Why does (Service 4 wheel Drive system) keep coming up on the warning panel and stopping me putting it into 4 wheel drive low?
Here is a paragraph I found on line: You will have to have it checked with a scan tool. ADDITIONAL INFO: This is a known problem with newer model Jeeps. It MIGHT mean this is an issue or it may not. I have had this problem with my 2006 WK (Commander) 5.7L and my 4WD still functioned properly. Unfortunately your only viable option is to take it to a 5 STAR Dealer and have it diagnosed, since this is a specialized system and most independent shops do not have the StarSCAN tool to service it. Chrysler DOES know about this problem and issued a Technical Service Bulletin on the subject.Please keep in mind that while Chrysler DOES know there is a problem, they are not required to fix it at no charge if it is not within a warranty period. This particular problem is NOT a recall.
Here is another solution I found. You may want to try this one first. I got the fix for this problem from another site. The actuator in front diff gets corroded from not being put in 4low enough so it stays stuck in. Also shortly after the N23 recall was done. Take the #25 fuse (e-diff) out in fuse box under the hood closest to the firewall. The "Service 4wheel Drive System" come on the dash steady. Drive around for abit then put fuse back in with engine running. Shut off engine then restart. My problem was fixed and it goes in and out of 4low now.
Jeep N23 Recall problems For starters, I have a 2006 Jeep Grand Cherokee Limited that I purchased as a vehicle to tow behind our RV. I have had no problems towing this vehicle 4 wheels down for seven years until getting the Jeep N23 recall fix. Since then it will periodically give the message to “Service 4WD System” when doing the procedure to put it in 4WD neutral for towing. We have actually had to leave our Jeep on the street when we had a service appointment for our RV 120 miles away because we couldn’t tow it. It doesn’t take much to find that there are thousands of people affected by this problem as quick Google search for “Jeep Service 4WD System” gets thousands of hits. The first few zero in on the problem for many started after getting the N23 recall fix. It turns out that after the fix the affected vehicles will eventually not be able to put the vehicle in 4WD neutral for towing or in 4WD LOW for off roading. The reason for the recall is that a cracked circuit board that controls the 4WD Low and 4WD Neutral can cause the vehicle to go into neutral when stopped in park. This could result in the vehicle rolling away when parked – across a parking lot or worse, down a hill. That of course, assumes that people don’t use their emergency brake when parking. So instead of fixing the cracked circuit board Jeep came up with a software fix. You DON’T FIX CRACKED CIRCUIT BOARDS WITH SOFTWARE. So what did they do? Apparently they fixed software in the FDCM – the Final Drive Control Module. The FDCM is a different component that apparently takes instructions from the cracked circuit board, but has the ability to override that board. When you have different electronic components that communicate with each other that is usually called a Distributed Control System. It is distributed because each module takes care of its own function so you don’t need one big computer running everything. So it appears the circuit board that might crack controls the 4WD Low and neutral and the FDCM transfers control to that module when that function is needed. I work with DCS systems, my guess is that the reprogramming of the FDCM added some diagnostics that check for signals from the board that controls 4WD Low and neutral. When the signals indicate the board might have the crack that initiated the recall, the FDCM prevents that board from ever taking control of the 4WD drive system. When you try to use 4WD low or neutral you get the only message that was available in the FDCM to display – “Service 4WD System”. This is a cheap patch that doesn’t fix the problem – a cracked circuit board that should be repaired or replaced. The internet is full of how to temporarily fix this problem. You open the hood, find the fuse box with the FDCM fuse, remove the fuse, start the vehicle and move it back and forth a few feet and turn off the engine. Then you replace the fuse and now you have 4WD control again – for a while. On my 2006 Jeep Grand Cherokee it is Fuse #25. The fact that many people are able to fix the problem with this fuse trick tells me that my circuit board is probably OK – or the warning message would come back immediately. I expect that the software patch that looks for a problem may be responding to intermittent noise instead of a solid indication of failure. Perhaps even electrical spikes from starting the engine or cycling the AC compressor might give a spike that the FDCM counts a failure and then locks out the 4WD control. With this kind of control systems they should be able to add a little more logic to not only detect conditions that indicate there might be a problem, but also do some testing to be sure that the problem is solid and not an intermittent. For example something as simple as putting time delays on the inputs to make sure that the indication of a bad board stays for more than a second or two. Or add some subsequent testing to make sure that the problem exists a few minutes later. And if it doesn’t, then reset the lockout. Jeep appears to be taking a big risk with the cheap fix. They admit to knowing they have a problem with a cracked circuit board. You don’t fix a cracked circuit board with software. They should fix or replace the circuit boards. We buy these vehicles because we expect some kind of quality from Jeep. As the word spreads that Jeep has screwed up the most desirable feature and is willing to cripple the vehicles rather than provide a real fix the word will get out and they will suffer like GM was over the problem with their ignition keys. Instead they are in DENIAL that this problem exists. From internet postings it appears to have become a CASH COW for less than reputable service departments. They deny that they’ve heard ANY complaints from people having this problem and proceed to try to sell new actuators or other fixes. The follow up posts often tell how they pay hundreds of dollars for fixes and then the problem comes back. These are growing and may soon hit a critical mass that could be severely damaging to the Jeep reputation. And heaven forbid that someone is killed or injured because they get caught in an off road situation and can’t get into 4WD low when they need it. Or someone who tows their Jeep behind an RV has to leave it in a bad location because it won’t go into 4WD Low and has it stolen or damages while they drive their RV to some place to get help. Chrysler Jeep needs to take responsibility for this screwed up fix and do a real N23 fix. Even if they have to spend a lot of money on circuit board replacement labor, it may be well worth it to protect the brand.
If Jeep doesn't step up and recall the N23 recall and actually fix the problem, this will be the LAST Jeep I ever buy! Chrysler also needs to recall the 4.7 and fix the exhaust leak from the rear of the exhaust manifold - BIGGER BOLTS! Bought my '06 Grand from a "certified" used dealer. I get the check 4 WD System and have the exhaust leak. Fortunately I discovered both within days and took it back. They replaced the actuator and 4WD worked for a while... The just listened for the exhaust leak at idol and told me iI was hearing a injector... Well now I am taking it back again tomorrow. I'll be popping the hood & revving the motor so the service writer will hear the exhaust. Don't know what they will try next with the 4x4 System. Hopefully undoing the reprograming of the FDCM and somehow checking for a cracked circuit board... Or buying this piece of cr#p back.
I had the Sam symptoms and replaced both 20A fuses FDCM and FDCM EDIFF, though nether was blown. The 4WD started working again. Maybe terminals were corroded.
2010 Jeep Grand Cherokee Limited 5.7l HEMI Wow that fuse fix really works. With the engine off I removed fuse #25 as described above "Service 4wd System" did not appear on EVIC system. So I got out my factory manual and found the (e-diff) FDCM – the Final Drive Control Module was actually fuse #33. I removed it, started the engine, and "Service 4wd System" came on and stayed on. Just as the person in previous post had stated. Drove down the block and back to my home put the fuse in while engine was still running."Service 4wd System" stayed on until I then turned the engine off. Waited about 10 seconds and started the engine there was no "Service 4wd System" warning. I noticed the green light on 4WD Lo was now on. Put into neutral then lifted the T-Handle and 4WD Lo lit up on the dash ESP off on the dash as it should. Tested the 4WD Lo and just by the high RPM's I could tell I was back in business. Turned the vehicle off and on tested 4WD Lo several times and worked great. Thanks for the info Reelin68 saved my a fortune.
This worked for my 2006 Commander w/4.7 and is similar to other guidance provided: Under the hood, remove the #25 fuse (e-diff) from the fuse box closest to the firewall. Start the engine and the "Service 4 Wheel Drive System" message comes on and stays on. Wait 10 seconds and turn the engine off. Replace the #25 fuse. Restart the vehicle. Place the gear selector in "N" and engage the Low 4 by pulling up on the "T" switch. My problem was fixed and Low 4 works correctly. And the Chrysler engineers could not provide this solution why?
@2010Grand4WD. Duplicated your efforts with the same results, thanks for the info.
Just worked on my 08 gc limited 5.7. Thanks for the help
I have a 2006 5.7L Commander. Started with the symptom about this time last year. It was diagnosed as the transfer motor BUT there were non available, I was told there were 1000+ on back order!! Finally towards fall of 2014 (Oct) I asked if the motor was available. Yes, will cost a$600+ and CANNOT be returned. So I had them put in a new motor. It did NOT fix the problem. So back in for service and they tell me in the morning that they had to replace some wires and a ground wire? Later in the day they told me it was the module which is apparently under the rear seat, BUT it is not available as it is on back order. Received a call last week that part came in. Brought in this past Monday. Received a call later in the day that it did NOT fix the problem. They want to speak to Jeep (Chrysler) about the problem. Brought Jeep back in today ....they called and told me that it was the transfer motor!!! The new one put in (and never actuated) was bad?? They said they put another one in and the symptom went away. So I have waite for about 6 hours for them to call and say to pick up the vehicle, never heard from them so I called...was told they would have to keep it longer??? I did not ask why, but based on all of the questions and responses in theis forum, I truly believe that there is a problem that we are not being told abou. I am into this one problem for over $1,00 and I am P.O.'d
Ecb43, did you try the fuse trick listed above?
Thank you Reelin68, I did try that a couple of months ago with no luck....It is of course possible that I did not do it in cottect sequence..... I just picked up my Jeep 1 1/2 hours ago. So far so good, I'll probably nevr know what was really wrong, but as I mentioned earlier, I am into it for $1,000 plus, probably more like $1,400!! As an aside, I had a wierd thing happen in the last 3 weeks. While catching a flight to FL on Jan 1 I left my car at a parking facilty that does light maintenance and detailing. I had the Jeep detailed in and out. My Son picked up the Jeep a couple of weeks before I came back and he mentioned that the warning "lift gate open" or something like that was on and the lift gate was firmly closed. He was not in a position to take it back to the detailing shop and I told him I would look in to it upon my return. When back home I googled and did not find anything much on that symptom and decide to have it looked at at the Jeep dealer when they were servicing the service 4wd symptom. The night before my service appointment I went to my bank.....when I came out my wife made the remark that I backed into some low bushs...I said yeah OK, no damage as I did not know that I had....as I am driving out of the parking lot we notice that the 'lift gate" indicator is not on and it is not "dinging"!!! It has NOT been seen since!! Now, my "service 4wd" indicator came on after I had backed into a snow back last year. I had backed into the snow bank (not hard) and went in to a bldg. for an hour or 2, when I came out the service 4wd was on and has not been out until today....weird..
Just did it to my 06 Grand Cherokee 5.7L HEMI. Worked as stated. Pretty simple. Now gonna tow the Jeep 2200 miles round trip to NOLA. Peace Ya'll. ==chuck
Just did this fuse swap to my commander 56 plate and worked a treat selects 4wd low turns traction control off like it should yet hour ago it wouldn't thank you thank you been puzzling this for weeks
Hello dave & sec0pz... I must not have done the correct sequence....so it took me almost a year and $1,400 to finally have it working! Thank you though for verifying what has been said in this and other forums.
That OK just thankful I read this post .I phoned dealership local to me for advice and they informed me that 4wd low makes the car ride height lower than usual for off roading. Which is hilarious
So I thought my service 4 wd problem was over, but this past Friday I tried to put it into 4 wd low. I all have to admit I do not remeber EXACTLY what happend, but it did not go into 4wdlow and then the service 4 wd indicator came on!!. Due to the snow I preety much had to use the Jeep, while the 4wd indicator was NOT on It felt like *based on RPM's as well) that I was in 4wd low. I drove to my office. When I came out a short time later and started the vehicle, the 4wd low indicator was on!. I puuled the lever to disengage and it seemd to go fine. I have NOT tried it again as I made an appointment to bring it in this coming Wed. So then Sat morning I left the house and was driving to the office, all of the dashboard indicators came on and I realized that I had no power. This lasted only a couple of seconds, all indicators went out and I had power....I kept driving and it happened again (2 more times) I thought about the pending recall for the ignition switch and wiggled the key very lightly.....so far it has not happend again. (If I address this further I'll put it in another thread).
You should update the results on this thread, because people will most likely miss out on the solution. That's the biggest downfall of sites like this one. There should be a solution box for the person who started the thread. So often, people offer up solutions to the posters question, and you never hear back. It almost defeats the purpose.
It works!! I removed both fuses FDCM and FDCM EDIFF, started her up, drove a few min, put both fuses back in with engine running, turned engine off for 10 seconds and started her back up. 4 wheel low began working again! Thanks!!
Worked for me too. Just wanted to note, follow procedure as described. At first, I removed fuses (25 and 33), drove around, turned off, put fuses back in, still had problem. I did it again, removed fuses, drove around, KEPT ENGINE RUNNING and put fuses back in while engine running, then shut off engine, then started back up, and good to go. Thanks for the info!
Ive just done the above to my2006 GC and it worked first time. Thank you very much.
Did my 2006 Grand Cherokee today. Would not work if removed both fuses so removed only #25 ,started,drove, put fuse back in while running,shut of 10 sec and restarted - system now works.suspect n23 tightened the parameters for system interrogation and fdcm will eventually turn tccm back off and I will have to do this again. This may not be a fix but only a system reset - time will tell. Autoweek article dated February 20 addresses this issue and it seems perhaps Chrysler may now have a fix - offering case by case "gratis". No word yet on what the fix is
Hi everyone I would like to say a great big thank you for all your answers to my question about the 4 wd low problem. I have not had a chance yet to try this out on my 55 G C but hope that Chrysler come up with the answer, after all it is a fix problem for the company. So fingers crossed everyone and let's hope they have some thoughts for all the customers who bought a JEEP.
To finish my earlier entry about vehicle ignition switch and 4wd low... I made an appointment with Elmwood Dodge for Wed Feb 11, BUT on Tues night I cancelled due to a predicted snowstorm. Have not had a chance to get the jeep in to Elmwood Dodge due to more snowstorms and work priorities. Tues Feb 24, 2014 Around 4PM while driving out of my driveway the 4WD Low service light came on. There was no indication that the vehicle had gone into 4 wd LOW, but I tried to disengage - engage the 4WD low but no change in the indicator. This has been a persistent problem for a year and figured I could drive the vehicle, but after a few hundred feet on the road the car was acting as if it was in 4WD Low but different, when I slowed down and then tried going forward again there was a clunk towards the rear. I brought the Jeep home into my garage. I had been in touch with Scott (and Jimmy earlier) to make a plan to get it to Elmwood Dodge...thought of having AAA pick it up as I did not know if driving it would damage anything. Wed Feb 25, 2015 Due to what happened on Feb 6 (indicator went out after sitting for a while) I checked the vehicle the next morning and the 4wd low indicator was not on!! And it seems to be driving normally. Will check with Elmwood on leaving it for service. Later in the day I stopped at Elmwood and spoke with Jimmy (svc-mgr) & Scott. Jimmy asked his lead tech to look at the error history. There was NO indication of an issue in the history. I was told to wait until it happens again and bring it in!! While I sort of understand that when a problem is intermittent it is difficult to fix, what I am concerned about is that this “service 4 WD “ had been on since last Feb or so and never gave me a problem other than not being able to shift into 4wd low. Since the most recent repair which I assume is the new module and another xfer motor, the vehicle has had a REAL issue in that it has gone into what appears to be 4 wd low (or partially) on its own!! boy I really hoped to drive this vehicle "forever", but now I have safety concerns.
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