[Phillip5690]

I have a 2012 qx56, this past weekend the rear air suspension went low to the ground. I let it sit over night and started it in the morning and it was still down. I checked the fuse and it was good.
Later on in the day it went back up but came down. Stayed down till this morning. (4 days later) I woke up started the car and took of for work and it went back up.
I’m lost at this point because it doesn’t seem like a leak because the car is maintaining its ride height now and the compressor is working fine. But at times it’s acting up and not lifting the rear and i won’t hear the compressor come on. It’s cold here in Chicago now, and today is a pretty cold day to have it lift with no issues and stay up if it were due to the cold acting up.
Anyone experience this issue?

 

[marctronixx]

its a leak.

air expands and compresses with temp. just like your tire pressure.

these posts usually show up in the winter time.

if its too cold it may be preventing the compressor from actually starting up.

put some soap on the air lines and bladder whilst the system is charged properly with air and see if you see leaks.

 

[Phillip5690]

So yea, this thing has a mind of its own.. it goes up, stays up fine for days at a time, then goes down and stays down for days. Every day temps have been different but I do understand that cold messes with air suspension. But it has been a solid 50’s here and isn’t going back up. Seems to be going up when it drops to 2’s. Also, there is no check suspension light on. ??‍♂
So annoying!!

 

[bassmadrigal]

The Check Suspension light is garbage. There are so few things it will light up for when there's obvious problems with the system. And while cold air does affect suspension because of air condensing, it is not as drastic as what sounds like happens here.

I do echo marctronixx's thought that initially it does sound like there is a leak. Soapy water can help find that. However, it could also be an electronics issue, but these are far harder to diagnose. The first thing I would check is your height sensor. If it isn't terribly expensive (I've never looked into it), it might be worth replacing it, just to simply eliminate that as a source of the problem.

 

[jrm5f2]

Sounds like your problem might be three things a bad compressor, a leak in the system, or a bad height sensor. First always check for leaks! The sensor has two functions to send a signal to inflate and another one to deflate. You can test this by removing the sensor (the one close to the compressor) while the truck is on and moving the arm up or down on the sensor itself( PLEASE make sure the parking brake is on and you take all precautions to be SAFE!). Up should kick on the compressor and down show let air out of the system. If the you move the arm up and the compressor does not kick on it may be the compressor, if there is already air in the system and you pull the arm down and nothing happens then this would indicate an issue with the sensor. If all else fails, it simply could be both. When mine failed, it was the compressor and not the senor. So to be honest it sounds like your compressor is going bad.

 

[G00fySmiley]

So yea, this thing has a mind of its own.. it goes up, stays up fine for days at a time, then goes down and stays down for days. Every day temps have been different but I do understand that cold messes with air suspension. But it has been a solid 50’s here and isn’t going back up. Seems to be going up when it drops to 2’s. Also, there is no check suspension light on. ??‍♂
So annoying!!

given that it acts normal for days then stops then stays down I would put my money on a bad ride height sensor.

 

[primoV8]

I had posted this before regarding a friend’s issue with his 08 QX56 rear suspension:

The auto-leveling rear compressor has an internal exhaust valve solenoid. The purpose of that valve is to vent air out when additional height isn’t needed; info relayed from the height adjustment arm to the auto-level ccu.

Unfortunately, that internal exhaust valve can corrode, which will lead to the rear suspension sagging because the valve randomly gets stuck open/leaking and not inflating the bags when needed.

On my friend’s previous 08 QX56; he replaced the air shocks, height sensor and his compressor would turn on. Sometimes the air leveling shocks inflated and stayed up for some time but the rear would eventually start sagging. Other times, it would inflate and immediately deflate once he would start driving. We finally had the chance to meet up and I used my diagnostic tool to check out his auto-leveling system. It immediately showed a DTC for the exhaust valve solenoid. Also, when I turned on the compressor, the motor itself sounded very weak and took awhile to inflate the rear shocks.

Once he installed a new compressor, immediately noticed the huge difference. Not only did the new compressor sound healthier, it inflated the rear shocks much faster.

If you happen to know a shop that has a diagnostic tool that does more than just read engine DTCs, have them scan the auto-leveling system to look for the exhaust valve solenoid DTC.

 

[Jobby]

Hi....where can I find OEM or preferably non OEM Air Shock Absorbers/Struts for my 2012 Infiniti QX56. Part no 56210 1LA4A and 56211 1LA4A.
The ones showing on Amazon don't appear to be correct.



 

[primoV8]

@Jobby, go to Infinitipartsdeal.com and enter your VIN to find the exact part #(s).

 

[Jobby]

@Jobby, go to Infinitipartsdeal.com and enter your VIN to find the exact part #(s).

I think because it's not a US market vehicle, the website didn't find my VIN number.

 

[primoV8]

I think because it's not a US market vehicle, the website didn't find my VIN number.

That explains why the part # on your OE rear shock absorbers doesn’t match with domestic US dealers/retailers.
If you’re ordering from the domestic US market, it would be Nissan part #E6210-1LA7A. From your pics, I can tell your Z62 also has the HBMC suspension

 

[Jobby]

That explains why the part # on your OE rear shock absorbers doesn’t match with domestic US dealers/retailers.
If you’re ordering from the domestic US market, it would be Nissan part #E6210-1LA7A. From your pics, I can tell your Z62 also has the HBMC suspension

Hi.... sorry I don't know much about internals of the vehicle. What is Z62 and HMBC 🤦

 

[primoV8]

Hi.... sorry I don't know much about internals of the vehicle. What is Z62 and HMBC 🤦

Sorry, Z62 is just the chassis code for our trucks. HBMC is an upgraded, hydraulic suspension available on the Z62s. Your pics confirm your truck has HBMC because my Z62 looks similar to first gen WA/JA60s air leveling shocks but with a bayonet mount on top.

Since your truck has HBMC, it will also require bleeding air out of the hydraulic fluid in the HBMC system.