If anyone can help me out here it would be greatly appreciated. Ive been trying to get this resolved for the last year and I just cant figure it out. Im no sort of professional mechanic at all so I’m sorry if this is filled with dumb questions. Anyways here is the rundown:
My vehicle is a 2007 Chevrolet Tahoe LTZ
The service suspension system message popped up on my dash about 3 years ago. The shop told me all 4 shocks were popped and the compressor was dead and they wanted close to 4 grand to replace everything. That was out of my reach at the time so I left and just kept driving my truck and ignoring the message on my dash. I decided I was going to buy the parts and do it myself to save some money, and also because I was off work due to covid and needed something to do to entertain myself. So I replaced all 4 shocks, the rear shocks I installed two “Monroe Specialty Shock Absorber” which is part 40050 and then for the front I installed two “monroe speciality strut” part 40047 and then I replaced the compressor with an Arnott Compressor the part number is P3242. After replacing all parts I go to test it out and unfortunately im still in the same exact spot. My compressor does not turn on at all not for the self test when you start the car or anything. I have hooked up an autel maxisys elite which was unable to communicate with the electronic suspension control module so I coukdnt get any codes from it or do any tests. The same results occurred with my Bosch ADS 625, there is absolutely no communication with the suspension control module from either tool. Has this happened with any of you guys? Do you think its just a wiring issue or a short? Or do you think I need to replace the suspension control module? I live in Michigan and we get a lot of snow during winter which leads to lots of salt on the roads. The underside of my tahoe is pretty rusty from those conditions so maybe a bad ground? Any input you can provide is appreciated. Thanks

 

I would try cleaning module connectors with a good electronic cleaner/lube first to see if it will start connecting to the system again. Salt creeps into everything.
Suspension module is connected to the BCM so I'd clean it's connectors also as that's it's main data link.
Black wire is usually the main ground.
Of course check your fuses and relays also. Manual with diagrams is a must. I use alldatadiy for my fleet, subscription is not much and really needed for diagrams to check everything before laying out cash for modules.

 

One day this vehicle started acting crazy while driving. Very little power, guages going up and down, dash dinging and the door locks going up and down. All of this and the vehicle was barely running. I immediately thought bad ground. But after metering all the grounds and positive cables and I found no real issues with resistance in these cables. I did clean all terminals and used die electric grease to reconnect them tight. Nothing helped or changed the issue. Switching batteries etc. Started looking at the can bus network and found a real problem. The network can hi and low static voltage was not around 2.5v with nothing running. It was above 8v for hi and low. I started eliminating where the high can voltage was coming from. The first thing I unplugged was the abs module and the dash and vehicle came back to normal. I replaced this module with a used one and the same issue came back. Then I went to alldata and got the schematics for everything. I went down the vehicle closer to the rear and looked at the air ride suspension module. Unplugged it and bam back to normal running again. So I decided to jump the can terminals in to out on the suspension module plug to continue the network to the end resistor. This worked and then I decided to get a used module for it and once I removed my jumpers and connected the used module the vehicle ran for about 2 weeks without issues and then started doing the exact same thing again. I had my wife watch the dash when I messed with the suspension module and cables and it actually started to correct itself all the dash issues again. I jumped the network again and it runs fine. I now have the dash telling me the suspension system needs service, the stabilitrak and traction control both warn me also.
I wanted to eliminate the entire suspension air ride system to get rid of the dash warnings but with the module removed I don't think this will be possible. I'm starting to think the old air ride pump is shorting something out inside the suspension module and affecting the network which makes the vehicle stupid. Has anyone eliminated the air ride suspension system without the module and eliminated all the dash warnings that I am describing?
thanks in advance.