Air suspension

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Junior Member
Nov 24, 2022
Reaction score
Ram Year
5.7 hemi
I know their are allot of post about air suspension but I cannot find anything to help me with step by step help to get my truck back on the road with alfaobd and the air suspension. Problem is my truck is sitting on the bump stops (cold weather Wisconsin) and my truck is in plant mode now and tells me it needs calibration. So does anyone know step by step procedure to help for now? I am going to order the air suspension delete next week but won't get to putting it in for around a month and would still like to drive my truck. Any help is very much appreciated.


Senior Member
Sep 8, 2017
Reaction score
Ram Year
2012 Reg Cab, 4x4
5.7 Hemi
Yes. The answer is in the service manual.

There is a very comprehensive section on the air suspension. It lists all sorts of checks, air pressures to check, voltages and so on. I read through the whole section word by word. You can get a PDF copy if you search this forum for Service Manual/s.

Air suspensions are rather simple but have a lot of parts. Not that many compared to an engine, just parts most people don't deal with everyday. In concept it's rather simple: You have a compressor, plastic air tubes which go to -> shocks with air bags, some 'level' sensors (rheostats essentially) that tell the 'computer' what the vehicle height currently is, ..and air solenoids to allow or bleed-off air into the air shocks as necessary to meet the satisfaction of the level sensors. I'm leaving off the electronic module, check valves, air filters, and a few other components, but that's the basic concept.

What I've found working on a few different types of air systems in the past, is most things haven't changed much from the early 90's. Just a little more electronics and integration with the vehicle computer. Nearly all the problems I used to see on older air suspension systems was with hose leaks, air level sensors, and solenoids at the struts. Shops used to charge customer $1,200 for new struts when the only problem was a $25 solenoid! Now the struts themselves can go bad, but aren't usually the case. However, in WI, you can have rust which tends to build up on the metal strut tube UNDERNEATH the air bag bladder (where you can't see & doesn't dry out very well...and sharp rust flakes can wear a pinhole in the bladder as the bladder constantly moves up/down over the rust flakes). Esp in the winter where a bladder can get cold-stressed too. When the bladder develops a leak obviously it won't hold air. Sometimes the leak is small. Sometimes the leak can close itself off (stay momentarily sealed) depending on the location of the leak. In more temperate parts of the country this isn't an issue at all. But maybe small stones get thrown up (captured) between the bladder and the shock tube.

Air shocks can be pressure tested and replaced (lots of 'clean' used ones avail). Level sensors flake out a lot, and/or their connectors get corroded or wires corrode. If a level sensor comes unhooked due to some ice that got kicked up and knocked the extension lever off (or broke it), the vehicle doesn't exactly know where 'home' or level is. And it can't find level. Sensor arms can be snapped back in place, or replaced pretty reasonably. Compressors, everybody (and service shops) jump to as the immediate culprit. It's (and it's solenoid pack) are kind of the 'black box' of an air system. It's easy to blame the computer. Actually, they're not that expensive to replace, but the components can be split apart and inspected by a crafty (motivated individual), and often fixed for little to no cost. When they do fail it's usually b/c they were (murdered) overworked by an otherwise prolonged leaky air system. Solenoid manifold assemblies, again, can be disassembled and checked. Circuit boards can be checked for bad solder joints. That only costs time.

But usually it's the simple things that trip up an air system: Leaky hose connections, level sensors/connectors, air solenoids, leaky strut bladders, cracked air hose. Those items are exposed to the elements, stones, corrosion. The thing is, it takes time to diagnose an air suspension system. Something dealer service techs hate to do (owners don't like paying a LOT for diagnostic time). Lot of dealers like to remove part A and replace it and get on to the next vehicle. It takes time and troubleshooting skill/effort to diagnose an air suspension system.

Reading the manual will probably seem somewhat dizzying at first, unless you like to read manuals (like I do!). I would recommend a quick read-through. Take a break, then go visually inspect your truck's system, using the knowledge you gleaned your first time through. Then, if you didn't find anything, come back and read the manual in greater detail once you have a greater sense of familiarity with how it all goes togther and what the parts & pieces are. The second reading will make a lot more sense. There are some Y/T videos on it too. Start with the highest probability of failure items I listed. With all the possibilities, many of them simple, NOBODY is going to be able to say with any accuracy whatsoever, "Do this" or "Do that" to solve your problem. A visual inspection might just find the problem. But if not, a scatter-gun troubleshooting approach will just lead you down frustrating wasted-time paths. Start with a comprehensive visual inspection of all the components, fuses, connectors, bladders, etc. Then perform what the manual indicates for troubleshooting. It's ALL in there. You might find the problem right away. Once you have the system under your belt, you'll be smarter next time ...and the king or Ram air suspension! :D

BTW, When working properly the air system is a fantastic option.
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