2021 Duramax issues, less than a week old.

[Joe_Lee]

Purchased Tuesday 12/22/20.

Day 3 of ownership 12/24 - rained overnight and leaking back glass with service appointment scheduled for Monday.

Day 5 of ownership 12/26 - at 361 miles - check engine light, text from onstar and email that vehicle must be serviced within 7 days - code P026C.

 

I hope this is not a sign of things to come for sure.

[Chris2087]

Fuel injection quantity – quantity lower than expected

[Booger T]

16K trouble free miles to date. Took delivery  1-2-20

[In2racn]

Mine sits waiting for parts - P20C1, DEF tank heater. 20K miles. This is the second CEL with limp mode warnings.

 

Edited December 28, 2020 by In2racn

[Njmurvin]

In 1450 miles of ownership:

 

I had a slight DEF leak. They replaced the DEF injector and while in the service bay, they noticed and fixed an engine oil leak at the oil filter adapter. They replaced the adapter. No leaks now.

 

My only remaining issue is a rattle in the dash when first started up (cold engine). It goes away in about a minute of driving. I haven't taken it in for that one yet. It's a known issue (on the Duramax forum).

[SD Local]

Same issue here, I’ve got a 2021 - 3500 duramax. Same code - keep me posted please

[Andrew Reeves]

At 315 mile CEL came on with error code P026C (Chevy 3500). Took it to the GM dealership the next day. They said this was a known issue and GM was investigating. They cleared the code and sent me on my way. Within a few hours, the CEL came back on. Frustrating....apparently this is a common issue with the Chevy 2500/3500's and GMC 2500/3500's.

[K3500WT]

My 2021 Chevy 3500 Dmax has had check engine code PO26C started at 4K miles now passing 6k. Dealer can’t fix it. Also displaying PO22FB and P2AOO codes now. Already had it in the shop 3 times for this. Loss of time and couldn’t tow anything for 2 weeks so far this year. I’m very grateful for their little loaner cars but they don’t  replace a one ton work truck.

[AJ57]

Has anyone had this recurring P026C check engine code resolved yet?  Have a 2021 GMC Sierra 3500 Dmax as well that was purchased out of state due to no inventory in CA...threw a code on the way home to CA and now it can't be registered in CA due to smog requirement.  Spent $80k + on a truck that can't be registered.  I have GM case number assigned but getting ahold of anyone at GM is nigh to impossible.

[jl374]

check #20-NA-197:  this notice is for several trouble codes, fuel pressure sensor connnector may be poor connection.

good luck. 

[K3500WT]

On 4/2/2021 at 2:26 PM, Andrew Reeves said:

At 315 mile CEL came on with error code P026C (Chevy 3500). Took it to the GM dealership the next day. They said this was a known issue and GM was investigating. They cleared the code and sent me on my way. Within a few hours, the CEL came back on. Frustrating....apparently this is a common issue with the Chevy 2500/3500's and GMC 2500/3500's.

 

8,500 miles and my CEL is still on. PO26c. Corporate and the Dealer are just passing the buck back and forth. I may call in a Lemon Law Attorney and then try a different brand. Only possible during the first year of ownership! After that you’re at the mercy of GM. They don’t seem to care what happens.