How did you make out. Just got my truck back from dealer said wire harness to heater had a melt down and they replaced. Wondering if it's gonna happen again or if heater is drawing too many amps?

 

There's a software update for this issue..
Make sure you get it done.. The dealer should have done it before you picked it up..

 

Ok they did the update first but upon pickup still had the issue so I left for another day and they replaced the harness with melted plug. Hopefully won't happen again.

 

...a little bit worried. My truck is in for a Def Heater and waiting for parts (2 weeks so far). They did not mention any update or if the harness was ok...When the truck is having the codes cleared/reset, will that update show up automatically for them to perform it?...and will they obviously see the damaged harness if it is damaged?

Apologies in advance...I'm a retired mechanic and have a HARD time letting others work on my stuff still. sigh.

 

They did the software update first, I guess there was a bulletin for the update. Didn't solve the "service def system" message so they looked further and found the plug on heater harness melted. My understanding is this shouldn't happen again now that software was updated

 

Only problem is I was down last week and replacing harness is not a option. Dealer says whole tank and it’s on national back order. Good luck! I located my own part and paid for it out pocket. My dealer was fantastic! I did the work and dealer fit me in for programming. All updates were done before replacement. No eta on parts. I’m seeing minimum 3 weeks or more!

question- does anyone know once the update is completed is the def heater light supposed to light up when vehicle is started? It does shut right off. Is this as part of update?

 

question- does anyone know once the update is completed is the def heater light supposed to light up when vehicle is started? It does shut right off. Is this as part of update?

When did they start putting a DEF heater dash light on the trucks? I think all you have is a glow plug light.

 

Finally got my truck back, after having both the update done, as well as having the entire DEF tank assembly (with pump/heater/module/wiring harness,etc.) all included.

There is mention on this thread to be sure and have that update done, which was done...but what exactly is different about the update? Being an old techinical guy/mechanic myself, I'd like to know what parameters have been change, and what the difference is now? (IE: Less duty cycles of the heater....higher initial temp before it turns on...no speed limiting (we can only wish!), etc. )

Thanks in advance if anyone knows.

 

Have this problem with 2—2020 Silverado 3/4 ton pickups both with only 20000 miles was able to get part for 1 of them after 3 weeks unfortunately it is second generation part and the pins don’t match up to the truck now waiting for more back orders parts

 

Hello all, have a question about the def wiring harness for the heaters. I just bought a 2020 3500 Sierra Duramax. Only put 3000 miles on and got the dreaded service def system notice. Took it to dealer and they said the wiring harness torched itself. To top it off they said the part is back ordered and they can’t find one. Sent me off in a loner with no answer as to when it can get fixed. My question is has anyone else had this problem, I have heard of tank sensors and other crap going on but haven’t heard about the harness burning up. Any info would help thanks

We've had this happen twice in one winter on the diesel Chevy Equinox. Will have to look into a software update because this is the 5th time it's happened in 5 years. As far as I understand it uses the same parts that the trucks use.

 

Got the Equinox back from the dealer. They replaced the wiring harness for the second time this year. They said that there is no fix for the equinox because there isn't enough demand to justify a recall, so they said its likely just going to keep burning up.