Originally Posted by CumminsKingRanch
I recently purchased an 08 Overland for my DD so my truck can be my toy (Cummins swapped Super Duty). All has been well until the other day, the dreaded "Service 4WD System" message popped up on my way to work. I tried the fuse trick, no dice. Then today it went away on my way home, so I tried 4low when I got home and bam, it came back. So heres where I am at:
Searched the Jeep recall database, it says both the N23 and P73 was done. I have no found anyone with probems AFTER the P73 was performed, has there still been issues?
Carfax shows that a new Tcase was installed a few months back, at a Jeep dealer. Also appears that both drive shafts are new, because they look brand new, as does the Tcase. Not sure if it is a reman or not.
I do not get any other lights on the dash so I do not suspect a wheel speed sensor, as they usually throw ABS lights etc, or is that not always the case?
I was leaning towards a new front diff actuator since it is cheap.
However, it appears that the Tcase shift motor is not new, so it is most likely original.
I have not brought it to the local dealer yet, I am not ready to pay $150 or whatever for a diagnostic when they will probably not blame it on the N23 as it was updated to the P73 flash.
So where I am at, I was thinking, change front diff actuator, see of that fixes it. If not, swap out Tcase shift motor. Or am I just throwing parts at it at that point?
This was a one owner vehicle, almost exclusively dealer serviced according to its records.
I do know, I did the "key dance" last night, and when I turned it on, it went into 4LOW despite saying Service 4WD System, which I thought was odd. I had it in 4LOW a few weeks back and used hill descent, so it wasnt lurking till I tried 4LOW, as this all startesd just driving down the highway.
Also, does the ELSD still work with the 4WD message?
First off, allow me to formally welcome you to the forum - albeit somewhat late, sorry about that.
I was not yet appointed a forum moderator at the time when you joined the forum.
I don't know if you ever got this resolved or not because you never posted again - but I do see you cruising the forum on occasion, so, I figured you deserved some type of response - even if it's a late one.
There are a few members here that have said they needed to have the P73 flash applied three times consecutively for it to take on their FDCM.
That was not my experience - but there are a few reputable members here that have confirmed it needed to be done that way on their particular Commanders.
If that doesn't solve the issue, the next likely cause would be having the actuator motor on the transfer case replaced.
I can't answer your question about the ELSD other than to say that I would not try to drop down into 4-LOW while the "Service 4WD System" message is being displayed as you could potentially cause damage to your transfer case - or other related components.
I'm also attaching a copy of the P73 customer satisfaction notice if you would like to read it.