Code P0402

[dz302]

Picked up my 2024 chevy 2500 duramax with the bison package. Less than 300 miles and engine light came on, truck is doing all types of crazy shifting and major hesitation etc….OnStar tells me it’s an engine emissions issue. do not drive, seek immediate resolution. Anyone have this issue or any insight into what the issue is…nearly 100k and already issues. Disappointed in my new Chevy.

 

[ZR2NYC]

Picked up my 2024 chevy 2500 duramax with the bison package. Less than 300 miles and engine light came on, truck is doing all types of crazy shifting and major hesitation etc….OnStar tells me it’s an engine emissions issue m do not drive, seek immediate resolution. Anyone have this issue or any insight into what the issue is…nearly 100k and already issues. Disappointed in my new Chevy.

EGR excessive flow. emmissions related. that really sucks. dealer should immediately repair. good luck.

 

[AXE]

Usually that code is for a bad or dirty EGR valve and can also be caused by dirty intake manifold. That's usually with higher mileage vehicles. I'm guessing you might have a bad part as it wouldn't be dirty with low mileage.

It you ain't getting the right regulated air and fuel flow, you'll get those symptoms of poor motor performance and shifting.

Of course there are so many damn emissions components and computers on these new trucks it could be anything up stream or downstream of EGR.

Check the Duramax Forums. I'm pretty sure I seen someone else post a similar issue.

Hopefully it's fixed fast. Emissions issues are sometimes hard to diagnose on these trucks. My only real issue with a Duramax was DEF sensor and 9th injector, both emissions components.

 

[dz302]

I bring it in to the dealership Friday morning first thing. I’ll keep you all posted on what they find. It concerns me being so new And all. Hope it’s not one of those issues that are chased after for years…..I need my truck to be reliable like Everyone else I suppose…thanks for the reply’s

 

[AXE]

Historically, these Duramax trucks have been very reliable. With all the new electronics, there's a lot of room for issues. These emission systems haven't been great for 12 years.

I've had plenty of niggling electronic issues (nothing major) with my 22 1500 ZR2 and the 2500 ZR2 seems to have some of the same, but I do feel like it's been a little better. I've only got 300 miles, so too early to tell. Mechanically, these trucks should be solid.

 

[wutang61]

My 22 has has more than its share of electrical bugs and glitches. Most if not all have been remedied by module updates.

The truck would do some crazy things when it was new. It’s probably been to the dealer 8 times since I’ve bought it. For varies module reflashes. A new radio, FPDM, 3 clusters later it seems to have sorted out. The last stint required me going postal to get the thing fixed. First and last time at that dealership where it was towed. Wouldn’t piss on it to put it out.

The latest revisions to software and hardware are much more ironed out. But hey, that’s the gamble you take buying a 1st year of any vehicle.

If you have a good relationship with your dealer they will take care of you. Good luck with the fix.

 

[ZR2NYC]

My 22 has has more than its share of electrical bugs and glitches. Most if not all have been remedied by module updates.

The truck would do some crazy things when it was new. It’s probably been to the dealer 8 times since I’ve bought it. For varies module reflashes. A new radio, FPDM, 3 clusters later it seems to have sorted out. The last stint required me going postal to get the thing fixed. First and last time at that dealership where it was towed. Wouldn’t piss on it to put it out.

The latest revisions to software and hardware are much more ironed out. But hey, that’s the gamble you take buying a 1st year of any vehicle.

If you have a good relationship with your dealer they will take care of you. Good luck with the fix.

good statement WU!!! feeling same. i waited selling dealer out of 5k market adjustment for 6 months. nobody even blinked at my rig but me!!! my ZR2 isnt as buggy as yours but it has its hickups. same infotainment drops never fixed with 2 visits. DIC not updated with a 2 hour attempt that failed and the dreaded jack-n-the box lifter fail. that said, i love my truck! its got balls and i get compliments at every fillup. Borla did right by me and im proud my trip econ hovers at about 8.9 gallons.

 

[AXE]

Wutang, I'm curious with your clusters replaced did you get different icons in the infotainment menu screens? My 24 seems to have a few revised images. Haven't really done a detailed comparison, but seems as though there were a few changed.

 

[dz302]

Just got home from the dealership. There is a technical service bulletin for the exact issue I was having, (P0402). The tech reprogrammed the ECM and I was on my way home. Drove for over an hour with no issues, averaged 20.2 miles per gallon through the hills of Pa. Crossed fingers that is all she wrote for that issue. P0402 solved for now.

 

[AXE]

Just got home from the dealership. There is a technical service bulletin for the exact issue I was having, (P0402). The tech reprogrammed the ECM and I was on my way home. Drove for over an hour with no issues, averaged 20.2 miles per gallon through the hills of Pa. Crossed fingers that is all she wrote for that issue. P0402 solved for now.

I think that was similar to the other issue I had seen someone post. If there's a TSB, it's more than likely the only issue and the fix will be good.

Too many electronics to be reliable. Need to roll the clocks back to 2005.

 

[ZR2NYC]

Just got home from the dealership. There is a technical service bulletin for the exact issue I was having, (P0402). The tech reprogrammed the ECM and I was on my way home. Drove for over an hour with no issues, averaged 20.2 miles per gallon through the hills of Pa. Crossed fingers that is all she wrote for that issue. P0402 solved for now.

well done. thanks for update.