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Discussion Starter #1 (Edited)
I want to start a thread around the factory Air Suspension because it appears many have had issues with it in cold weather, including myself. This is my 3rd Winter and I experienced the blown fuse first and then situations when the suspension will not operate. I have an extended warranty and brought it to the dealer and their answer is that they will just replace the Air Supply Unit (ASU)

There doesn't appear to be a lot of technical information on it and a lot of misinformation posted on it so here goes....

I have a Foxwell Tool with the Chrysler specific add-on so I can access the Air Suspension module to view codes, metrics, and run tests. This is what I understand so far, and if anyone wants to correct any items please feel free to make suggestions:

1.. First and foremost. The Air Ride Suspension is designed as a sealed nitrogen filled system and does not have the capability to bring in outside air unless commanded with the fill port and procedure. It is manufactured by Continental Automotive.
2.. The system does have the ability to vent to atmosphere with the vent located in the passenger rear taillight area. It is unclear on what commands this to take place but there are test procedures to vent each bag to atmosphere and I think if your ASU is locked up and you hit transport mode you vent to atmosphere.
3.. There are 2 tanks (Reservoir High/Low), the ASU, Air Suspension Control Module (ASCM), Bags, and Level Sensors.
4.. The ASU contains the air dryer, compressor, exhaust valve, valve block, pressure sensor, and temperature sensor.
5.. There have been numerous revisions to the ASU to deal with cold temperature issues. The latest was in late 2016 and involved changes to components to prevent lockup of the compressor head due to dissimilar expansion and contraction of materials. (My Dealer tells me there is a new upcoming revision to the control module to fix the fuse blowing issues)
6.. The unit needs to do a Air Mass Calculation to bring it into operation anytime you utilize testing procedures. (Plant Mode). This Air Mass Calculation is needed because the nitrogen is dispersed through the components at any point in time so it needs to get a true calculation of how much nitrogen the system has in the system. It does this by checking the pressure of each bag, tank, and the reservoir. The reservoir is charged to 175 PSI when new and again, it has the ability to sustain many vents to atmosphere before it will reach the point where the Air Mass is not enough for the system to operate.

From an issue perspective the system appears to have 2 levels of codes:

Yellow - "Service Air Suspension" or "Ride Height Not Permitted" - The system has pressure but the ASU has a code or the ASU is responding but is not able to execute function. It will be yellow the air bags are inflated and within a certain level or height spec.
Red - "Service Air Suspension Now" - The ASU is not responding at all, the system has low or no pressure, one or more bags has no pressure or below normal ride height or differential.

When looking at issues, they appear to be broken down into:

System Leak - There is a leak either to Tank or Atmosphere.
ASU or ASCM Failure or Frozen - The ASU or ASCM is not responding or unable to complete command.

Basically if your truck is on the bump stops, you have a leak. If the leak is to the atmosphere, your truck will at some point in time run out of nitrogen in the reservoir and you will get a Red Code. If the truck is more or less level and not in entry mode, you will get a yellow code. There are circumstances though that can result in your tuck lowering slightly after huge temp swings because the truck has a timer when shutoff to where it will level the truck. Once leveled, it will not run the ASU to level it until you start the truck.

If anyone wants to add anything, please feel free.

Cheers,
 

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Excellent write up. Thanks for the information. My Truck had no problems the first two winters (one of which was really cold), but now nothing but issues. It was working fine yesterday - but today it is back on the bump stops. The Truck thinks it is Level according to the EVIC and the buttons, however it is not. Selecting Off Road 1 - the Truck indicates it is raising, but nothing happens (no compressor noises either).

Errors I had in the Truck this morning: "Air Suspension is Cooling Down" (when I tried Off Road 1 the 1st time). Then Service Air Suspension Immediately later on the drive.

Took about 15 minutes to get to work - with the Truck indicating that it was "raising" the entire time, but not really doing anything.

My Compressor was replaced 2 weeks ago, as they discovered a leak.
 

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I should indicate the first problem I had with the Air Suspension was in Summer - ended up being a corroded Left Front Sensor. They cleaned it up, instead of replacing. I still think part of my problems are a Sensor issue.
 

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A very nice writeup and thanks for taking the time to do it.

I would suggest that the following sentence from your writeup be modified from

ASU Failure or Frozen - The ASU is not responding or unable to complete command.

to

ASU or ASCM Failure or Frozen - The ASU or ASCM is not responding or unable to complete command.

The reason I say this si that my 2014 had intermittent cold weather problems and it was finally resolved with assistance from FCA by a replacement of what they called the 'control module' located under the driver's seat. I presume they were referring to the ASCM in your vernacular. I still have my original compressor and it worked fine in the recent minus 32 and minus 26 deg F weather, but it was parked int he garage. However, it did spend several hours outside in those temps those 2 dAYS.
 

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Discussion Starter #5
Makes sense, done.
 

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Discussion Starter #6
One other thing I wanted to note. The fuse blowing issue in cold temps may appear to be a result of extreme electrical amperage draw on the battery that causes the pump to effectively stall due to higher than expected amperage and blow the fuse. (Voltage drop, Amperage increases?) This condition typically happens with a cold remote start and I think someone else on this forum may have narrowed into this. The dealer mentioned this to me that they thought a new firmware was coming to delay the operation of the ASU during a remote start or to drop the cabin heat elements while the pump starts in cold weather. Curious because mine blew during a remote start.

I am wondering if all or most fuse blow incidents happen with a remote start?
 

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One other thing I wanted to note. The fuse blowing issue in cold temps may appear to be a result of extreme electrical amperage draw on the battery that causes the pump to effectively stall due to higher than expected amperage and blow the fuse. (Voltage drop, Amperage increases?) This condition typically happens with a cold remote start and I think someone else on this forum may have narrowed into this. The dealer mentioned this to me that they thought a new firmware was coming to delay the operation of the ASU during a remote start or to drop the cabin heat elements while the pump starts in cold weather. Curious because mine blew during a remote start.

I am wondering if all or most fuse blow incidents happen with a remote start?
I blew 2 fuses in cold weather and I do not use remote start. That said, I don't think remote start vs local start makes any difference. In very cold weather the battery has less capacity, the glow plugs are on for a relatively long time and the starter draw is high so the battery voltage is likely below the full 14.4 volts or so when it is on idle after a startup with limited alternator output. I think the theory of added amp draw due to both somewhat reduced voltage with its increased amp draw to achieve the same hp coupled with a potential increased hp draw of the compressor due to the cold weather could be the problem. I cannot see how the remote start affects this one way or the other.

bticbw
 

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MacRam, can your tool calibrate the ride height sensors? I pulled the sensor calibrations up on AlfaOBD and 3 of mine are in the 250-270mm range and the fourth is at 30mm. I'm trying to level my truck side-to-side but I'm hesitant to jump in and start making calibration changes. Any experience here?
 

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Discussion Starter #9
MacRam, can your tool calibrate the ride height sensors? I pulled the sensor calibrations up on AlfaOBD and 3 of mine are in the 250-270mm range and the fourth is at 30mm. I'm trying to level my truck side-to-side but I'm hesitant to jump in and start making calibration changes. Any experience here?
No, mine does not appear to be able to modify those values. I have not run all of the active tests though as of yet. I ended up doing a level test that failed and basically left me with the suspension stuck in plant mode.

I tried restarting, reset ECU, etc and nothing.

This is where I learned that after any plant mode you need to do a air mass check. That put it all back in order.

All data has an All Data DIY plan for the truck for a year at $29 so o was thinking of getting it in hopes it has the items for the Air Suspension.

Sent from my SM-G950W using Tapatalk
 

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I believe mine can be adjusted through AlfaOBD and it would also be an option for those wanting an inexpensive level to the front end.

I know many with air suspension suffer from the left lean.
 

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Discussion Starter #11
I believe mine can be adjusted through AlfaOBD and it would also be an option for those wanting an inexpensive level to the front end.

I know many with air suspension suffer from the left lean.
So are you going to be our test subject?

Sent from my SM-G950W using Tapatalk
 

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I believe mine can be adjusted through AlfaOBD and it would also be an option for those wanting an inexpensive level to the front end.

I know many with air suspension suffer from the left lean.
yes, low on the left side when sitting on a level pavement but about level when driving on a normally crowned highway, unless you live where you drive on the left side of the road.
 

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Would be interested in an ODE that allows at least some access to the Air Suspension. I have Tourque App - but it shows nothing when it comes to Air Suspension - error codes, etc.
 

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Would be interested in an ODE that allows at least some access to the Air Suspension. I have Tourque App - but it shows nothing when it comes to Air Suspension - error codes, etc.
You can access the air suspension diagnostics and values with AlfaOBD. I have not messed with mine. But apparently AlfaOBD will allow you to mess with the settings and run test.
 

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I blew 2 fuses in cold weather and I do not use remote start. That said, I don't think remote start vs local start makes any difference. In very cold weather the battery has less capacity, the glow plugs are on for a relatively long time and the starter draw is high so the battery voltage is likely below the full 14.4 volts or so when it is on idle after a startup with limited alternator output. I think the theory of added amp draw due to both somewhat reduced voltage with its increased amp draw to achieve the same hp coupled with a potential increased hp draw of the compressor due to the cold weather could be the problem. I cannot see how the remote start affects this one way or the other.

bticbw
OK Stupid question, what would happen if i replaced the 40 amp fuse in the Air Suspension F5 location with a 50 amp.
 

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OK Stupid question, what would happen if i replaced the 40 amp fuse in the Air Suspension F5 location with a 50 amp.
Seems like there are a few potential outcomes depending upon what the real problem is I can surmise the following

1-Nothing bad and the system draws an extra amp or two and solves the nuisance fuse blowing with no real harm

2-Still not enough and the fuse still blows but wiring or motor not damaged.

3-Burns out the motor of the compressor and/or melts wiring either initially or eventually.

It would seem to me if this was a reliable and safe fix it would be one FCA would have issued a bulletin on.
 

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First off I would like to say great write up on how this air suspension actually works, that’s the most information I’ve seen on the system to date. I have a 2014 ram that I purchased in late 2016. I have owned it now for about 2.5 years and have had the Air Suspension fail 3 times, every winter at -25c or colder. I purchased the extended warranty so this problem hasn’t cost me a dime yet but the problem obviously hasn’t been fixed as it keeps happening. Feb. 2019 there were so many trucks at the dealership with Air Suspension problems that I couldn’t get mine in for repair for almost 2 weeks. I know of 6 people who had the Air Suspension with all the same problems, they failed every winter. These rams were of all years from 2014-2017. Needless to say everyone of them traded them off on a different brand as they were so PO at ram for selling something that doesn’t work in Canada. Having said that the dealership is no longer bringing in any vehicle with the Air Suspension. So my question is... can I some how lock the Air Suspension in off road one for the winter no matter what speed I travel so the system doesn’t have to run in cold weather? Thanks for your help.
 
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