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Anyone have a check engine light show up then go away and come back? Code uo129 lost communication with brake control module, UO101 lost communication with transmission Control Module. Went to bed with no check engine light, woke up in the morning for work and noticed the truck would not remote start. When I go in to head to work noticed check engine light. After work ran codes. Shortly after getting codes and using google to research check engine light was gone. Went for a drive never came back on. Woke up this morning it was on again. Can anybody relate?

Edited by 5JB
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  • 3 weeks later...

You should look at these 2 links:

https://www.gm-trucks.com/forums/forum/245-2019-silverado-sierra-troubleshooting/?sortby=last_real_post&sortdirection=desc&page=2

 

 

You need to make sure that nothing is drawing voltage from the battery when the engine is off or causing any interference with the computer. 

My dealer told me that GM has already notified the dealers to tell the customers about issues with using aftermarket sigaret plugins. 

 

Edited by AMPRG
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  • 3 months later...
  • 1 month later...

I had the same code for my 2019.

i was using the 12v outlet, charging devices from a separate inverter , without the vehicle running ( trying to save fuel) I guess I drained the vehicle battery down too much. That’s when the engine light came on with that code. I now use the factory built in inverter that came with the truck. 1 outlet in the dashboard,the other in the bed. This set up works only with the motor running. So while I’m driving I charge everything then.

hopes this make sense and help out in the future.. 

p.s. I cleared the code myself, never came back on since. It’s been 8 months and 15k miles.

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  • 1 month later...

I have a 2019 Silverado with the 2.4L turbo 4 ecotech engine.  I started it today for the first time since Monday after several days of a cold snap.  Since it has been sitting for a few days I remote started it.  When I went outside about 5 minutes later the cooling fan was screaming.  I started the truck and drove about a mile to the store.  When I restarted the truck after leaving the store the cooling day wasn't screaming anymore but the check engine light came on and stayed on.  Now the remote start won't work.  Bringing it in Monday.  This is the first Chevy I've had in almost 20 years and it only has 491 miles on it. . I'm beginning to think I should of stayed with Ford.

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  • 1 month later...
On 5/18/2019 at 3:55 AM, AMPRG said:

You should look at these 2 links:

https://www.gm-trucks.com/forums/forum/245-2019-silverado-sierra-troubleshooting/?sortby=last_real_post&sortdirection=desc&page=2

 

 

You need to make sure that nothing is drawing voltage from the battery when the engine is off or causing any interference with the computer. 

My dealer told me that GM has already notified the dealers to tell the customers about issues with using aftermarket sigaret plugins. 

 

Interesting because my truck has been running fine until I hooked up a dash cam in the 12v plug. Left it plugged in and came back to start the car and got all kind of error codes. Unplug the dash cam clear the codes and everything seems to be fine now. 2020 Sierra. 

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  • 4 weeks later...

Anyone else having this issue? I had the same CEL issue where it was on for a few days and now off. Dealer said it was the same communication codes mentioned in the previous posts. However, they said that the most recent software that came out 1/16/20 was supposed to address this exact issue. So now they are setting up a loner and need to do deeper investigation with the truck in partnerships with GM engineers. I’m really loosing faith in the vehicle at this point as this is my 7th warranty repair issue. Anyone else still having this issue?

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  • 1 month later...
On 1/9/2020 at 10:56 PM, TruckerD said:

Interesting because my truck has been running fine until I hooked up a dash cam in the 12v plug. Left it plugged in and came back to start the car and got all kind of error codes. Unplug the dash cam clear the codes and everything seems to be fine now. 2020 Sierra. 

just curious,  how did you clear the codes?  do you have your own code reader/scanner that will do it?  the one I checked into would read codes, but not clear them,  the person at the auto parts store said the only one who can clear a code is the dealer

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2 hours ago, wizard4878 said:

just curious,  how did you clear the codes?  do you have your own code reader/scanner that will do it?  the one I checked into would read codes, but not clear them,  the person at the auto parts store said the only one who can clear a code is the dealer

That isn't remotely correct.  While there might be a really cheap code reader that can't clear codes, I haven't come across it yet.  It MOST DEFINITELY is not a dealer-only function.

 

I've got 3 code readers, one that cost about $100, another that cost about $400, and another that runs on my laptop that cost about $600.  While the more expensive code readers can read codes from more systems on my truck, they all can clear codes.

 

As well, codes will clear automatically as you fix the problem causing them.  Some will clear right away (for example, if you left the MAF sensor unplugged and you plug it in), others will require a certain number of key cycles or a specific driving/engine usage pattern to clear.

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On 4/26/2019 at 7:12 PM, 5JB said:

Anyone have a check engine light show up then go away and come back? Code uo129 lost communication with brake control module, UO101 lost communication with transmission Control Module. Went to bed with no check engine light, woke up in the morning for work and noticed the truck would not remote start. When I go in to head to work noticed check engine light. After work ran codes. Shortly after getting codes and using google to research check engine light was gone. Went for a drive never came back on. Woke up this morning it was on again. Can anybody relate?

This started to happen to my 2019 Elevation today. Same stuff, remote start wont work and CEL on. Did you ever find out what was happening or the fix for it? I got an appointment Tuesday. I had a 2015 Seirra SLE and traded in for the 2019. The 2019 has been to the doc(dealer) more then my kids for recalls.

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There have been at least two different GM documents regarding this concern, both required engine control module software updates as remedies.  Additionally as mentioned aftermarket 12v accessories left plugged in with vehicle off are known to cause concerns. 

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  • 4 weeks later...
On 2/3/2020 at 12:07 PM, bobboberton1 said:

Anyone else having this issue? I had the same CEL issue where it was on for a few days and now off. Dealer said it was the same communication codes mentioned in the previous posts. However, they said that the most recent software that came out 1/16/20 was supposed to address this exact issue. So now they are setting up a loner and need to do deeper investigation with the truck in partnerships with GM engineers. I’m really loosing faith in the vehicle at this point as this is my 7th warranty repair issue. Anyone else still having this issue?

Im in the exact same boat. I feel like my truck has been at the Service center longer than I had the truck. Did you ever get yours back?

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