4wd servo

[Rustypipes12]

My "new" 2024 RAM bighorn 2500 has just over 6k miles on it. Today I put it in 4wd on the fly (about 35mph) . It went into 4wd fine but another light came on that said "4wd serv". It then would not go back into 2wd. I drove it like that on the thruway back to Buffalo about 50 miles. I stopped at a club I belong to and was discussing it with one of the guys. When I came out the 2nd light was off and it went into 2wd just fine, I then went and babysat my granddaughter and on leaving the roads had iced over so I went to put it in 4wd and It told me it was unavailable. About a mile down the road I stopped at a convenience store and started the truck and it showed that it was in 4wd. It shifted in and out of 2to 4wd fine on the way home but I have to drive 115miles one way back and forth twice a week and this has me worried. I went to RAM's website to see about scheduling a service and apparently the site is down or my computer is blocking access. I'll call in the AM. I thought these ZF transmissions were supposed to be bullet proof!!

 

[olyelr]

My "new" 2024 RAM bighorn 2500 has just over 6k miles on it. Today I put it in 4wd on the fly (about 35mph) . It went into 4wd fine but another light came on that said "4wd serv". It then would not go back into 2wd. I drove it like that on the thruway back to Buffalo about 50 miles. I stopped at a club I belong to and was discussing it with one of the guys. When I came out the 2nd light was off and it went into 2wd just fine, I then went and babysat my granddaughter and on leaving the roads had iced over so I went to put it in 4wd and It told me it was unavailable. About a mile down the road I stopped at a convenience store and started the truck and it showed that it was in 4wd. It shifted in and out of 2to 4wd fine on the way home but I have to drive 115miles one way back and forth twice a week and this has me worried. I went to RAM's website to see about scheduling a service and apparently the site is down or my computer is blocking access. I'll call in the AM. I thought these ZF transmissions were supposed to be bullet proof!!

Its likely not an issue with the transmission. That would be the transfer case…or more than likely wiring/sensors for it.

I wouldnt be worried about driving like that for the most part…but it not coming out of 4wd or into 4wd when you need it does suck.

 

[crash68]

I thought these ZF transmissions were supposed to be bullet proof!!

The transmission is ZF but the transfer case is from a different manufacturer BorgWarner.
Not many problems are reported with the transfer cases.

 

[olyelr]

Sounds to me like the mechanicals of the tcase probably work just fine…just an electrical gremlin/sensor issue.

 

[Rustypipes12]

I think you guys that said it seems electrical are most likely right. After parking it then getting back in it everything is back to normal. I'll just have to keep an eye on it. I have a feeling if I take it in they won't be able to find a problem.

 

[dieselscout80]

A quick easy things:

Make sure all your fuses are fully seated.

Clean and check all of your grounds.

Check the connectors in that circuit to make sure they are fully seated and latched.

 

[olyelr]

It would certainly help the guy doing diagnostics if it was triggering a code that he could look into.

 

[crazy jerry]

take it straight to a dealer and check for error codes.
do not try to diagnose or fix it your self. theres many things that could of caused dash lights and someone familiar with the vehicle needs to look at it