review/B007NPB57C/R37IHQ5RZT1PJ4/ref=cm_cr_dp_mb_rvw_2?ie=UTF8&cursor=2

Interesting. Similar as mine ("This happened after I did a clutch install, so I thought that the harness wires were pinched"), except that since I didn't go into 4WD for months before the clutch install, I could not confirm that that clutch install caused the problem.

I'll give that bit of voodoo a try.

 

[Tony T]

It sounds like voodoo but this guy who installed a new OEM sensor then had to do a PCM reset and a cluster self check to make it work after new sensor install

Sounds silly but costs nothing and worth a try

See link: https://www.amazon.com/gp/aw/review/B007NPB57C/R37IHQ5RZT1PJ4/ref=cm_cr_dp_mb_rvw_2?ie=UTF8&cursor=2

Holy Shit!! It worked!!!

How did you even find the answer buried within an Amazon comment!

Thank you, thank you, thank you!
I owe you a beer, hell, I owe you a case!
And let me say Thank You!

:iamhappy:

I'll post the full Amazon Comment you linked here:

Jeep 241OR TCase switch
Customer rating 5.0/5.0
July 17, 2014
Amazon Verified Purchase
1 out of 1 found this helpful

Fitted to my 2003 Rubicon Tcase 241OR RockTrack. You need a 1 1/2" socket on a 3/4" ratchet to get the old one out and the new one in after disconnecting the harness plug on top of the switch sensor. Trickier without body lift (I have one). This happened after I did a clutch install, so I thought that the harness wires were pinched, checked them all , and came to conclusion that the switch bit the dust somehow during the removal and reinstall.

My symptoms were that the 4WD light didn't come on and therefore the lockers didn't engage in LOW range. After installing the new switch, I still didn't get the 4WD light to operate, I did a battery disconnect, no luck, then tried this, quoted from another website :-

1. Disconnect the POSITIVE battery Terminal and touch it to ground for 30 seconds. (This is to discharge the PCM capacitors, which maintain the Adaptive Memory.
2. Reconnect the Battery Cable
3. Turn Ignition Switch to the "ON" position but DO NOT start the engine
4. Turn Headlight "ON"
5. Turn Headlights "OFF"
6. Turn Ignition Key "OFF"
The PCM Adaptive memory has now been flashed, or erased from the PCM.

Still no 4WD light. Soooo.....

I did the dash light test routine (google it, if I remember it's hold the ODO switch and key-on the ignition switch) and then the light came back on after keying off and back on. YMMV.​

 

[Digger84]

Just as an aside looks like off road is what the OR in 241OR stands for so kinda makes since FSM calls it off road

This from JP mag article

"Variations: Shown here are the only two Jeep versions that exist. Shown on the right is the Rock-Trac, which is known as the 241OR (OR stands for off-road). The non-Rubicon model is labeled 241J."

Full TC case article here

http://www.fourwheeler.com/how-to/transmission-drivetrain/154-1201-jp-guide-to-jeep-transfer-cases/

Still not a excuse for FSM diagraming it as a simple open closed switch

I did learn something new about that switch and I am grateful

One last question as you depress the plunger on an uninstalled switch is it a smooth continuous travel or are there detents you can feel

Since same switch is listed for some WJ may pick up one at you pull it just to play around or dissect it and see what is inside



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[Tony T]

One last question as you depress the plunger on an uninstalled switch is it a smooth continuous travel or are there detents you can feel

The plunger is a smooth travel. Need to measure the travel in 2mm increments to determine the position

Since same switch is listed for some WJ may pick up one at you pull it just to play around or dissect it and see what is inside

If you want my old one to take apart, PM me your address.

Thanks again!!
:iamhappy:

 

[RUBI 4 MY MRS]

Good find, Digger! This is going in my file.

 

[Builder]

I’m stuck on this issue. I’ve bought 2 switches, factory Mopar, and then tested the switches which proved to be good. So the switches are OK. I’ve put a paperclip in the plug to complete the circuit, and the 4wd light comes on... so it seems that my wiring is good. When I have the paper clip in and the 4wd light is on, the lockers operate as needed. BUT, when I plug into the switch, nothing works. Wtf!? My plug is good, switch is good, but when they mate they don’t work. This relationship is killing me. Any one here have an idea on what next? And yes, I want to get this working as I’ve set my mind to it. I’ll do the hack after I solve this mystery.

 

[Builder]

The reason I have resurrected this dead post is because it has good info in it. Personally I just have an unsolved mystery. Tried everything already posted here...

 

[RUBI 4 MY MRS]

I’m stuck on this issue. I’ve bought 2 switches, factory Mopar, and then tested the switches which proved to be good. So the switches are OK. I’ve put a paperclip in the plug to complete the circuit, and the 4wd light comes on... so it seems that my wiring is good. When I have the paper clip in and the 4wd light is on, the lockers operate as needed. BUT, when I plug into the switch, nothing works. Wtf!? My plug is good, switch is good, but when they mate they don’t work. This relationship is killing me. Any one here have an idea on what next? And yes, I want to get this working as I’ve set my mind to it. I’ll do the hack after I solve this mystery.

I think putting the paperclip in causes the PCM to think you are in 4WDL. The variable resistance is lowest in 4WDL which would be returning the highest voltage to the PCM. Bypassing it with the p-clip will return max voltage & probably “fooling” the PCM.(?)

The best way to check the switch is to check resistance with it installed & the TC in each of the 4 positions. If it (or both) is off on the readings that will tell you what is going on.

It is very important that the switch be properly installed. It needs to be threaded in the correct amount to maintain the proper plunger position to get the correct resistances. The FSM says there is an O ring which I assume (never had mine out) allows the switch to bottom out against the TC housing so if you use a gasket or are not seating the switch to the housing for some reason that will affect the position/resistance.

 

[Builder]

I agree that jumping the plug with the paperclip tricks the computer since there is no resistance and no switch.

Regardless if the switch is install or not, testing for the proper resistance will be the same. Never measure the reistance of a circuit with a live current flowing through it.

It is easy to push the plunger in and see the 5 positions and the corresponding resistance with each position. The switches passed this test perfectly.

Yes, there is a little o-ring at the base of the threads to seal and keep fluids in. The switch, when installed, has no gasket... It is metal to metal. So the position has to be good. Inside he 241OR case, there is a metal bar that is all the way up in 2H, a little lower in 4H, a little lower in N, and at the lowest in 4L. In 4L, the plunger of the switch is at position 4 and should have around 200 ohms.

The previous owner had tghe TCM/PCM replaced... I have no check engine light or codes, but I wonder if the replacement PCM has something to do with this.

But again, when I jump the plug, everything works perfect. Logic says its the switch, but reality is that I have 2 brand new in the box Mopar switches and both give the same results of nothing. Ugh.

The mystery is killing me...

 

[RUBI 4 MY MRS]

I understand all of that.

However the only way to verify the plunger is being pushed in the proper distance by the TC is to install the switch. You would not plug the wiring connector in to check resistance readings.

Now, with the PCM replacement info.

The Rubicons do have a different (programmed) PCM. There is one difference I know of that may affect this.

You don’t show what year you have but the ’03 & ’04 non Rubis have an open PCM pin at C-1 pin 14, the Rubis use that pin for the TC position sensor input.

The ’05-‘06s use C-1 pin 26. For non Rubis it is part of the sensor ground circuit but for the Rubis it is the TC position sensor input.

Also, as described in the FSM, it gets 5v to the switch & the PCM monitors the voltage output which makes sense but none of the wiring diagrams (’03-’06) show that. The FSMs are certainly not 100% accurate. Something is not right since the FSMs all show the “off road package” as having a simple on-off position switch which we know is incorrect.

With that said, I’m not sure that a Rubi’s lockers with a non Rubi PCM would work with the paper clip. But something to check into.

 

[Digger84]

Do you have a rubi pcm
And a rubi cluster

The non rubi clusters and pcm with the 231 use a simple open closed switch the 241 rubi case uses a linear resistor no switch and NO four positions you can feel on the plunger so when you say you feel the four positions it sounds like you don’t have the linear pot plunger that the rubi uses


The 242 switch used on some xj and zj has a 4 wire switch that has detents you could feel


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[fabil]

hi all.. I have a similar problem, but is not electronic. I think is fisical problem inside of transfer case.
Pressing the switch with my fingers, the resistence scales work perfectly, and the 4wd and espOff lights come on in each resistence range from switch.
but with the switch attached to transfer, I have this readings : 2wd = 1172 ohms 4wd = 1172 ohms ( wrong, 4wd light off ) Neutral = 215 ohms ( wrong, 4wd light ON) and 4low = 60 ohms ( wrong, espOFF and 4wd light OFF in the dash). The car not run in 4low, the engine not accelerate
The transfer case engage all positions properly, no noises, the oil drained is clear