help with 4x4 engine code (P0836)

[reflection]

Hi,
i am new to jeep and this forum
i have a jeep libery 2004 and yesterday i did a check engine diagnostic and it gives a code p0836
i searched google and find out that it means:

Symptom: P0836-4WD MUX SWITCH STUCK
When Monitored and Set Condition: P0836-4WD MUX SWITCH STUCK
When Monitored: When Transfer Case in 4WD Low.
Set Condition: Four wheel drive (4WD) muxed switch input detected below minimum or above maximum acceptable voltage.

POSSIBLE CAUSES
transfer case position sensor input circuit open
transfer case position sensor input circuit short to ground
transfer case position sensor input circuit short to voltage
transfer case position sensor input circuit short to sensor return circuit
transfer case position sensor
powertrain control module
intermittent operation

when i put my jeep in 4x4 mode there is no 4x4 light comes on at dashboard

so my questions are;
1- is my car works correctly when i use 4x4 but car does not realize it? (since its about sensor malfunction)
2-how can i test if my 4x4 works or not without going to the service?
3- where does this sensor located, and how can i find a replacement
4- i am using my jeep 2x4 nearly all the time (it is more economical ) do i need to change the sensor anyway?

any help would be appreciated

thanks

Caner.

 

[dude1116]

Transfer case position sensor is faulty.

1) Jeep is using 4x4 correctly
2) Pull the lever up on a dirt road and mash on the accelerator without flying into a tree.
3) On top of the transfer case; Rock Auto or Stealership
4) No you don't need to change it. But I changed mine due to the fact that it was throwing a CEL, and I needed to get an inspection.

Two ways to change it. From above (in the cabin, under the console) or from below. All of the information is here:

http://www.jeepkj.com/forum/f202/how-change-transfer-case-position-switch-44188/

I suggest going from below. It's a bit of a stretch BUT once you know where you're going and how you're doing it, it's a 10 minute job.

 

[reflection]

thanks a lot for the info.

i have a one last question,
lets say i use 4x4 full time and car didnt relized it because of the faulty sensor. are there any drawbacks for this situation? i mean like, if car could read the sensor it would adjust some 'things' (sensor values, pressure values, fuel consumption etc.) according to 4x4 and now it doesnt know i m using 4x4.

i mean is transfer case position sensor is just for the dashboard light to come up?

thanks

 

[ftaa]

yes it is just the light on the dash ... dont use the 4x4 on dry pavement you will wreck stuff.

 

[dude1116]

thanks a lot for the info.

i have a one last question,
lets say i use 4x4 full time and car didnt relized it because of the faulty sensor. are there any drawbacks for this situation? i mean like, if car could read the sensor it would adjust some 'things' (sensor values, pressure values, fuel consumption etc.) according to 4x4 and now it doesnt know i m using 4x4.

i mean is transfer case position sensor is just for the dashboard light to come up?

thanks

APPARENTLY it affects low-end torque in 4-LO but that's about it. Everything is still usable under normal operation.

I wouldn't use 4x4 on dry pavement...but IF you have the FULL-TIME option in the SELEC-TRAC transfer case, then yes you should be OK.

 

[reflection]

thanks dude1116 and ftaa :worship:

 

[ftaa]

APPARENTLY it affects low-end torque in 4-LO but that's about it. Everything is still usable under normal operation.

I wouldn't use 4x4 on dry pavement...but IF you have the FULL-TIME option in the SELEC-TRAC transfer case, then yes you should be OK.

at this time with it being broken and probably not knowing what transfer case he has... just remeber to put it in 2 hi LOL

 

[reflection]

i put it on 4 full time today but it changed to 4 part time i think.
now tire tires are making this slipping noise when i try to turn.
i cant get it back to 2 hi, i tried everything but it looks like it stuck on 4x4 part time

what should i do? do you have any recommendations?

edit: i dont know how but somehow i manage to put it on 2hi again.
i guess the fault is not just 'about the sensor'

 

[TwoBobsKJ]

i put it on 4 full time today but it changed to 4 part time i think.
now tire tires are making this slipping noise when i try to turn.
i cant get it back to 2 hi, i tried everything but it looks like it stuck on 4x4 part time

what should i do? do you have any recommendations?

edit: i dont know how but somehow i manage to put it on 2hi again.
i guess the fault is not just 'about the sensor'

If you move the handle all the way down - and assuming the linkage isn't broken - then the Jeep will be in 2HI.

If you move the handle up one position it will be in 4WD Part Time; move it up until it hits the "gate" then it's in 4WD Full Time. If you move the lever to the right it will be in Neutral; move it further right and up one more position it will be in 4LO.

Double-check the linkage underneath - if it is intact and not broken then you can ignore the dash indicator lights until you get the sensor fixed. Learn what the different positions feel like when you move the handle (sounds dirty, doesn't it? :mexsmoke: ) so you'll know what mode your drivetrain is in no matter what the dash lights say.

Bob

 

[reflection]

If you move the handle all the way down - and assuming the linkage isn't broken - then the Jeep will be in 2HI.

If you move the handle up one position it will be in 4WD Part Time; move it up until it hits the "gate" then it's in 4WD Full Time. If you move the lever to the right it will be in Neutral; move it further right and up one more position it will be in 4LO.

Double-check the linkage underneath - if it is intact and not broken then you can ignore the dash indicator lights until you get the sensor fixed. Learn what the different positions feel like when you move the handle (sounds dirty, doesn't it? :mexsmoke: ) so you'll know what mode your drivetrain is in no matter what the dash lights say.

Bob

Hi Bob,
there is no dashboard light coming up in any slot.

it feel like something get loosened up when i changing the position.
when i put it on 4wd part time it doesnt feel like anything has chanced but when i pull the handle more and put it on 4hi then something changes and i thinks it changes to 4wd part time instead of 4 hi.
it is like, it follows 1 gear before

same things apply when i change the gear back to 2hi,
it gets stucks on 4wd part time (1 gear before) i need to push it much harder to get it on 2hi (since there is no 1 more gear furter i can't put it back on 2hi easily)

i am thinking if the handle connected via something like cord or cable maybe thats also loosened up and i can't put it on the exact gear i wanted

i dont know if all these makes sense but this is the only explanation i found reasonable :emotions34:

what do you guys think? you think it is possible?

 

[TwoBobsKJ]

i am thinking if the handle connected via something like cord or cable maybe thats also loosened up and i can't put it on the exact gear i wanted

i dont know if all these makes sense but this is the only explanation i found reasonable :emotions34:

what do you guys think? you think it is possible?

Yes, if the linkage - which is partially a cable - is stretched or the bushing from the cable to the lever on the transfer case is missing then it won't shift properly.

I agree with you that something is too loose in the linkage. Have that checked out to make sure it's connected correctly then you can work on the position switch.

Keep us posted!

Bob

 

[twowings]

have someone work the linkage while you observe from underneath...you should be able to watch as the mechanism moves...

 

[libertybob]

Transfer case bushing

The bushing on the transfer case cable was missing on my KJ. I bought a nylon bushing at Loew's. The bushing I bought was 5/8" od x 1/4" id x 3/8" wide. I drilled out the 1/4" hole to 5/16" for the input shaft stud. I used a wire clip snapped onto the input shaft stud to hold the bushing on the stud and in the cable. Works great and costs less than $2.

 

[profdlp]

^ I think Leeann did something similar. Great idea. :favorites13: