Awww nuts. Add my name to the list. I started to get the dreaded red icon the other day and the Suspension Fault - Max speed 30mph warning.

Here is the readout from my IID tool:

Instrument Pack

U0102-87 (28) Lost communication with transfer case control module - Bus signal/message failure - missing a message
U0132-87 (28) Lost communication with ride level control module - Bus signal/message failure - missing a message
U0159-87 (2E) Lost communication with parking assist control module - Bus signal/message failure - missing a message
Suspension

C1A07-62 (2C) Cross articulation - Algorithm based failure - signal compare failure
Vehicle Dynamic

U0132-87 (08) Lost communication with ride level control module - Bus signal/message failure - missing a message


So, I'm not sure why I'm getting so many communication errors, but does anybody have advice on the Cross Articulation failure? As a little bit of background, I just replaced my dryer desiccant and reinstalled the compressor a few weeks ago (I don't think this is the problem). Immediately after that, I replaced all of my height sensor rods with shortened ones, then recalibrated the suspension w/the IID tool. Everything seemed to work great for a while, but then I got the red icon and a bing while driving about a week ago. Pulled over, turned the car off and back on and it was gone. Car raised back up and I was good to go.

However, I keep getting the bing/bong and red icon randomly now. It only seems to happen once per "trip", but goes away when I pull over and restart the car. Is there any way to tell if it's a bad height sensor, and if so, which one? The only thing I can think of is to leave the IID tool hooked up and record the live values for a trip to hopefully get the values when the failure occurs.

 

Why are you running shortened rods if you own an IIDTool? Since saving a set "lifted height" in the IIDTool, I've never used my shortened rods.

The only time I ever got a cross-articulation error (which, by the way, is the most likely reason you're getting the red icon) was when I had a suspension that had lost an airspring on the trail. I may've snagged and ripped the wiring to the height sensor as well (that wound up happening, I just don't know if it happened before the X-art error or in the shop). I would definitely check all your live values and make sure that they are within the acceptable range and also not too disparate from each other.

If they are and need re-calbirating, the guys at GAP are outstanding when it comes to customer service and I'm sure they'd walk you through the process.

 

To answer your question:

I posted this on another forum as well, but the main reason I am running both is because of where my suspension was already calibrated. It was already calibrated a bit on the high side, and basically, I was left with about 30mm of adjustment with the IID tool. Maybe I'm being greedy, but I wanted the 2"-2.5" lift available with the rods, but I didn't want to have to remove and reinstall rods all the time and I don't want to be running around town lifted (my wife drives the car too and she is prone to forget to check parking garage heights).

Anyway, my solution was to buy adjustable rods, shorten them slightly from the stock length and then recalibrate with the IID tool. This meant I was calibrated in the 175mm range (still riding at stock height) and had a full 3" of lift possible by hooking up the IID tool just before getting on the trail (in addition to another 2" via "off road" mode if I really needed it, though I don't think I'd try using that)

So, by reading your post, do you think that one of the height sensor wiring connectors may be loose or do you think a height sensor is bad... or is there just no telling at this point?

 

It sounds like you had an express purpose in mind with using both. Seems to me that regardless of where your initial calibration is, the EAS has its limits in terms of how high you can go and using the rods would not help. If it were me I would just run stock rods and stock height (albeit taller than most from what you're describing) and use the IIDTool to get that extra 30 MM out of it when you need it.

Can't you use the IIDTool to calibrate it lower (without the mod-rods on) and save that as say "MYSET.1" and then save a trail setting, say "MYSET.3" and be done?

Without delving into it I think the use of both methods is confusing the $hit out of your EAS. As for your other questions; the wiring harnesses and the overlay are all very easy to check! I couldn't say, without your vehicle being in front of me; but go check it out...and please keep us informed.

Best of luck.

 

The communication errors are the Ride Control Module's way of disabling related systems. Fix the suspension issue and more than likely, the communication faults should not return.

Some models had a service bulletin for Cross Articulation faults. It involves new sensors and a software update.

But before springing for that, definitely check all the sensors and sensor connectors.

 

Yes, I definitely agree with you, but what I've done should be no different than anybody else who has installed the shortened rods. My only difference is that I've then recalibrated to continue to run at "stock height", so that I have more upper range in the height sensors. Basically, they can be calibrated anywhere from +150 to +250mm. That's a 100mm range and I was around +220 originally. By installing the rods, I've simply raised the default position where the sensor arms sit by a bit, so now they are sitting around +175mm.


I could, but then I would not be riding at the stock height. If I calibrated them lower with the same rods, then the suspension would actually be lower.

@LR Techniker, thanks for the info. That's at least somewhat reassuring on the comm faults. I'll take a look into the service bulletins and definitely go reexamine the suspension sometime this week and report back to both of you.

 

I'm just not following you, cmb6s....the sensors can only be calibrated through a particular range, regardless of the rods. Beyond that you are going to get "out of range" faults. So anything you want to do (and are doing now with the short rods) should be viable using the IIDTool and the standard rods. Advantage is that it's potentially less confusing to the EAS.

 

Houm_wa,

I don't know what the best way to explain it is, but the actual height of the height sensor arm controls the height of the entire car from a zero reference point... this zero reference point is done through the calibration.

All I've done is change the zero reference point so that the arm is at a lower spot now in it's working range - done through the use of the short rods and a recalibration. This has allowed me to run at the 465mm stock height in the front and 485mm stock height in the rear while giving me about 75mm of upwards "play" with the IID tool instead of the 31mm I had before.

Anyway, I went out yesterday and pulled each rod off and rotated the sensor arms to make sure they moved freely. I then checked the electrical connectors to make sure they were seated firmly. Then, I noticed that two of the wheels seemed to be off by about 0.75", so I put the car in tight tolerance mode, did a recalibration, set it back to normal mode, and did the "re-enable EAS function" just in case. I also removed fuse 23 or whatever the main one is and reseated it. Then, I went out for a drive... no errors this time! I also have not received an error yet today, so I'm hopeful that this may have solved the problem. I will post in a few days and let you know how it turns out.

 

Yes please keep us posted. Oh, and I think I understand what you're saying with the shorter rods (I ran them myself for a while) I just think that you can accomplish the same thing with two separate settings in the IIDTool. ...and that would be simpler.

 

So, I think I'm doing a terrible job of explaining this and since I'm an engineer, I probably communicate better with pictures.

If you look at the top picture in the attached pdf, this is what a "normal" LR3 would look like ideally. The sensor arm has 100mm of travel for calibration purposes, and ideally, it would be calibrated in the middle. Now, the IID tool can only raise or lower the suspension within the constraints of the sensor calibration range. For example, it could not raise the suspension by 100mm here because you only have 50mm until you hit the calibration limit.

What this would look like in the tool menu is that the calibration would read at 200mm for that particular wheel (with the ride height at 466mm for a front wheel) and then when you go in to adjust the height in order to save your setting (we're not talking calibration now), you would only be able to adjust it up or down by 50mm.

Now, if you look at the bottom picture, this is what the sensor looks like with shortened rods... picture the rods sticking up from the end of the sensor arm. As you can see, the sensor arm is higher than before. Let's assume that it is at a value of "175" within this 150-250mm window. This means that your calibration value would be 175mm (you would be at the exact same ride height as before - 466mm), but you could now adjust your height by 75mm upwards or 25mm downwards via the tool and save your settings into the 3 custom slots. This is what I did for myself. Custom 1 = standard street height, Custom 2 = +75mm now for off road, and Custom 3 = -25mm for my in-laws getting in and out of the car.

So, I hope that explains why I could just do it with the IID tool alone. On a related note, I finally got to take the LR3 out to an off road park this past weekend and run with 4 other Jeep JKs, all on 35" tire and with 2-4" of lift, and one FJ80. No suspension errors other than an "compressor overheat" warning towards the end... probably user error from too much raising/lowering. I have to say that I was completely in awe of what this truck is capable of doing. The hills that I was climbing/descending and the muddy ruts that I was getting into/out of even while dragging my belly was utterly amazing. I don't think I could do it justice by describing it because people would probably think I was exaggerating, but I think the ONLY limitation of this vehicle is the ground clearance. Oh, and I learned that a sump guard is an absolute MUST - glad I got mine. Now, I just need some sliders.