Air Shocks not Pumping Up?

[bad_idea]

I have a 2018 Yukon XL Denali with the MagRide / air shocks in back. I swapped in a set of ARNOTT AS3429 to delete the MagRide but retain the air shocks to level the truck out when towing. Swapped the shocks in July of last year. I have towed since installing them and the truck leveled out nicely. I towed this past weekend and it did not level out. I stuck my head under the back of the truck and did not hear the air compressor pumping up.

This is my wife's daily, so no telling how long the pump hasn't been pumping. The ride quality unloaded is good. What has me perturbed is there are no error codes on the dash, I would think it would throw a code. I do all my own repairs on my older vehicles, but come up short with these newer vehicles. Can you all point me in the right direction on what to look into? Thanks.

 

[slupie]

I have a 2018 Yukon XL Denali with the MagRide / air shocks in back. I swapped in a set of ARNOTT AS3429 to delete the MagRide but retain the air shocks to level the truck out when towing. Swapped the shocks in July of last year. I have towed since installing them and the truck leveled out nicely. I towed this past weekend and it did not level out. I stuck my head under the back of the truck and did not hear the air compressor pumping up.

This is my wife's daily, so no telling how long the pump hasn't been pumping. The ride quality unloaded is good. What has me perturbed is there are no error codes on the dash, I would think it would throw a code. I do all my own repairs on my older vehicles, but come up short with these newer vehicles. Can you all point me in the right direction on what to look into? Thanks.

If you do not hear the air compressor running at strat up then it is dead. Common issue. I replaced mine in about half hour without lifting the truck up and mine is lowered 2/3.

 

[bad_idea]

I would have thought the computer would throw a code tho, common not to throw a code?

 

[Thrust]

Quick way to verify if the shocks have air in them is to squeeze the shock bladder. Does it feel like it has some pressure in it? You can also unplug an air line to a shock, plug it back in then turn on the SUV and listen for the pump to air the system back up.
The air pump doesn't run every time you start the SUV.

 

[Joseph Garcia]

Do you have a quality bi-directional scanner? If yes, it can assist you in troubleshooting the air ride system.

 

[Thrust]

Also an observation on this. Arnott has figured out how to seal the shock from leaking down after sitting. My air pump hardly ever came on with the Arnott shocks. Now back with GM Magnarides, air pump comes on every morning.

 

[bad_idea]

Did some work on the truck today and looked into the air ride system while I had it on stands. I pulled an airline from a shock, then started the truck - pump did not cycle.

I am fairly ignorant to these new vehicles and scan tools and such. What is a bidirectional scan tool?

Also, I was reading the troubleshooting procedures and say there is a K99 relay for the air pump. I can't seem to locate that relay. Can someone point me in the direction of it?

 

[bad_idea]

I think I found the relay, I am assuming it is the one taped to the harness by the fuse panel on the drivers side wheel well. I pulled the relay and checked voltage at pin 30, I got 6v to battery - terminal. That seems low - it may be my meter, or could it indicate a fault?

I started the truck and jumped across 30 and 87, compressor did not come on.

Thoughts?