Jump to content

2021 RST Speedo Off

Jetblackz28
 Share

Recommended Posts

Jetblackz28 Enthusiast

Jetblackz28

Posted
Posted

So I just got a 2021 Crew Cab RST, and I noticed that my GPS speed via my waze app was 1mph slower then what my trucks digital display reads. I know its not my phone/waze as they matched in my 2020 Silverado LT and in my wifes 2021 Traverse LT. And there is one of those speed radar trailers that sit on the side of the road and flash red when your going by to fast, and I set my cruise as I passed it and it showed a mile under what the dash read. Is there a fix for this?

Adamace1 Enthusiast

Adamace1

Posted
Posted

Most times I use GPS the truck or car will be 1 mph higher than the GPS. As the tires wear it will get closer to the same. I think gm wants to make sure the speedo is under not over. So people can't blame them for speeding tickets.

Adamace1 Enthusiast

Adamace1

Posted
Posted (edited)
13 minutes ago, Jetblackz28 said:

Thanks for being so helpful! 

I really think it's completely normal. If your truck was showing 50 but it was really going fast than that I can see people blaming/suing gm for their speeding tickets.

Edited by Adamace1
Jetblackz28 Enthusiast

Jetblackz28

Posted
  • Author
Posted
1 minute ago, Adamace1 said:

I really think it's completely normal. If your truck was showing 50 but it was really going fast than that I can see people blaming/suing gm for their speeding tickets.

That’s fine I can understand that as well. Just was seeing if this is a common issue or a way to get it fixed. 

It's Tim Senior Enthusiast

It's Tim

Posted
Posted
2 hours ago, Jetblackz28 said:

That’s fine I can understand that as well. Just was seeing if this is a common issue or a way to get it fixed. 

Please put down the phone and drive, thank you.

Jetblackz28 Enthusiast

Jetblackz28

Posted
  • Author
Posted
1 minute ago, It's Tim said:

Please put down the phone and drive, thank you.

Another brilliant post! Thanks so much for you thoughtful insight on the topic!

newdude Senior Enthusiast

newdude

Posted
Posted (edited)

Operating as designed.  There is a 1-2mph +/- variation allowed.  Nothing you can do about it. 

Edited by newdude
Salsa De Piña Enthusiast

Salsa De Piña

Posted
Posted (edited)
13 hours ago, Adamace1 said:

As the tires wear it will get closer to the same.

As the tires wear, the discrepancy will get larger (on the order of another 1 or 2 MPH at 60 MPH.)  I assume Jetblack will have an aneurysm by then.

Edited by Salsa De Piña
Jetblackz28 Enthusiast

Jetblackz28

Posted
  • Author
Posted
1 hour ago, Salsa De Piña said:

As the tires wear, the discrepancy will get larger (on the order of another 1 or 2 MPH at 60 MPH.)  I assume Jetblack will have an aneurysm by then.

It’s funny, I came in here asking a simple question as I’ve never seen the speedo off on any stock vehicle especially a brand new one with under 500 miles on it. And most people’s answers weren’t helpful at all or even productive to the conversation. I have no problem dealing with my speedometer being off by 1mph if that is occasionally normal but I’ve never seen it so I asked a question.

KARNUT Senior Enthusiast

KARNUT

Posted
Posted
It’s funny, I came in here asking a simple question as I’ve never seen the speedo off on any stock vehicle especially a brand new one with under 500 miles on it. And most people’s answers weren’t helpful at all or even productive to the conversation. I have no problem dealing with my speedometer being off by 1mph if that is occasionally normal but I’ve never seen it so I asked a question.

I use that app for navigation even with vehicles equipped with navigation. In the three vehicles I’ve used it on the app read faster than the vehicle. Some by 2 mph. My CRV read the closet.


Sent from my iPhone using Tapatalk
ThatredneckguyJamie Enthusiast

ThatredneckguyJamie

Posted
Posted

the problem you're running into is most people don't care or see an issue with such a small variance, BUT what they do love is a chance to add a smart comment or make a joke, instead of kicking back a response to each one of these...maybe lighten up and roll with it. 

For example..if someone says put down the phone and drive...maybe say instead...I would, but then how would I know what time it is since my clock is also off by 17 seconds

Jetblackz28 Enthusiast

Jetblackz28

Posted
  • Author
Posted
32 minutes ago, ThatredneckguyJamie said:

the problem you're running into is most people don't care or see an issue with such a small variance, BUT what they do love is a chance to add a smart comment or make a joke, instead of kicking back a response to each one of these...maybe lighten up and roll with it. 

For example..if someone says put down the phone and drive...maybe say instead...I would, but then how would I know what time it is since my clock is also off by 17 seconds

I gotcha, I’m not seriously bothered by anyone here. Just used to forums where people are are actually helpful.

Z45 Senior Enthusiast

Z45

Posted
Posted

Handheld GPS apps is only accurate to +/- 20 meters and sometimes can be way off if obstructions block some sats'.

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

      Monday looks like a good day for the dealer to test an ac issue. Hopefully it all turns out good.
    • CamGTP
      Gas Prices

      By CamGTP · Posted

      Paid $2.72 for E85 today.
    • Atlas
      Gas Prices

      By Atlas · Posted

      Welcome back! No, it definitely doesn't pass the sniff test. Even "ceasefire" needs an alternative definition these days.    $5.29 at Kroger today
    • bluev8
      Intermittent no-code issues on 2022.5+ V8 trucks — what did the shop fail to capture?

      By bluev8 · Posted

      That makes sense, and I think you are describing the real product problem. Capturing data is the easy part. If the owner or technician has to manually dig through five minutes of millisecond-level logs, the product has already failed. The device would be at the ECM harness, not at the OBD port, so I agree that data retrieval and event marking need to be thought through carefully. The way I am thinking about the architecture is: The recorder itself should not depend on a phone, app, Bluetooth, Wi-Fi, or cloud connection to capture the event. It should always keep a local rolling buffer and lock the event locally. A button, phone app, or small cabin device would only act as an event marker. If the driver feels a stumble and presses the button 10–30 seconds later, the pre-buffer has to already contain the useful data. For data retrieval, the practical options would be a sealed service USB lead, Wi-Fi download, or a phone/cabin companion device. I would not expect the owner to remove the ECM-side module or work with raw files directly. The cloud or AI side would be for interpretation, not for capturing the event. The truck may have no connection when the issue happens, so the evidence has to be saved locally first. After that, cloud processing could help decode the data, compare it against baselines, and generate a readable report. For the first version, I would keep the automatic triggers conservative and objective: driver event marker bus-off error passive voltage drop / brownout device reset FIFO or queue overflow a normally periodic message disappearing side-to-side communication mismatch, if the topology supports that For “learning normal,” I agree with your point, but I would not want to overclaim it as automatic root-cause diagnosis at first. A realistic first step would be learned baseline comparison for that specific vehicle and operating condition. For example, a value would only be compared against similar conditions: RPM range load / MAP throttle position gear / vehicle speed coolant and oil temperature battery voltage AFM/DFM state, if decoded and validated Then the report could flag things like: this periodic message disappeared compared with its normal timing this value deviated from this vehicle’s normal range under similar conditions the same abnormal pattern repeated after the same type of event the anomaly occurred together with voltage, oil-pressure, misfire, or communication changes But I would still call that “abnormal pattern detected,” not “replace this part,” unless there is enough validated repair data behind it. So the intended product would not be “here is a huge log.” It would need to be an event package: what triggered the capture how much pre/post data was preserved what changed before and after the event whether the device itself reset, overflowed, or saw a bus error selected graphs around the event raw data only as supporting evidence From your perspective, what would make this kind of report useful instead of just another datalog? For example: What are the top 5 parameters or events you would want highlighted first? Would you trust a learned baseline for that specific vehicle, or would you prefer fixed thresholds? How much false-positive flagging would be acceptable before you stopped looking at the reports? What would a one-page report need to show for an independent shop to take it seriously? For misfire, AFM/DFM, oil pressure, or U-code complaints, what would you want the tool to flag automatically?
    • scotthvac.net
      2022-24 halogen - led grille swap

      By scotthvac.net · Posted

      2024 Silverado 2500 HD LTZ grille no camera Parts list   84603331 84913656 84913657 84913654 84913655 84911567 84911568 85646092 85646093 85797921 85797922   11570637  x10-15   grille/bumper bolts 11546500  x10      grille clips 11571006  x10      push/retainer clips 11546454  x6       nut retainers 11611609  x6       M5 bolts 11610700  x6       molding/trim retainers

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...