Stiff, Rough Suspension Problem Fixed

2019Tahoe · June 19, 2020

I bought a 2019 Tahoe with 37,000 miles from a car rental company. During a 1300 trip, the suspension went from just fine to rough as a log truck. Like all four shocks had been replaced with a solid bar.

Long story short, I took it to a dealer, which I seldom do. They diagnosed only the left rear shock was bad. They replaced it and all the others started working right. The reason I'm posting this is nothing I found on the internet mentioned this solution for the problem I had. Now if somebody else has this problem, hopefully they will find this post.

I was ready to remove all the magnaride shocks and struts, then install an after market kit doing away with it all. For now at least, I'm glad I didn't. If another one goes bad next month, I may feel differently.

I wish I knew how the dealer tech diagnosed the one shock bad. The vehicle was stiff on all four corners.

Edited June 19, 2020 by 2019Tahoe
Corrected grammar

newdude · June 19, 2020

11 hours ago, 2019Tahoe said:

I bought a 2019 Tahoe with 37,000 miles from a car rental company. During a 1300 trip, the suspension went from just fine to rough as a log truck. Like all four shocks had been replaced with a solid bar.

Long story short, I took it to a dealer, which I seldom do. They diagnosed only the left rear shock was bad. They replaced it and all the others started working right. The reason I'm posting this is nothing I found on the internet mentioned this solution for the problem I had. Now if somebody else has this problem, hopefully they will find this post.

I was ready to remove all the magnaride shocks and struts, then install an after market kit doing away with it all. For now at least, I'm glad I didn't. If another one goes bad next month, I may feel differently.

I wish I knew how the dealer tech diagnosed the one shock bad. The vehicle was stiff on all four corners.

The system can set 10 different DTCs so perhaps there was a code? 4 codes for the shocks (one code per wheel), 4 codes for the position sensors (one code per wheel) and two master codes.

If there is an issue, the truck can default to disable all 4 shocks.

Quote

Electronic Suspension Control Operation

The electronic suspension control (ESC) system uses the information from other systems in order to execute certain functions.

The ESC system does not have a malfunction indicator lamp, but instead uses the instrument panel cluster (IPC) for the display functions. When the ESC system detects a malfunction that sets a DTC, the ESC system sends a message on the serial data line directly or through the powertrain control module (PCM) to the IPC, which will display one of the following messages:

SERVICE SUSPENSION SYSTEM or SERVICE RIDE CONTROL

SPEED LIMITED

The SERVICE SUSPENSION SYSTEM or SERVICE RIDE CONTROL message will only be displayed if the ESC system detects any malfunction that sets a DTC. The ESC system will send a message on the serial data line to the IPC to display this message.

The SPEED LIMITED message will only be displayed if the ESC system detects a malfunction that sets a DTC and causes the ESC system to disable all 4 shock absorbers. The ESC system will send a message on the serial data line to the PCM indicating that 2 o more shock absorbers were disabled. The PCM then sends a message to the IPC to display this message.

The ESC module has the ability to store DTCs as current or history codes. Most ESC system malfunctions will display a message in the IPC and set a DTC. The message will remain ON until the RESET button is pressed on the driver information center (DIC). As long as the DTC is current, the message will be displayed after every ignition cycle and the RESET button must be pressed to bypass the message.

The ESC system uses an ignition cycling diagnostic approach in order to reduce the occurrence of false or intermittent DTCs that do not affect the functionality of the ESC system. This allows for the fail-soft actions to be taken whenever a malfunction condition is current, but requires the malfunction to be current for a certain number of ignition cycles before the corresponding malfunction code and message will be stored or displayed.

2019Tahoe · June 20, 2020

Thanks for sharing all that info, Senior Enthusiast. Before taking it to the dealer, I bought a $35 code reader on Amazon (recommended by Scotty Kilmer). It said there were no trouble codes present, but I'm guessing for $35 it wasn't looking deep enough. Definitely makes sense that all four shocks failed because of a malfunction somewhere in the system. I didn't recognize any error messages on the DIC, but the vehicle was brand new to me and I wasn't familiar with the instrumentation. I could have missed it

2019Tahoe · June 22, 2020

Is there a way to soften the ride by changing settings? The original problem was fixed. A softer ride would be nice.

txcj · June 22, 2020

I have a 2018 Tahoe Premier with 60k miles and have the same problem right now...terribly stiff suspension. I also notice the compressor does not come for a short bit after I start the vehicle(I think it's supposed to). Today I checked the 2 fuses I know of (# 5 suspension leveling compressor, and #45 ALC run/crank, any more I need to check?) and both were good. I checked the operation of the ALC relay and it was good. With the relay out, I jumpered the connector and the compressor turned on. I also started the vehicle and tried to see if there was a signal going to the relay to turn it on, but I was not able to confirm that signal is being sent to the relay. I'm guess I, too, have a DTC but who knows which one. I'd like to buy me an aftermarket Tech2 scanner but have no idea if they work properly or would allow me to run functional tests of this system like I see online. Can anyone recommend a scanner that could see DTCs down to this level?

@newdude: Thank you for that info.

Edited July 13, 2020 by txcj
Grammar

txcj · July 13, 2020

Just to follow up, the local automotive repair shop diagnosed my problem as failed front shocks...$1700 dollars to replace. I paid it, then found out they replaced the front shocks plus they didn't tell me they replaced the left rear, too (same position as Wild Bill's). I noticed that one was replaced on my own a day later. When I went back and asked them about it, they said they replaced it "on their dime because changing the front shocks helped, but didn't totally solve the problem." Trust = low. I was rushed for time as I was headed out on a 2000 mile vacation the next week, but now I think I would do it for myself. All except the front coil squeezes and the ride height trim procedure. Can anyone recommend a mid-level ODB2 scanner that can perform this reset on my 2018 Tahoe? I saw this vid from Xineering LLC that shows an Autel MaxiDAS DS808 can do it...is there anything cheaper?

davester · July 14, 2020

If you've got a Windows laptop, then something like Autogenuity w GM Enhancement would probably be able to do it. But, I would first confirm with Autogenuity that it can do it, before purchasing it... I bought it for my '04 Sierra, and it works great for me for diagnosing stuff.