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PSA: 85 MPH speed limiter trigger

mikemcclain

By mikemcclain
in Troubleshooting & Recalls

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mikemcclain New Member

mikemcclain

Posted
Posted

This is more of a PSA in case it happens to someone else.

 

I had new struts installed in the front 2 years ago, no problems.  Last year, I switched out the rear air shocks with no issues.  Very intermittently, I'll get a "service suspension" alert on the driver display.  I don't notice a change in handling or ride so never paid much attention.

Last week, I was traveling back from Keystone, CO, and the "service suspension" message came on.  I cleared the message and continued on.  Once out of the mountains, I attempted to set the cruise control but it wouldn't work.  All other steering wheel controls worked including cruise on/off, it just wouldn't set a speed.  Next, I was attempting a pass and around 85 MPH, the truck stopped accelerating regardless of pedal position.  I thought my transmission was going out (204k miles) but kept driving because the family was asleep and no CEL.  Truck would accelerate fine from 50-80 but at 85 it would just stop.  Well, doing some googling led to a discussion about the "service suspension" error triggering a mild limp mode where speed is limited to 85.  Stopped for gas, restarted the engine, and no problems after that and no service suspension message again.

 

Hope this helps someone.

  • 2 months later...
AngelS New Member

AngelS

Posted
Posted

Did you ever find out what the issue was? Was the struts after market? I'm experiencing the same exact issue with my 2019 Suburban

  • 3 months later...
mikemcclain8 Enthusiast

mikemcclain8

Posted
Posted

I put new shocks on the rear again a few weeks ago (65k miles on them and getting rough) and noticed one of the electrical connections wasn't "clicked" in.  I had trouble getting the new one to click in also until I spray the rubber with lubricant and it slid right it.  Haven't had the issue since then.  Also, the message/limiter would reset with turning the car off/on again.

 

BTW, the struts were put in by a shop so I'm not sure if it was OEM or after-market.

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