Voltage & OEM air suspension problem.

[ram17]

2017 6.7 CC Aisin OEM Air suspension cold weather pkge- about 20k miles on the truck. The temps in for the last 4 days ranged between 15-25 F. Yesterday I turned the key to start the RAM without preheating. The crank was strong and the vehicle started quickly. The msg "service air suspension system" immediately appeared. Instantaneously, the voltage widow revealed 8v in red and then the voltage started bouncing around between 11v to 14 v. I turned the vehicle off. The next day the vehicle started right up without issue. I checked, there were no codes thrown and drove the RAM for 40 mins about 25 miles without incident. I suspect that all the msgs were fictitious but just looking for any thoughts. I am confused as to the relationship between the air suspension system and the battery/voltage.

 

[lpennock]

The Voltage cycles were the grid heater cycling. Normal in cold temperatures. You may have a battery going bad which is what caused the Air Suspension warning. Had you waited for the truck to warm up and then restarted you would probably have been fine.

 

[EDankievitch]

I’m betting your batts are starting to fail. My truck would give all kinds of strange messages every time the temps were below 20 for better than two years before they finally failed last year.

 

[ram17]

Thanks guys and that's what I believe. The only thing that causes me some doubt is that the cranking of the starter was strong and the Ram started right up. Usually a battery on the way out will have that slight hesitation before the starter turns over.

 

[Cummins12V98]

True but you just put an additional load with grid heaters pulling batteries also. Newer electronics don’t like low voltage.

 

[APay18]

Whenever temps are below 20° and my truck is off for a good 10 hrs then I get the “service air system” too but once running it turns off almost immediately. 2018 3500 CC Aisin 133k miles

 

[ram17]

Thanks to all who replied. One of the best if not the best most knowledgeable automotive Forms on the internet. A wealth of knowledge.

 

[EDankievitch]

Mine would start up nice and easy but the dash would show all kinds of strange messages afterwards. Service antilock brake, service air filter , etc then they would all clear out. Low voltage does some strange things to the systems on these trucks and the voltage does not have to be all that low to get messages

 

[Ozymandias]

Thanks guys and that's what I believe. The only thing that causes me some doubt is that the cranking of the starter was strong and the Ram started right up. Usually a battery on the way out will have that slight hesitation before the starter turns over.

Not with a gear starter.
I had this behavior only with direct drive starters.