2012 Duramax 6.6L LML — P20B9

Andrew from De Motte Technician Posted   Latest   Edited  
Case Study
Driveability
2012 Chevrolet Silverado 2500 HD LT 6.6L (8 LML) 6-spd (1000)
P20B9 - Reductant Heater "A" Control Circuit/Open

Here is another Duramax case study. More than anything I want to share with you all on how to reset the warning message once the repair is completed. I will be adding to this one later on a 2015 with the same issue. I want to walk you all through it with GDS2 as well. 

docs​.​google​.​com/presentation/d…

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Bill from Rosetown

 

Technician
 

Nice Andrew!

Does the DEF tank need to be completely filled before running the resets and testing the heaters?

Is there a reductant data reset that should be performed after the level reset? I seem to remember after the all 3 sensors read active and the level reset is performed to bring PID to 100% that the reductant data reset should be performed afterwards. I think there are differences from year to year and model to model?

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Andrew from De Motte

 

Technician
 

I always re-fill the tank. You do not have to do it but for me these trucks have a special policy until 120k for the heater. So I refill every one of them. You are correct year to year is different. I got to be honest I see these a ton, and I still have to look it up all the time. I'll never forget the first one I did and could not get the message to reset. I will also confirm a Snap-On scanner will do all of these functions. Re-gen with their product is where it gets tricky/spotty coverage. The next fluid quality message I get I will make another slide. Those if you have not done them are even more "fun". And those faults are where some of the aftermarket tools have their short comings.... even tech2win will let you down if an older truck. Those I will still grab the ol trusty tech 2.

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Mario from Weston

 

Diagnostician
 

Loving the slide format, great post Andrew 👍

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Andrew from De Motte

 

Technician
 

Thanks Mario... for me I find it the best way to let people follow my diagnostic flow, and reasoning.

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Michael from Jurupa Valley

 

Owner/Technician
 

Nicely put together slides of repairs (visuals are awesome); you used the Tech2 for the repair I see - did you purchase the tech2 aftermarket or off the truck?

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Andrew from De Motte

 

Technician
 

I used Tech2Win for this one (PC based) I am a GM dealer tech so we have Tech2's but I use Tech2 Win most of the time through my MDI2.

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Glen from Arthur

   

Owner/Technician
   

I use these for those type of DEF fittings & lots of other fuel line connectors

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