Jump to content

Stiff, Rough Suspension Problem Fixed

2019Tahoe

By 2019Tahoe
in Troubleshooting & Recalls

 Share

Recommended Posts

2019Tahoe New Member

2019Tahoe

Posted
Posted (edited)

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 by 2019Tahoe
Corrected grammar
newdude Senior Enthusiast

newdude

Posted
Posted
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.

 

 

  • Like 1
2019Tahoe New Member

2019Tahoe

Posted
  • Author
Posted

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 New Member

2019Tahoe

Posted
  • Author
Posted

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

txcj New Member

txcj

Posted
Posted (edited)

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 by txcj
Grammar
  • 3 weeks later...
txcj New Member

txcj

Posted
Posted

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 Senior Enthusiast

davester

Posted
Posted

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.

  • 3 years later...
  • 1 year later...
levonh Enthusiast

levonh

Posted
Posted (edited)

Yes where is the relay located?

I'm having the same rough ride with no codes or DIC display.

 

Edited by levonh
Added code info.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Aimatdeer
      Ac not keeping up

      By Aimatdeer · Posted

      I was using recirc/max air. Especially if it really hot i start out by lowering the front windows a little with regular ac the go to recirculation after a few and rolling windows up. And it does not have the newest refrigerant. It has per the info under the hood r134. Not the new r1234yf.  
    • Atlas
      AC diagnostic on a neo-classic Camaro

      By Atlas · Posted

      tldr; Shade tree mechanic stumped by variable displacement AC compressor.   Not Silverado related, but for my 2000 Camaro SS. I've never really used the AC since acquiring the car a good handful of years ago. I plan to take it on a trip this summer so I wanted to make sure the AC was in good shape. On an 73 degree day in the shop with the car idling I set the AC on "Max", temp set to cold, and fan on hi. The compressor turned on and air turned nice and cold.   I let it run for several minutes but noticed the compressor never cycled off. The engine was up to temperature enough that it began cycling the cooling fans on high. I had a set of manifold gauges hooked up and it was consistently at about 25 psi on the low side and between 200 and 225 psi (warm engine) on the high side. Per temperature charts, the low side is low (should be 30-35) and the high side is a little high (up to 170 per chart). I read the low pressure as potentially being under-charged underscored by a continually running compressor This was also underscored by temp readings of mid-20 degrees at the vents. Not just cold, freezing cold. Switching off the AC but leaving the HVAC fan on high produced a deluge of condensation underneath the vehicle. I was getting ice buildup on the evap core most likely.   The low reading (25psi) concerned me that the compressor wasn't switching off so I swapped out the pressure switch. No change in behavior, still ran constantly.   The AC clutch works fine as it engages/disengages with the HVAC switch on command. The compressor relay is good as I swapped it with two different known good relays just to be sure. Having eliminated that, and the pressure switch, I added refrigerant, thinking the constant run and low "low" pressure were signs of a slight undercharge. Makes sense, the car is 26 years old and it doesn't appear the AC system has ever been touched.   Adding some R134a didn't meaningfully change the low side pressure. And that's when a lightbulb flashed upstairs. While I consider the car "old", it's possibly "new" enough to have a variable displacement compressor. Did some reading and sure enough. Dangit. I don't work on these for this reason.   Adding refrigerant means the compressor will just compensate and won't really change pressures until it's severely overcharged or undercharged. But at least I wasn't getting ice/frost anymore, but instead high 30 degree temps out of the vents. That's more normal, but with variable displacement now I have no idea where my charge level is at. It's probably overcharged now. The high side even with the engine radiating serious heat was never really over about 225.   The static pressure at room temperature is dead on, before and after the charge. Both high/low equalize after some rest.   I'm thinking I'll need to take it to a shop. I want the proper charge level so I'm not working the compressor too hard. The only way to get an accurate charge is to evacuate and then re-charge with the exact amount specified for the system -- at least that's what I'm reading.   Anyone here with modern automotive AC knowledge?  
    • Byrds8
      Ac not keeping up

      By Byrds8 · Posted

      Mine is in the shop for the AC now. While it did get cold after a bit, it would take a while to even start to cool the air at all. Turns out the compressor was bad and cycling. 
    • KARNUT
      Ac not keeping up

      By KARNUT · Posted

      I call B.S. when I first moved to Texas my first house would only cool to 80 with the Texas heat. The AC tech said it was normal at 100 degrees outside. I remodeled the house put in a new AC. I could hang meat. My cars may need recirculating to start. Once moving it switches to regular AC and I could hang meat. Living in Texas no one would put up with only 20 degrees difference. 
    • Silverado4x4
      Ac not keeping up

      By Silverado4x4 · Posted

      AC in home or auto only cool down 15-25 degrees from outside temp, but what will help is to put the ac in recirc mode this will recirc the Inside cabin air rather then trying to cool down the outside hot air, I always have mine in recirc mode.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...