Weird 4x4 issues

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PaulTGarrett

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OK, here's a new problem I haven't seen anyone talk about.... On my 2012 RAM 2500 CTD, I have the good ol' manual floor shifter for my transfer case. NO electronics in the 4x4 shift chain. Transmission shifter is on the column, no knob on the dash.

First problem... When I shift to 4 Low, the EVIC explodes with all kinds of flashing "Service 4x4" messages that randomly come on and off. The xfer case shifts to 4 Low and works fine, just get the error message. 4 High works fine with no error message issues. More than a bit annoying. I don't use 4 Low that much so it has been much of a concern, just want to get it fixed.

Second problem... Transfer case is in normal 2-by position, driving around town it works fine. Driving down the interstate for any extended length of time (say over an hour) the 4x4 light starts to flicker on and off, then finally comes on and stays on. If I move the shifter up and down a bit I can make the light go off, but then it comes back on as soon as I take my hand off the shifter. My thinking is a heat-related problem. Something is heating up juuuuuust enough to trip the 4x4 light sensor but doesn't get hot enough to trip it when I'm doing my daily driving around town. Oh, doesn't matter if I'm towing a trailer or not.

Any ideas?
 

Brandon-w

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Could be the indicator sensor on the t case it's self. Not sure if they're like the old chevies in this case but if they are there's a ball and detent system that detects being in a certian gear id look into that first. Do you have alfaobd?
 

jws123

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My fathers 2012 ram 2500 does the same thing whatever sensor tells the position is the issue. I cant remember why I didnt replace it think it was expensive but all we did was move the lever a bunch of times finally found the sweet spot where serv 4x4 no longer pops up.
 

62Blazer

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Definitely sounds like a sensor or wiring issue. I don't think physically it's trying to randomly shift just going down the road but if you have a shorted out wire or bad sensor it is giving a faulty signal. I know you said the transfer case was going into low range, but did you verify the front axle was actually engaging.....meaning the front axle disconnect was engaging?
In any case the first thing I would do is a good visual inspection of the wiring, connectors, and sensors and make sure nothing is loose. Next step would probably to get a good scan tool that shows real time data and see what the 4wd related sensors are actually doing, and check for any fault codes in the system.
 

Jane S

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OK, here's a new problem I haven't seen anyone talk about.... On my 2012 RAM 2500 CTD, I have the good ol' manual floor shifter for my transfer case. NO electronics in the 4x4 shift chain. Transmission shifter is on the column, no knob on the dash.

First problem... When I shift to 4 Low, the EVIC explodes with all kinds of flashing "Service 4x4" messages that randomly come on and off. The xfer case shifts to 4 Low and works fine, just get the error message. 4 High works fine with no error message issues. More than a bit annoying. I don't use 4 Low that much so it has been much of a concern, just want to get it fixed.

Second problem... Transfer case is in normal 2-by position, driving around town it works fine. Driving down the interstate for any extended length of time (say over an hour) the 4x4 light starts to flicker on and off, then finally comes on and stays on. If I move the shifter up and down a bit I can make the light go off, but then it comes back on as soon as I take my hand off the shifter. My thinking is a heat-related problem. Something is heating up juuuuuust enough to trip the 4x4 light sensor but doesn't get hot enough to trip it when I'm doing my daily driving around town. Oh, doesn't matter if I'm towing a trailer or not.

Any ideas?

Second problem... Transfer case is in normal 2-by position, driving around town it works fine. Driving down the interstate for any extended length of time (say over an hour) the 4x4 light starts to flicker on and off, then finally comes on and stays on.

I had a similar issue.
Get under the truck and look at the shifter linkage from the top to the bottom. There are rubber and plastic parts that wear out. Strange but true.

Let us know if that is the issue.
 

Jeepwalker

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You might try moving it in/out of 4x and into 2wd many times ..in your driveway. Could be there's a switch down there that's just not making good contact or gummed up contacts. Actuating that switch a bunch of times might make it contact better. Won't cost anything to try. I have a Jeep that does something like that come fall ...after the 4x hasn't been used in many months. Move it in/out of 4x several times does the trick. There's a module on the side of the Jeep Xfer case that's the mode position switch. Some guys take them apart and clean too. If that doesn't work see if there are some Y/T videos on your problem.

If you know someone who has a good scanner, they should be able to see (via the scanner) if there *was* an Xfer case position switch and IF it was making the proper contact or not. In other words, as you move it through it's 2wd/4wd positions, the switch/s should change. That's probably what a dealer would do. A Snap on scanner should be able to see that too. as well as AlfaOBD and other 'good' scanners. Just a thought.
 
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PaulTGarrett

PaulTGarrett

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Second problem... Transfer case is in normal 2-by position, driving around town it works fine. Driving down the interstate for any extended length of time (say over an hour) the 4x4 light starts to flicker on and off, then finally comes on and stays on.

I had a similar issue.
Get under the truck and look at the shifter linkage from the top to the bottom. There are rubber and plastic parts that wear out. Strange but true.

Let us know if that is the issue.
I had that problem on my '98 RAM 2500 except I noticed one end of the linkage dangling from the shifter... That was an easy diagnosis! LOL And of course found out that RAM/Dodge/Fiat, whatever they call themselves this week, will not sell you the individual rubber pieces (or window regulator rollers). I ended up just buying the linkage including the rubber bushings off of someone on eBay... For a third of the OEM cost. Installed them and the shift problems on that truck went away... Hadn't really thought about the shift linkage since it's good and firm but it's worth a look. Will let you know! Thanks!
 
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PaulTGarrett

PaulTGarrett

Grumpy old man
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Location
Tampa Bay, Florida
Ram Year
2012
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408 Cummins Turbo Diesel
Definitely sounds like a sensor or wiring issue. I don't think physically it's trying to randomly shift just going down the road but if you have a shorted out wire or bad sensor it is giving a faulty signal. I know you said the transfer case was going into low range, but did you verify the front axle was actually engaging.....meaning the front axle disconnect was engaging?
In any case the first thing I would do is a good visual inspection of the wiring, connectors, and sensors and make sure nothing is loose. Next step would probably to get a good scan tool that shows real time data and see what the 4wd related sensors are actually doing, and check for any fault codes in the system.
No front axle disconnect, solid front axle rotates all the time, 4x4 engaged or not. Locking hubs/full float spindles are on my wish list. I have thought about setting the truck up on stands and verifying engagement but that is a LOT of truck to jack up in the air. Recycling yard weighs my truck in at 8200 lbs empty! Local tire shop won't do it, they already say my truck is too big for their alignment set. Visual inspection of the cables and connectors show nothing obvious, shot some contact cleaner into the connectors for good measure but no change in the problems. A "good scan tool" is also on the wish list, the local Advance Auto Parts store's scanner tool doesn't show any transfer case errors. I would hate to spend the $$$ but given the age/mileage of the truck I may just shotgun all of the sensors. Thanks!
 
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