2011 Denali Stabilitrack, Traction Control, ABS, and suspension leveling pump down for the count

[ForcedTQ]

Well, thought I was going to jump back in the rig and have a better ride and functioning rear leveling once I got done with the rear shock install tonight. Boy was I wrong, pump doesn't even kick on now like it did when I started it up to pull it in the garage this afternoon. Normally it will do it's kick on every time the rig starts, but didn't when I went to take it for a test ride. Dash lit up like I didn't want to see, ABS light, Traction Control, and the DIC is saying traction control and stabilitrack are off. I've done some searching, and I can't see how changing out the rear shocks, (I installed genuine AC Delco 580-1093,) should be causing any of this.

Any ideas of where to start and what to look for? Everything was working fine before I changed the shocks (other than the leveling bags leaking air, because the compressor WAS working.)

Used my FlashScan V2 to scan for DTCs, nothing set, nothing pending....

 

[Doubeleive]

Well, thought I was going to jump back in the rig and have a better ride and functioning rear leveling once I got done with the rear shock install tonight. Boy was I wrong, pump doesn't even kick on now like it did when I started it up to pull it in the garage this afternoon. Normally it will do it's kick on every time the rig starts, but didn't when I went to take it for a test ride. Dash lit up like I didn't want to see, ABS light, Traction Control, and the DIC is saying traction control and stabilitrack are off. I've done some searching, and I can't see how changing out the rear shocks, (I installed genuine AC Delco 580-1093,) should be causing any of this.

Any ideas of where to start and what to look for? Everything was working fine before I changed the shocks (other than the leveling bags leaking air, because the compressor WAS working.)

Used my FlashScan V2 to scan for DTCs, nothing set, nothing pending....

ya when changing the rear shocks there is a bulletin about the rear abs connector coming undone because it sits right where the top bolt for the shocks go in, while installing shocks sometimes the harness comes undone, check that.
also be sure the electronic connectors for the shocks are on properly and that the ride height rods are on properly
other than that if the shocks are aired up and firm (squeeze them) then the it's possible the pump relief valve is not working properly, the pump may or may not inflate each and every time the key is turned

 

[Joseph Garcia]

As @Doubeleive stated, check the ABS wire connectors on both sides. The connectors sit on the top of the frame, right above the axle.

When I changed out my rear suspension, I accidentally disconnected the ABS connector on the left side, and ended up with warnings just like yours. I was able to trace down the source, using my Tech 2.

Let us know.

 

[Geotrash]

Well, thought I was going to jump back in the rig and have a better ride and functioning rear leveling once I got done with the rear shock install tonight. Boy was I wrong, pump doesn't even kick on now like it did when I started it up to pull it in the garage this afternoon. Normally it will do it's kick on every time the rig starts, but didn't when I went to take it for a test ride. Dash lit up like I didn't want to see, ABS light, Traction Control, and the DIC is saying traction control and stabilitrack are off. I've done some searching, and I can't see how changing out the rear shocks, (I installed genuine AC Delco 580-1093,) should be causing any of this.

Any ideas of where to start and what to look for? Everything was working fine before I changed the shocks (other than the leveling bags leaking air, because the compressor WAS working.)

Used my FlashScan V2 to scan for DTCs, nothing set, nothing pending....

Note that if you installed the Dorman pump, it will not perform a self-test at startup like the OEM pump does, but it WILL engage just fine when you put a load in the cargo area or hook up a trailer that weighs down the backend. Personally, I think that's a good thing that will extend the life of the pump.

 

[donjetman]

Our compressor and shock bladders are shot. The only thing we get is a message at most every startup saying check rear suspension.

 

[ForcedTQ]

Just found the issue.

As many have said, I found the right rear ABS sensor slightly apart, found it by feel, as being on top of the frame rail and behind the upper shock mount it's hard to get your head up there. I need to get a new inspection mirror. Thanks to all for the advice, I really appreciate it, you are all AWESOME!

Yes, I did check the shock electrical connections and the ohm readings on the shocks themselves, everything checked out fine. Still running on the OEM pump @ 252,000 miles. Now I'm going to put a load in the back and see if I can get the pump to kick on and air up the bladders.

 

[ForcedTQ]

Took about 350lbs and a minute of engine on time to get the pump to kick on, but the collapsed bladders popped out of the shocks and the system is holding air!

Is there an easy way to check to make sure the exhaust valve is operational? I removed the load and the back end didn't drop any when the engine was turned back on.