Air suspension not working, sporadic errors.

[ayavner]

Hey TMC brain trust,

So - this started a couple of weeks ago (before my MCU2 upgrade, maybe irrelevant but its a data point). When driving, an "air suspension adjustment unavailable" error would flash, followed by a red dummy light on the display. A note would go in the Notifications log, but it would always be historical - ie, time stamped in the past but saying "no active alerts". Anyway, intermittent and didn't really seem to affect anything so I had them look at it at the SC during my recent visit to upgrade the MCU.

The technician spent a good portion of the day troubleshooting, and was unable to find anything. My impression was if an alert is logged, there should be a corresponding source to the alert - a specific sensor or similar?

Anyway - nothing to see here, went ahead with the MCU2 upgrade.

After I got home with the newly-upgraded MCU, the car made this awful buzzing noise that in hindsight sounded exactly like a small compressor running its little heart out. So I am guessing it gave up the ghost after running that way for 6+ hours (no idea - I went to bed).

So where it sits now is I am unable to adjust the ride height - even though the picture of the car in the display moves up and down with the slider, nothing happens physically. At this time the car appears to be on its lowest setting, which means around here I can ground myself on a pebble...

I am not sure how it would have gone from irritating to inoperable in one day with the MCU upgrade being the only "change". I set up another SC call, but I am a bit irritated to have to take it all the way there for the exact thing I asked them to look at last time. Preaching to the choir I am sure.

As I write this, coincidentally, I just got invited to update to 2022.24.8 - I wonder if they are pushing that in the hopes it will help? Unlikely but we'll see!

Does anyone else have a similar experience with the adjustable suspension to share?

 

[ayavner]

Well, it's gone from bad to worse - the car is now sitting more or less completely deflated. The pictogram in the menu still moves to indicate height, but there is no corresponding compressor noise or movement. At this point, I would not likely even be able to get it on a flatbed without help from a crane. Mobile service is probably 2 weeks out, so guess I need to start picking off the obvious. At the moment I am guessing that is the fuse, and perhaps seeing if I can get a voltage across the compressor to verify that it works.

Other than that - does anyone know if there is a "service port" to allow an external compressor to help at least get the car up so it is moveable? I know where the fuse boxes are, but unsure where the other components are. It is unlikely to me that all 4 air shocks or all 4 ride height sensors would have gone bad, so it must be a common component - anyone have a diagram or sketch to help me out? TIA!!

adam

 

[ayavner]

The error screen is what I asked them to look at when I was at the service center. They said they found nothing. The above picture is how it is now, 2 days later.

 

[zoomer0056]

View attachment 851346

View attachment 851347
The error screen is what I asked them to look at when I was at the service center. They said they found nothing. The above picture is how it is now, 2 days later.

I think this time the SC can not say there's no problem! From reading this forum the past year it seems even to Tesla SC that a lot of problems are new to them. Tesla is very dynamic. The problems are very dynamic and the SC techs can't keep up. Hopefully with your S sitting so low they'll have something to look at and definitively fix. Side note: what a disaster SpaceX would be if a problem occurred and the engineers said they couldn't find any thing.

 

[ayavner]

A potential list (keeping track of my thoughts, as well as for posterity...):

Fuse box #2, F36 (10A)
Fuse box #3, relay K11?
Fuse box #4, F82 (40A) - not sure if I have this one, saw a note that "some cars" may have this...

Leaks @ all 4 struts and air lines (hard to check with soapy water with no pressure on the line, will look for holes)?
Compressor seized or burned out? pinhole in air line, per this thread?
Leaks or other crap build-up in the valve block?
Ride height sensor bad?

I *hope* I can get to most of this stuff from under the frunk liner, because there is NO getting a jack under this thing....

More to follow, but please chip in if you can point me in the direction of a system diagram. My google-fu is weak this morning, apparently...

 

[ayavner]

Ok scratch that - was looking at the wrong year model owner’s manual. We are looking at F154 and/or K112.

bingo - F154 is blown. 40A fuse, not sure if they have these at OReilly, but now to figure out WHY it blew. Most likely, that noise I reported in another thread was the compressor running all night (but why?)

 

[ayavner]

Ok so I put a spare in and it blew pretty quickly without the motor even attempting to engage. The relay seems to work ok (continuity on the coil, open across the terminals). Stuck on where to go next, but guessing best move now will be to get the system pumped up and up enough to drive to my SC appointment.

Edit: thinking the compressor must be seized, and when it attempts to move and can’t, it just out draws the fuse which does it’s job!

 

[zoomer0056]

Ok scratch that - was looking at the wrong year model owner’s manual. We are looking at F154 and/or K112.

bingo - F154 is blown. 40A fuse, not sure if they have these at OReilly, but now to figure out WHY it blew. Most likely, that noise I reported in another thread was the compressor running all night (but why?)

Awesome! You're an inspiration with how you kept with it. Now to find the cause of that blown fuse. Gotta be a short. Look for pinched or bare wire. Better this than a bad internal part of a component.

 

[ayavner]

Thanks Zoomer,

Update: having determined that the relay was good and the fuse was blown (and spare blew as well), I took a look at the reservoir.

here are the fuse and relay for reference:

And here is the reservoir:

Did a quick conversion, and 17.3 bar is about 250psi. I don’t have anything handy that would go that high, but I do have my Dewalt portable that I keep in the trunk. It is good for about 160psi. I hooked it up to the valve (see pic) and ran it to 160. Got in the car and pressed the brake and raised the suspension to high. It didn’t get all the way there, so I repeated that 3 times then selected standard height.

although the fuse is out so the compressor doesn’t run, the solenoid still actuates and delivers air to the manifold thence to the struts.

Black line to/from reservoir, purple line to manifold.

So far it is holding! I have disabled automatic lowering at speed, so hopefully this will last till I can either troubleshoot the compressor or get to the SC on Thursday.

this looks better!!

 

[Doanster1]

Sorry, didn’t see this thread until now. Great job troubleshooting and getting it back up vs slammed. Your compressor has seized as you suspected. It’s actually a miracle that the reservoir actually lifted the car. When my SAS saga happened, the red icon prevented the reservoir from dispensing air even though it was filled and at pressure.
A few of us (@BostonBurley) went through the same issue. Search for my thread “eas_w007 error”. I swapped the compressor multiple times with an aftermarket unit that would burn out after a few wks so ended up biting the bullet and having the SC replace. Rock solid ever since. So if you go DIY route, I’d buy a factory unit (new or used, but genuine). Even though the compressor is shared with Audis, Jeep Geand Cherokees, etc., it didn’t work out so well for me.

 

[ayavner]

Thanks, @Doanster1 - that will save me from going down an unfruitful path. So in this case, I did a hard reboot of the car to get rid of the red icon, and that seemed to allow the reservoir to distribute air (after enough refills). I am guessing there is a pressure sensor along with the ride height sensors - I was never able to find a diagram of the system, but I think I have a basic flow down in my head.

Any thoughts on why it was seized? I imagine it is because it ran all night after my SC visit - but why was it tripping the error to begin with? (Same as yours). Hard to believe they didn't find anything when I brought it in, and even harder to believe that it finally ran itself to destruction AFTER the visit. Also, with a discrete error cod (EAS_w007), there are typically going to be some conditions that toggle it to set... what are those conditions? They couldn't tell me. Since I haven't found any leaks, and the car is still holding overnight, I can only imagine that the compressor was just not building enough pressure to fill that reservoir in a timely fashion.

I actually did see your other thread, now I'll go back and reread it with some context of my own behind it. I hope they are able to fix it this week, I can't keep pumping it up with the Dewalt

Does anyone know where the measurement of the height is taken? I am not sure I got that right, but I expect it will set itself to the right point with a bit of driving. More to come!

 

[Gtech]

Thanks, @Doanster1 - that will save me from going down an unfruitful path. So in this case, I did a hard reboot of the car to get rid of the red icon, and that seemed to allow the reservoir to distribute air (after enough refills). I am guessing there is a pressure sensor along with the ride height sensors - I was never able to find a diagram of the system, but I think I have a basic flow down in my head.

Any thoughts on why it was seized? I imagine it is because it ran all night after my SC visit - but why was it tripping the error to begin with? (Same as yours). Hard to believe they didn't find anything when I brought it in, and even harder to believe that it finally ran itself to destruction AFTER the visit. Also, with a discrete error cod (EAS_w007), there are typically going to be some conditions that toggle it to set... what are those conditions? They couldn't tell me. Since I haven't found any leaks, and the car is still holding overnight, I can only imagine that the compressor was just not building enough pressure to fill that reservoir in a timely fashion.

I actually did see your other thread, now I'll go back and reread it with some context of my own behind it. I hope they are able to fix it this week, I can't keep pumping it up with the Dewalt

Does anyone know where the measurement of the height is taken? I am not sure I got that right, but I expect it will set itself to the right point with a bit of driving. More to come!

Height measurement is done on all four corners (sensors on upper control arms)
Main pressure sensor is inside solenoid valve block.

I believe I posted some SAS diagrams along this forum but not sure which topic but you can always check Tesla's wiring diagrams and repair instructions

 

[Doanster1]

Here’s the diagram courtesy of @Gtech
Yes, there’s a pressure sensor that the SAS ECU/computer reads/monitors. Like previously mentioned, each corner has a height sensor.
The reservoir does not run out of air very easily. The compressor being seized/shorted is what’s blowing the fuse and throwing the red icon. In my case, the fuse is under the air filter box so not easily accessible. Replacing it got rid of the icon for a split second, but blew again due to over current from the compressor so the reservoir never got a chance to lift the car.

 

[ayavner]

Thank you @Doanster1 !!

This confirms my approach somewhat -- I'll make sure and cover all of my steps with the service tech when I get there on Friday

 

[Doanster1]

Thank you @Doanster1 !!

This confirms my approach somewhat -- I'll make sure and cover all of my steps with the service tech when I get there on Friday

Be prepared for sticker shock. They will want to replace the compressor as well as the valve block. Don’t recall anyone ever reporting they were willing to replace just the compressor. Good luck and keep us posted.

 

[Gtech]

I find it interesting that normally the compressor is needed to raise and lower the car (it harvests air pressure from the struts to the compressor back into the reservoir and vise versa, that's where the reversing solenoids on the compressor are for, it can push or pull air pressure to the struts) and you actually got the car raised with a blown fuse for the compressor without manually manipulating the solenoid valve block

 

[BostonBurley]

I find it interesting that normally the compressor is needed to raise and lower the car (it harvests air pressure from the struts to the compressor back into the reservoir and vise versa, that's where the reversing solenoids on the compressor are for, it can push or pull air pressure to the struts) and you actually got the car raised with a blown fuse for the compressor without manually manipulating the solenoid valve block

I did the same thing @ayavner did, but I used my mountain bike suspension pump. Achieving 160psi with that little thing took like 300 pumps. Anyway, it raised the car a smidge after a hard reset, but just errored out.
I never had a bad relay or blown fuse, but otherwise I’m with y’all. Tried a cheapo eBay compressor, not bad, but didn’t fix anything. Tried a used oem compressor, literally identical. Same results. But I figured it would run itself into the ground and after a while it quieted considerably and the SAS works correctly.
However, I’m fairly certain that in the course of time of doing this, the rear subframe has once again broken. Might just let it be broken and tear up my new component bushings for awhile. Sick of all the money and effort… haha, but it really does make me sick in the head. Would gladly try to fix it all with a garage instead of an apartment carport. I digress.

 

[ayavner]

I tested my relay off the car, and it appears good (contacts normally open, and close with 12V across the coil) - but it is not above suspicion.

@Gtech - do you know if the relay is what powers the compressor, or does the compressor get its on/off signals from the ECM? Wondering if perhaps at some point the relay got stuck closed and maybe that is what started this whole mess (with the eventual destruction of the compressor).

Remember when this started a few weeks ago, it was just that I was getting the red icon with no ill physical effects that I could observe, and the Service Center couldn't even identify what was wrong. I guess the silver lining is now they should have no trouble seeing there is an issue

 

[Doanster1]

As I’ve discussed with @Gtech multiple times… if Toolbox was readily available and affordable (even for a neutered version allowing reading/clearing codes), we’d all be much better off. I do believe the SC that the litany of stored EAS codes I had threw the system off even after I successfully swapped in a working compressor. After they cleared the codes, the system worked, albeit for the aforementioned short few weeks.

 

[Doanster1]

I tested my relay off the car, and it appears good (contacts normally open, and close with 12V across the coil) - but it is not above suspicion.

@Gtech - do you know if the relay is what powers the compressor, or does the compressor get its on/off signals from the ECM? Wondering if perhaps at some point the relay got stuck closed and maybe that is what started this whole mess (with the eventual destruction of the compressor).

Remember when this started a few weeks ago, it was just that I was getting the red icon with no ill physical effects that I could observe, and the Service Center couldn't even identify what was wrong. I guess the silver lining is now they should have no trouble seeing there is an issue

The SAS ECU is calling the shots. If you’ve already bench tested the relay and it clicks when you applied power, it’s good.
Easy final test - K15 and K16 are the same relay as K11 so just swap them.