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Check engine light on my new trail boss

Olok

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Any ideas why?
I recently purchased a 2021 TB (7days ago), I only have 200+ miles, and my check engine light turned on. The diagnostic alert indicated: service the engine and transmission system, and service the lithium ion battery.

So, today I took my TB in for service and it was returned to me with without the check engine light. The dealer service reported indicated "complaint cannot be replicated"

2 blocks from my house the check engine light came back on..-of course. The diagnostic alert indicates the same issue.
 

Spyderwebb

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I've had my 2020 for about 6 months, during the first week my check engine light came on twice. The dealer could not identify a problem, said the light was related to the brake system and another thing (that I can't remember), they reset the ECM and cleared it and that was that.

After doing forum searching I came across this thread:
I did the torque check of the UBEC bolts that hold the main fuse panel down, no problems since, so maybe it was a good idea to check!

This other GM forum has a lot of activity for these T1 trucks (Chevy & GMC) subsequently it has a lot of interesting threads and good input from a lot of subscribers.
 
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tbuss5831

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When these trucks came out I was getting a ton of them coming in with DTCs in the brake system control module. After being out for a few years engineering finally found out it was just software issues in the module itself setting the code for no reason. Also lithium Ion battery ????
 
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Olok

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My TB has been in the dealer shop this week and I'm expecting it back on Monday if all goes well.

The service team was to reach out to GM engineers, it seems the problem maybe a bit more challenging than expected.

As for the check lithium ion battery, Onstar sent it to me through its advance diagnostics messaging service equipted in my TB. I also provided this to the dealer who in turn used this info to check certain points, terminals, and the battery itself, or at least thats what I was told.

Thanks tbuss
 

tbuss5831

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My TB has been in the dealer shop this week and I'm expecting it back on Monday if all goes well.

The service team was to reach out to GM engineers, it seems the problem maybe a bit more challenging than expected.

As for the check lithium ion battery, Onstar sent it to me through its advance diagnostics messaging service equipted in my TB. I also provided this to the dealer who in turn used this info to check certain points, terminals, and the battery itself, or at least thats what I was told.

Thanks tbuss
Yea OnStar is dumb. Be nice if you actually had a DTC I could help you more. Also you don't have a lithium ion battery, well other then the telematics backup battery, in the truck that's why I was confused.
 

jonathanv

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Any ideas why?
I recently purchased a 2021 TB (7days ago), I only have 200+ miles, and my check engine light turned on. The diagnostic alert indicated: service the engine and transmission system, and service the lithium ion battery.

So, today I took my TB in for service and it was returned to me with without the check engine light. The dealer service reported indicated "complaint cannot be replicated"

2 blocks from my house the check engine light came back on..-of course. The diagnostic alert indicates the same issue.
I also have a 2021 TB. I've had mine since November, with 6,000 miles on. The check engine light flashed 5 times then disappeared. I took it in to the shop last Wednesday and they fixed it. They told me it was indicating that the engine was misfiring. Then they told me there was a problem with the software and they had to update it. After a day of driving, the check engine light turned on again but this time stayed on. The Chevrolet app says there is a problem in the exhaust emission system. It's back in the shop again.
 

vezePilot

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I use a Diablo i3 Performance Programmer to read OBD II codes in my Corvette. There is a Custom Tune in this hand-held that brings out the Real Corvette in my 2007 Base A6 3LT LS2 coupe. I got the Custom Tune from Lew.

It is also capable of supporting a Tune for my trucks, but I did not use this for my 2011 Silverado, and have not yet for my 2021 TB.

This Performance box is great for Reading OBD II codes ... and for resetting them. Occasionally codes are spurious, meaningless and can simply be reset without worry. I have a coupla other OBD readers, but the Diablo i3 is by far the best and easiest to use.

And for a Custom Tune ... I have not had any complaints and nor do I have any financial arrangement with Lew. But there is a guy who will analyze data collected with a Diablo i3, and he does excellent work using this data in upgrading performance and economy with the i3 for your vehicle. DiabLew:

edit: Scroll down a bit for offers regarding 2017 model years and thereafter.
 
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Remanaz

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Diablews list only shows 2017 thru 2018 for the silverado. GM found a way to lock the ecm to where the tuners have to replace or open up and modify your factory ecm in order to be able to tune them. It is possible that the i3 you have won't work with the 19 and up trucks even with the ecm modifications.
 

DonJinIA

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I've had mine come on twice since I bought the truck last Feb.
My OBD II code reader said it was a random misfire.
I cleared the code each time.
I also changed gas stations and have not had the problem since.
 
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