Air Suspension in 2017 Tahoe pumped up

[grodskib]

Hello. I own a 2017 Tahoe. My issue is that the rear air ride suspension is stiff and the ride is extremely bumpy. I took it to a mechanic who I trust and he found only a communication code that came up. He was able to control the air suspension with the diagnostic device, meaning he was able to lower and raise the backend. He lowered the backend through the device BUT when he started the engine it slowly filled up. They test drove the car and could feel the suspension get stiffer as they drove. Eventually it filled up. Clearly its not a a relay or a compressor. Any ideas?

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

It is either the air suspension control module, or it is the compressor. When the truck is level, the air suspension control module sends a command to the air compressor to stop. So, either that command is not being sent, or the compressor is either not receiving the command, or is receiving the command but failing to turn off.

What is the specific code number that the mechanic received, as he was troubleshooting the system?

 

[Doubeleive]

well the specific code could have been a clue but since that wasn't provided it's possible there could be a ride height sensor issue or the relief valve is not working properly, meaning it may work manually via the diagnostic control but not on it's own.
you can do a simple test it may require 2 people
1. 1st person stands or sits near the left rear wheel area and listens
2 the 2nd person starts the vehicle
3 1st person listens very carefully to the air pump, right after the vehicle is started you should hear the pump exhale (release some air) then in about 1 second or less the pump will run for a few seconds to re-inflate the shocks and shut off.
that would be normal operation
there are some occasions where the pump may not run EVERY time, but in general it should
the fact that the shocks are very firm suggests to me the relief valve is not working properly and the pump may need to be replaced, but you may want to check what that code was also if a ride height sensor is not working properly it could possibly cause the same issue because the pump could be being told the height is not enough so it just keeps pumping and it's also possible if this were the case you would have a service suspension message on the screen when you start the vehicle so I would still lean towards the relief valve if the code is not related to the suspension and if there is no service message on the screen.

 

[ivin74]

I donot think is the compressor or the shocks. It could be the steering position sensor, or the yawl rate sensor. When one of those two sensors go out the shocks get stiff. Those sensors send out a code. Get the codes and start there.

As a temporary fix you can disconnect the wires that go to the shocks. By doing this the shocks will ride like any other shock. Do not disconnect the air lines.

 

[ivin74]

Double post

 

[grodskib]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

It is either the air suspension control module, or it is the compressor. When the truck is level, the air suspension control module sends a command to the air compressor to stop. So, either that command is not being sent, or the compressor is either not receiving the command, or is receiving the command but failing to turn off.

What is the specific code number that the mechanic received, as he was troubleshooting the system?

Thanks for your reply. I do not have the codes nor does my mechanic remember them. I took it to the dealer and they only wanted to replace the shocks and said they were siezed. So I have to find a mechanic who will trouble shoot.

 

[grodskib]

I donot think is the compressor or the shocks. It could be the steering position sensor, or the yawl rate sensor. When one of those two sensors go out the shocks get stiff. Those sensors send out a code. Get the codes and start there.

As a temporary fix you can disconnect the wires that go to the shocks. By doing this the shocks will ride like any other shock. Do not disconnect the air lines.

Thank you. I wll give that a try as I cannot find anyone who will figure this out. My dealer jusyt wanted to replace my shocks.

 

[grodskib]

well the specific code could have been a clue but since that wasn't provided it's possible there could be a ride height sensor issue or the relief valve is not working properly, meaning it may work manually via the diagnostic control but not on it's own.
you can do a simple test it may require 2 people
1. 1st person stands or sits near the left rear wheel area and listens
2 the 2nd person starts the vehicle
3 1st person listens very carefully to the air pump, right after the vehicle is started you should hear the pump exhale (release some air) then in about 1 second or less the pump will run for a few seconds to re-inflate the shocks and shut off.
that would be normal operation
there are some occasions where the pump may not run EVERY time, but in general it should
the fact that the shocks are very firm suggests to me the relief valve is not working properly and the pump may need to be replaced, but you may want to check what that code was also if a ride height sensor is not working properly it could possibly cause the same issue because the pump could be being told the height is not enough so it just keeps pumping and it's also possible if this were the case you would have a service suspension message on the screen when you start the vehicle so I would still lean towards the relief valve if the code is not related to the suspension and if there is no service message on the screen.

THank you! I will give that a test.