4 Wheel Drive (4WD) Not Working

[awjohnston14114]

Its pretty sad that you should have to do anything special to get the darn 4 wheel drive to do what its supposed to do!! I had same issues numerous times and had truck in shop a couple times, they cleared "codes" and "computer issues", all which failed again to ultimately need to replace Axle Actuator... I guess this is the cause; it only took 3 tries. I have owned new trucks since 1989 and not ONCE did the trucks ever fail in 4 wheel drive even after 120K miles of beating the hell out of it. This thing with 20K doesn't work for nothing.

 

[mk construction and reno]

I just had this exact issue. Mine was a bit different. I was getting the 4wd service light while driving in 2wd on the highway. Not trying to select or anything. Then the Stabilitrac Light would come on. Everything would reset with no messages when I got in to drive it. Then would come back about 20 miles or so. Sometimes sooner.

I took it in to get looked into and they did a flash for a recall and another recall for the wipers. Said it fixed the issue. 25 miles into driving home it came back again.

I took it back, did't hear from them for 4 days so I called. Said they were installing a new Module (likely the TCU) but I didnt ask. When I picked it up they showed me that my issue was refered to FCs Engineering group for trouble shooting because they couldnt fogure it out. So they told them to swap the box after taking pin out readings and some where off.

The light is now gone. However, now it snowed a little so I wanted to put it into 4wd auto. Nothing just a blinking light. Tried in park, neutral, while driving on the fly nothing. Tried at a stop, 4hi, on the fly into hi nothing just blinks. Stopped tried 4lo, just blinks. This is were I am now. I will try again from 4lo first then cycle. But i seriously just got it back Tuesday, and started to search and found this post. I am glad the roads where not worse. I am going tobtry again. If it happens again, I am filming it, taking it back again for warranty work. I probably should have made a new post about this but I figured I would share in here what I got going on now too.

I had exact issue on my 2021 2500 HD Cummins - had 400 miles on it and 4WD service light came on while driving down the highway in 2WD! Stopped for gas, restarted and the light disappeared-did not try to engage 4WD at this point. Tried to engage 4WD the next day when it was raining and the service light came on and this time it stayed and 4WD won’t disengage. Took to the dealership- they said its FAD actuator problem and ordered replacement. Now back at dealership waiting to get actuator replaced. I found this forum just now so didn’t try the cycling thing. Registered to the site and will update on the issue. Hope replacing the actuator works! Super bummed to have issues with brand new truck..

 

[Badmonkey]

Sounds like the same issue I had. I have not had issues since it was replaced. Love the truck, glad they found the issue and fixed it.

 

[mk construction and reno]

Yes love the truck, It’s a beast!
So the actuator replacement didn’t work at first-they made f/up appointment but everything started working normally 24 hours after replacement! Then the 4WD service light came on driving down the freeway in 2WD again! Took the truck back and did multiple diagnostics and fixed the issue - the tech said there was a damaged pin that they had to repair/replace and it’s working fine now. This is what it says on the report “found a bent connector in xy260a -repaired connector and cleared code 8255”- hope it helps someone!

 

[stormcom]

I had mine not light up the 2wd / 4wd light under the shifter. Cluster says 4wd high but no light on switch. Let it sit 3 hours and it will work until it is shut off. Then it may or may not light up. Any ideas? We are in North Texas and do not use 4wd auto except a few times a year (This year we had 2 ice storms). Any ideas?

 

[Iceman22]

I have a used 2019 Ram . Just over 36,000. I have had the Serv 4x4 light with service 4x4 message when it's cold (snow) twice i have taken it to the dealer for wiper motor (unrelated) 20 mile ride. By the time I get there 4x4 is working. They cleared the codes and said no problem. They said i need to leave it so I guess that's next. Can't believe that not having 4x4 in the snow at start up is normal or acceptable. Will post if I find anything out. Appreciate any input.

 

[js_rv]

This happened to me when I bought mine in September, while in park try cycling it starting with 4low, 4high, 4auto, then back to 2, for some reason that worked for mine, haven’t had a problem since ‍

Thank you for the tip. I just bought a 2019 Ram and tried 4auto, it did not work. I followed your suggestion, it works now. I was started to worry ( that i might have to take it in) which is a nightmare in my town.

 

[Big_D]

I've seen a lot of good advice and I've tried several things. I have a 2019 Limited for a little over a month. Well about a week ago I went to use 4wd. My 4wd auto seems to work fine but I am unable to use 4 high or 4 low. Anything else I can try or look at before I start replacing parts?