A control module is like a small computer in your car that helps control different parts of the vehicle. If something goes wrong, it can affect how the car runs.
SJ Auto Solutions is a business that helps people with car electronics. They can clone control modules, which are important parts of a car's computer system.
Air suspension systems are a type of vehicle suspension that uses air instead of metal springs. This helps the car ride smoother and can be adjusted to make the car higher or lower.
Stellantis is a big car company that makes many different brands of vehicles, like Jeep and Dodge. They were created when two car companies joined together.
The Dodge Ram is a big truck that people often use for work or to carry heavy things. It's known for being strong and comfortable, which makes it a favorite for many drivers.
The Jeep Grand Cherokee is a popular SUV that can handle rough terrain and is comfortable for everyday driving. It's known for having a lot of space inside and good technology features.
The Volvo XC60 is a fancy SUV that is designed to keep you and your family safe while driving. It looks nice inside and out, and it's a good option if you want a comfortable ride with lots of safety features.
The GMC Yukon is a large SUV that has a lot of room for passengers and cargo. It's good for families and can tow heavy things, making it versatile for different needs.
An air tank reservoir is like a storage tank for air in a car's suspension system. It helps keep the car at the right height and can adjust based on how heavy the car is loaded.
Nitrogen is a type of gas that is used to fill tires and other parts of cars. It helps keep things from rusting and works better than regular air in some cases.
A pre-charged system is a part that is already filled with the right gas or fluid when you buy it. This means you don't have to do anything extra to get it working properly right away.
A compressor is a part that helps to push air or gas through a system, like in car air conditioning. It makes the air cooler by compressing the gas inside it.
Continental is a big company that makes parts for cars, like tires and suspension systems. They are known for making high-quality products that help cars run better.
The air charge is the air that goes into the engine to help it run. If there's a problem with this air getting in, the engine might not work properly. Finding leaks in the air system is important to fix the issue.
J 2534 is a set of rules that helps mechanics connect tools to a car's computer. This allows them to fix or update the car's software, which is important for making sure everything works correctly.
O rings are rubber rings that help seal connections in cars to stop air or fluid from leaking out. They are important for keeping systems working properly.
A regulator is a part that helps control how much pressure is in a system, making sure it doesn't get too high or too low. It keeps everything working safely and properly.
An air spring is a part of a car's suspension that uses air to help support the weight of the car and make the ride smoother. It can adjust how high or low the car sits based on how much air is inside.
An aluminum tank is a container made of a lightweight metal called aluminum. It's used in cars to hold things like fuel or air because it doesn't rust easily and is lighter than other materials.
LIVE
Welcome to the Automotive Diagnostic Podcast.
We're going to explore ways to sharpen our diagnostic skills, find learning resources, and hear from
experts in the automotive field.
Hey, have you ever been faced with the challenge of sourcing, installing, and programming a used
control module in a vehicle?
I know a lot of us have.
It seems to be happening more and more often today with the volume of control modules
on vehicles, the cost of some new ones, or even the availability of new control modules
in some cases used may be the only option.
So what do you do here?
I strongly recommend checking out SJ Auto Solutions and Tommy Oliva.
Tommy offers a cloning service for used control modules to make these things plug and play
for the vehicle that you're working on.
In a lot of cases, he is also able to source the control modules if you're unable to locate
one for the vehicle that you're working on.
But once you get connected with Tommy, he's going to offer fantastic support from
Start to Finish to make sure that that control module is going to work in your application.
He's also got tech support that he offers through his website, along with some free resources
there as well on information about used control module programming.
So make sure to check out SJ Auto Solutions.
I can't recommend that enough.
Hey, what's going on?
Automotive World.
Welcome to another episode of the Automotive Diagnostic Podcast.
My name is Sean Tipping.
I'll be your host once again for this week's episode.
Thank you so much for joining me.
This week on the show, I'm going to be talking about air suspension systems, specifically
the nitrogen-filled systems that we see primarily on the Stellantis Jeep Ram Dodge Chrysler
platforms.
So you've probably seen these in the Jeep Grand Cherokees.
The most common, at least that we're in touch with out in the field is those Grand Cherokees,
or they've had it the longest, I should say.
Also the Dodge Rams have it in some of their applications.
We do see it in a few other vehicles.
And we also see it in vehicles outside of the Stellantis platform with newer applications.
We recently had a 21 GMC Yukon that had the system and a Volvo, I think it was XC60.
Some sort of SUV platform for a Volvo had a very similar air system.
Now what these all had in common was there is an air tank reservoir to the system, which
is not common with the traditional air systems, or maybe they had one, but it was not this
aluminum style with a fill fitting that you see on, again, the Stellantis platforms and
these newer applications.
And these systems are filled with nitrogen from the factory.
And if you empty the system severely or there's a major leak or component replacement, according
to service information, you're supposed to fill them back up with nitrogen in order
to properly service the system.
This is to keep humid air from the atmosphere from entering and preventing any ice or internal
corrosion of the components.
That's the idea.
The other part of it is with a pre-charged system, which is what this is, right?
We have almost 200 PSI of pressure in these air reservoirs and in the springs at any
given time.
It can quickly fill the system because we have pressure on demand rather than having
to build it with the compressor itself, right?
And that's something to understand about these systems is, yes, we do have a air compressor
that's built into the system, but the job of the compressor is not to build the pressure
that's needed to raise or lower the vehicle, mostly raise the vehicle, but more so to
move pressure from one spot to another or to assist in the moving of pressure from
one spot to another.
Just to kind of push the air through the system, if you will, it is not designed to build
the pressure.
So you probably have seen one of these vehicles come in where it's got codes for low air
mass, right?
The charge is low.
And yes, it has a compressor.
Yes, the compressor will run, but it's not able to build that pressure back up
in the system.
You're going to have to have the tank and the connecting equipment in order to
fill that.
That's kind of what I wanted to talk about today on the show is if you're seeing
these vehicles come through your shop, they've got codes, they've got issues,
maybe you're replacing components.
It's actually not that bad to get set up to perform the service on these
vehicles.
And again, you get set up for the Chrysler systems.
You can transfer this over to these other systems that seem to have a very
similar air suspension setup.
Now I did a little bit of digging, not a ton, but it looks like
Continental is the manufacturer that makes the equipment for all of these
air systems.
Now they're going to have their nuances and their differences, but what I will
say is spending some time on this 21 Yukon.
And we had it, we had a challenge with this one, and I'll share what that
is exactly.
Maybe it's not a unique situation, but it was definitely strange at the time.
The process for filling the system, although the scan tool interface is
different, it definitely mirrors how you were filling the system with
a Dodge Jeep Ram system.
So again, not exactly the same scan tool interface is different, but you can see
the overlap.
And if you're set up for one physically with the gauges,
the tank, the hose, the quick disconnect, it works on these other systems.
And this is just a 134A fitting.
So you could go buy a quick coupler for the low side of a
134A system and you'll have the fitting that fits on these air tank systems.
Now, Dorman does make a hose set with the quick disconnects and
everything you can just buy it.
I don't know, it's a couple of hundred dollars or something like that.
You could probably make your own hoses if you wanted to go to a hardware
store and figure this out and then go to your local supplier for like
welding equipment and you can buy a tank of nitrogen, put a gauge set on the top,
hook up the hoses, get your quick disconnect and then connect up to the system.
Again, check out the Dorman kit if you just want kind of a pre made,
ready to go hose set and then again, you just need a tank of nitrogen and
some gauges and then understand how to, you know, work the regulator on
the gauge set, but it's not terribly complicated.
If you work in a shop, you know, you're probably familiar with
Oxyacetylene and so although it's not exactly the same, it's, it's the same
idea with the regulator and gauges and you can figure it out.
So what I'm saying there is it's not terribly expensive to get set up to do this.
You may already have the scan tool capability and you can do this.
Let's come back to the scan tool thing.
You can maybe do this with aftermarket scan tools, but I have had issues,
but you might already be set up with scan tool capability to do so.
And then you just need the physical component in order to charge the system.
And you can get set up for this for less than three, four hundred dollars
and you could be ready to go.
And you can charge that for one job, in my opinion, um, or make that
up in two jobs at the very least and then the equipment is paid for.
So if you're seeing these vehicles come through your shop and you know,
you're servicing them, you're doing the suspension work or even just
diagnosing like we do, we don't actually do the suspension work ourselves,
but we get shops calling us saying, Hey, you know, we either have
this code for this air suspension system or we replace this component on
this air suspension system and now, you know, it's, it's bellied out.
It's low and it won't go back up.
The compressor won't run this code.
So then we come out and we'll charge it and then we, and then we charge
for the charge, right?
Um, and it, we don't do it every day, but it's a nice little
add on service and we kept running into scenarios where, you know,
we come out, we diagnose and say, yep, it needs an air charge.
And then you're probably going to have to find the leak, right?
That's the other thing.
Um, this episode is brought to you by L one automotive training and Keith
Perkins.
If you're looking for education on module programming, J 25 34 E
prom work, key and immobilizer, electrical diagnostics or drive
ability diagnostics, Keith has a website, L one training.com that's
got over 60 hours of training videos on all those subjects and more.
When I first started out doing mobile, I utilized Keith's videos on
module programming and J 25 34 in order to get my head wrapped around
what I would need for the tooling, the computers, the software
setups, you know, what kind of obstacles I would be up against when
I'm out there programming modules on cars and it was a huge benefit to me.
And I continue to use the training videos, um, that he has on his website.
So I strongly recommend checking out L one training.com.
The link is in the show notes.
These systems are prone to leaks just like any other air suspension system is.
Um, it seems to happen a lot at the fittings, especially on the
rams. If you have a ram that has a low air mass for the air suspension system,
go to where you fill it, which is above the frame rail on the right rear of the
vehicle, pull out the inner fender liner. You'll see two ports.
Actually, you can fill the system from either port,
but almost guaranteed if those haven't been changed,
one of the O rings on the fittings is going to be leaking.
You just spray it with soapy water when there's a little bit of pressure
in the system and then you can see the bubbles coming out.
Um, and then you can actually just change those fittings and the O rings.
And then you're good to go.
Now, not saying it can't leave from other places. Of course,
the air springs themselves can be the source of a leak,
but that's a very common one on the rams and the place to take a look for.
So, um, again, where we were running into this as we come in and we
diagnose, yep, it's low on air mass and then you're going to have to
get it to the dealer or find a way to get it charged.
And then you're going to have to, you know, figure out why it was low.
And so we kind of just leave it open ended.
We really didn't give them much of a conclusion at that point.
Now we can offer to charge it up and then, you know,
decide with them. Do you guys want to spray it down and try to find a leak? Um,
generally I kind of push the shop towards, you know, that rather than us. Um,
but sometimes we'll do that, you know, grab some soapy water and figure out
again, there's common points for leaks. Um,
and then sometimes we're just coming in and doing the charge after they've
done the repair on the system.
And that's where we got involved with the Yukon and the Volvo, same things.
Um, when it's completely empty or empty
below a certain point,
that compressor is not able to recharge that system up to, you know,
the 175 to 200 PSI that it needs.
You need to put that in there from an external tank.
So when you're doing this, the way that is going to work is you're going to
take your tank, you're going to set your regulator to the pressure and you're
going to have to look in service information because different applications will
have different pressures that it shoots for. Um, again,
175 that's pretty common for the Jeeps. I had a newer Jeep,
a wagon year that was over 200 as the set point.
I want to say the Yukon was over 200 as the set point. Um,
so you're going to have to adjust your regulator to whatever the set point
is for that particular vehicle.
You can usually find that within service information.
And then you're going to connect up and you're going to fill the tank to that
pressure. Now, I will warn you here,
you can go higher on your regulator on your gauge setup. Like, right?
You can dial that up to 400 PSI if you want,
and you can put that into the air tank if you want,
but eventually you're going to go beyond the safety point.
And even if you don't, here's what can happen.
You fill that tank up to 400 PSI, right?
Cause you weren't paying attention to where your regulator was.
When the system then goes to move that pressure from the tank to the
air spring,
you can pop a line right off of that air spring or pop a hole in the air
spring. Um, it's usually the line that will actually bust off of it. Um,
I've seen that happen and that's when you have this,
the pressure set too high and it's an aluminum tank.
So it'll hold that in the car.
But then when you go to move it to an air spring,
that's when you're going to have problems.
So you can definitely overcharge these and cause damage to the system.
So pay attention to what the set point is for that vehicle so that you don't put
too much pressure into that reservoir.
But what you're doing is you're filling the reservoir with the set point of
pressure.
And then you're going to use the scan tool to fill each air spring,
or maybe just the air spring that was replaced,
but generally speaking,
you're going to do a fill for each spring individually.
Depending on the application,
it may be a full fill or a short fill option.
And then you can decide, okay, is this thing completely empty? Um,
or is it only partially low? Uh,
you can play around with that depending on the scenario that you have,
but this is a scan tool function that is now taking the pressure from the
reservoir and it is going to move it to the spring of your choosing.
Now, once you've fully filled up each air spring or the spring that you're
after, then what I will do at that point is one of two things.
I will either run an air mass check,
and this is specifically with the Chrysler system.
And what that does is the actual air suspension control module will
look at the pressures in the springs and in the reservoir and calculate it.
Basically it's a pressure to volume ratio and give
you an okay, a too low or too high after you run that air mass
check. And so then you can tell from that is the system full enough,
right? Because when you fill the reservoir with your external tank,
you're just filling that reservoir.
The system has a valving that closes it off to the air springs until it's
triggered by the control module. And again,
the compressor is there to assist pressures from moving from one spot to
another. But really it's the valve block that's going to move it from one
particular area to the nut to the next, right?
And so after you've taken the pressure from the reservoir and gone into
one of the air springs or all of the air springs,
that pressure in the reservoir is going to drop. Okay.
So then running that air mass check will give you that total like,
Hey, it needs more air or it's good or it's got too much.
That's possible too. And then I will add more using the tank, right?
It'll open up the valve on the tank,
put some more into the reservoir,
and then I will run the air mass check until it comes back as okay. Now,
if you overfill it,
there is a vent method that you can use with the scan tool as well to release
some of the pressure. So that's an option if you go too high,
but running that air mass check throughout the process really is
important. I'll do, I'll fill the springs, I'll run the air mass,
I'll adjust if needed, I'll run the air mass again. And then once it's in
that okay range, I filled all the springs, then I'm good to go, you know,
and obviously you can check for leaks if you, if you want to as well,
but that's the actual fill process that we go through. Now,
I do want to point something out here on the scan tool part of it.
I have had the best luck or I should say I've had really bad luck using
aftermarket tooling for this for some reason. And,
and this extends past just a Stellantis platform.
Obviously with the Volvo,
I don't even think I had much options for anything on the Volvo outside of using
Vita. It was newer one, but on the GM,
I couldn't do anything on this with aftermarket scan tools.
Now I tried Auto on top, maybe there's another one out there that does it,
but I ended up using GDS 2 and it was the only effective tool.
And even then it was not user friendly.
It is a very difficult system to get the hang of.
It's not intuitive in my opinion and I had to make a lot of notes on it.
So if I go back to it,
at least I understand what's happening and the process that you want to go
through. I think Chrysler is a little bit easier to work through,
but even Chrysler can be kind of difficult to work through the
processes. And again, using an aftermarket tool,
especially on the newer Chrysler stuff just did not work for me at all.
I had to use Y-Tec. So to sum that part of it up,
my suggestion is if you're going to get into this and you're going to try to run
these fill procedures and check procedures on the system,
use the factory tooling.
It seems to be the best to interact with these air suspension control modules.
Okay. Now, what if you have problems with the system?
Now number one, the compressors can fail.
And usually what happens is they've overheated for moving air back and
forth too many times and you'll hear the compressor running,
but it's not doing what it's supposed to.
It's a pretty common failure to have a compressor go out of one of these systems.
So that's just a replacement and yeah,
you can charge it up and check the air mass as well.
But I want to talk about another problem with these systems that I've seen
twice now. One was on a Jeep and one was actually on the Yukon that I was
referencing. So these air springs that are
installed on the vehicle, right? And they're exactly that.
It's just a, it's a big strut like assembly with a boot that is going to hold
the air pressure.
And then there is a valve on the top that connects it to a line that goes to the
valve block and compressor and the tank of the system. Okay.
So that's how air gets to the air springs,
but there is a valve that screws into the top of the air spring that has a
check valve within it. Okay.
Now the purpose of this check valve is if you take the line off of the air spring,
this check valve will seat and it will allow you to take the air spring out and
still have air in it.
It's not going to completely evacuate all of the air within the air spring.
Okay. So this is a one way check valve that allows air into the air spring,
but not out of the air spring. Okay. We might say, well,
how do you lower it when you thread the line into this
valve, right? So the line that threat that actually goes into the top of it to
feed it air, if, and this is a big if the line is seated properly,
it displaces the check valve, right?
So when the line is attached to the air spring,
the line itself basically pushes down the check valve.
So then it is a two way there is, there's no more valve, essentially.
You can put air into the spring and air can come out of the spring,
but only into the line. And then as soon as you unthread the line,
pull it out, that check valve seats again.
So what there's a TSB on this or star case on this,
that when the line gets pushed up into the fitting,
it will actually not displace this check valve.
And the problem is is air can go into the spring, but it'll never come out.
And so when you're doing your fill process or your, um, um,
level calibration, which is one thing I didn't mention,
you can do a level calibration as well with the factory tooling.
It will put air into that spring,
but it'll never be able to release it because that, uh,
check valve isn't displaced.
And the way this happens is the fitting that you actually use to tighten up the
line to the air spring, it has a collar on it,
kind of like a old compression fitting. Um,
it's like a brass collar and it can slide down on that
line and it makes it so the line doesn't actually displace the check valve.
If you're not understanding that from the audio,
take a look, just search for the, uh, the star case.
Maybe I'll try to find it and put a link in the show notes so that you can
visually see it. Once you see it, you understand it.
But if you don't know that's a thing,
you don't know that's possible.
And that was me on the first time I dealt with this on a Jeep Wagon year
is the right rear corner was just like way up there.
And this thing had been, this was like a rebuild auction car.
And we had, they had completely, um,
changed the connector at the air suspension control module and like butt
connector, um, wired up every single wire to it.
And we were really wondering if there was some weird issue,
whereas sending air to the wrong spot.
We looked at the, uh, valve assembly to make sure all the lines were put
into the crack place.
And it just ended up being that the line had been pushed up to the point
where it wasn't displacing that check valve.
So this is a really important thing. And again, they have a star case on it.
So I'm not the first one to deal with it,
but I saw it again in a different way on this Yukon.
So this Yukon,
they had replaced the air spring with an aftermarket assembly.
And when they did this, the aftermarket assembly,
if you imagine the left front of the vehicle where this was,
and it sits into the top of the spring sits into a
mount that's on the frame rail, that kind of the metal portion of the
frame rail kind of comes over the top of the air spring.
And then there's a hole and then the line comes in the middle.
And that's where that valve is.
And this valve is the same setup as on the Jeeps, right?
Check valve goes into the top of the air spring, has a, uh,
check valve that the line is meant to do, displace.
Well, the aftermarket spring sat down further
within this, uh, you know, underneath the frame.
And so you couldn't get to this check valve when the
air spring was installed, right?
And so you have to tighten this up with a wrench.
It's got a hex on it that you thread it down and you tighten it up.
Technician couldn't get to that.
So what they did to make this work is they took another check valve and put
it on top of that check valve, right?
So they screwed one into the other and then it protruded up enough above
the frame rail so that they could tighten it with a wrench.
Hey, great.
I mean, we modified it, we made it work.
Well, the problem is one check valve on top of another doesn't work.
And so the top check valve, but basically both of them were
allowing air in, but that bottom check valve wasn't displaced at all.
And so we had the same situation.
Air could go into that air spring, but it could not come out.
And that took me a really long time to find out because
I didn't know that they put two on there.
And the GM interface with the scan tool was even more challenging to use.
Um, I spent hours on that car trying to figure out what was going on.
And then finally talking with the technician and then looking at it.
Cause you couldn't see that there was two.
If you just looked at it from the top of the vehicle.
Um, but then I'm talking to him.
He's like, yeah, I just put another one on top so I could get the line on.
And I'm like, okay, that's what we're dealing with.
And as soon as we got that all figured out, I think they ended up
getting a OE, um, air spring on that one.
Uh, that was the only thing that ended up working for that car.
But anyways, I just wanted to share that on the air suspension systems.
Um, they can be tricky to work with until you understand them fully.
Um, again, I'll try to put a little bit of information into the show notes
here and hopefully the information in this episode helped as well.
But, uh, I'd like to thank everybody for listening and let's get out there.
Start fixing the world one car at a time.
About this episode
Exploring the intricacies of nitrogen air suspension systems, this episode dives into servicing techniques for vehicles like the Jeep Grand Cherokee and Dodge Ram. Host Sean Tipping discusses the importance of using nitrogen to prevent moisture-related issues in air suspension systems, as well as the tools and methods needed for effective servicing. He also shares insights on common leak points and how to diagnose and charge these systems, making it a valuable resource for automotive professionals looking to enhance their diagnostic skills.
This week on the show I share some information on nitrogen filled air suspension systems found in Stellantis vehicles, as well as other brands such as GM & Volvo. I'll discuss the equipment, tooling, service procedures, along with some obstacles I've run into along the way.
