P0201 and P0301 Cylinder 1 Misfire

bruss

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2022 ZR2 1500. 8200 Miles. Kind of a long read but need help!

Today was an interesting day. I drove the truck over 800 miles yesterday to see family in a different state without a hitch and then this morning I remote start the truck, made it about a block and the cluster lit up like a Christmas tree. “Service ECS”, “Collision Avoidance Unavailable”, and “Service Traction Control”. CEL was blinking and the truck had a very harsh idle and steady misfire under acceleration. Limped to the local parts store and found P0301 and P0201 for Cylinder 1 misfire. Unplugged the coil pack on cylinder one and confirmed it was dead.

I disconnected the negative terminal on the battery and unplugged the main electrical connections on the air box and by the brake reservoir. Was hoping to find water or loose pins but everything looked fine and was dry.(Drove through 8 hours of rain yesterday) I then moved on to the fuse panels to verify everything was good. Other than a few not being fully seated, everything checked out. Slapped it all back together and truck still had the misfire.

Fast forward 30 minutes or so, hopped in the truck to move it and everything cleared up. Truck is running like a champ. WTF….. been driving it all evening and it seems fine.

I can only assume I am having harness issues on the engine harness. Anyone else have this intermittent issue? Super nervous right now as I am over 800 miles from home and need to trust this truck to get back! Local dealer support in the area is lacking at best and the closed rental car is an hour away.
 
2022 ZR2 1500. 8200 Miles. Kind of a long read but need help!

Today was an interesting day. I drove the truck over 800 miles yesterday to see family in a different state without a hitch and then this morning I remote start the truck, made it about a block and the cluster lit up like a Christmas tree. “Service ECS”, “Collision Avoidance Unavailable”, and “Service Traction Control”. CEL was blinking and the truck had a very harsh idle and steady misfire under acceleration. Limped to the local parts store and found P0301 and P0201 for Cylinder 1 misfire. Unplugged the coil pack on cylinder one and confirmed it was dead.

I disconnected the negative terminal on the battery and unplugged the main electrical connections on the air box and by the brake reservoir. Was hoping to find water or loose pins but everything looked fine and was dry.(Drove through 8 hours of rain yesterday) I then moved on to the fuse panels to verify everything was good. Other than a few not being fully seated, everything checked out. Slapped it all back together and truck still had the misfire.

Fast forward 30 minutes or so, hopped in the truck to move it and everything cleared up. Truck is running like a champ. WTF….. been driving it all evening and it seems fine.

I can only assume I am having harness issues on the engine harness. Anyone else have this intermittent issue? Super nervous right now as I am over 800 miles from home and need to trust this truck to get back! Local dealer support in the area is lacking at best and the closed rental car is an hour away.
merry christmas.....thats alot of info. could be a fluke or could be DFM malfunction. you need a reputable dealer diagnosis.
 
That’s my big hang up right now. I’m in the middle of podunk Kansas with no good dealer support close.

I am hoping someone has seen this issue already and can send some direction to look other than what I had listed above before I head back to TX here in a couple of days. I don’t trust it right now.
 
That’s my big hang up right now. I’m in the middle of podunk Kansas with no good dealer support close.

I am hoping someone has seen this issue already and can send some direction to look other than what I had listed above before I head back to TX here in a couple of days. I don’t trust it right now.
how about giving GM or Onstar a call???
 
2022 ZR2 1500. 8200 Miles. Kind of a long read but need help!

Today was an interesting day. I drove the truck over 800 miles yesterday to see family in a different state without a hitch and then this morning I remote start the truck, made it about a block and the cluster lit up like a Christmas tree. “Service ECS”, “Collision Avoidance Unavailable”, and “Service Traction Control”. CEL was blinking and the truck had a very harsh idle and steady misfire under acceleration. Limped to the local parts store and found P0301 and P0201 for Cylinder 1 misfire. Unplugged the coil pack on cylinder one and confirmed it was dead.

I disconnected the negative terminal on the battery and unplugged the main electrical connections on the air box and by the brake reservoir. Was hoping to find water or loose pins but everything looked fine and was dry.(Drove through 8 hours of rain yesterday) I then moved on to the fuse panels to verify everything was good. Other than a few not being fully seated, everything checked out. Slapped it all back together and truck still had the misfire.

Fast forward 30 minutes or so, hopped in the truck to move it and everything cleared up. Truck is running like a champ. WTF….. been driving it all evening and it seems fine.

I can only assume I am having harness issues on the engine harness. Anyone else have this intermittent issue? Super nervous right now as I am over 800 miles from home and need to trust this truck to get back! Local dealer support in the area is lacking at best and the closed rental car is an hour away.
Hey Bruss,

I had a similar issue, also while out of town. I had a cylinder 4 misfire that ended up being a faulty coil pack. Same screen info came up, same symptoms but I pressed the OnStar button and got an over air diagnostics report to confirm the issue and a copy emailed to me that I could send to my dealership. Now, I had two options, I could wait until a space was available at the nearest GM dealership (a Cadillac dealership that didn’t have a space available for over a week) or GM road service would tow my truck back to my dealership that had a space available immediately. Luckily I was only 70kms (45 miles) away from them, so the tow fee wasn’t too high (covered by GM roadside assistance) and I’m not too sure where the closest GM dealership is in proximity to you, but if it’s not too-too far I’m thinking they’ll tow it there if necessary and hopefully their garage has a space available immediately. If you can only get it serviced by your dealership, then make that argument and get them to ship you and your truck back to them. I hope this helps in any way and I hope this situation gets resolved quickly
 
Hey Bruss,

I had a similar issue, also while out of town. I had a cylinder 4 misfire that ended up being a faulty coil pack. Same screen info came up, same symptoms but I pressed the OnStar button and got an over air diagnostics report to confirm the issue and a copy emailed to me that I could send to my dealership. Now, I had two options, I could wait until a space was available at the nearest GM dealership (a Cadillac dealership that didn’t have a space available for over a week) or GM road service would tow my truck back to my dealership that had a space available immediately. Luckily I was only 70kms (45 miles) away from them, so the tow fee wasn’t too high (covered by GM roadside assistance) and I’m not too sure where the closest GM dealership is in proximity to you, but if it’s not too-too far I’m thinking they’ll tow it there if necessary and hopefully their garage has a space available immediately. If you can only get it serviced by your dealership, then make that argument and get them to ship you and your truck back to them. I hope this helps in any way and I hope this situation gets resolved quickly
Thank you for this info. I was unaware that the OnStar service could assist with trouble codes and getting a repair set up. This is my first GM in 20 years lol.

I’m glad to hear they will take care of us in shipping the vehicle and getting us back on the road.

I head back for tx in the morning. I have been driving the truck all over the area since this post and have not had any issues. *knock on wood*. We shall see what tomorrow brings!
 
I would probably be comfortable running it back home. If you're running through towns on major highways there will be a dealer close enough if things go bad.

I would have a code reader in my rig that can also clear codes to get moving again. I've got relatively cheap OBDLink bluetooth code readers from Amazon and run the TorquePro app as well as the OBDLink app.

You can always disconnect negative battery terminal for 5 minutes and see if problems resolved again.

Unfortunately, the electronics can be unreliable on these trucks. Seems like that is 90% of problem posts on this forum. Certainly higher problems than previous generation trucks.
 
I would probably be comfortable running it back home. If you're running through towns on major highways there will be a dealer close enough if things go bad.

I would have a code reader in my rig that can also clear codes to get moving again. I've got relatively cheap OBDLink bluetooth code readers from Amazon and run the TorquePro app as well as the OBDLink app.

You can always disconnect negative battery terminal for 5 minutes and see if problems resolved again.

Unfortunately, the electronics can be unreliable on these trucks. Seems like that is 90% of problem posts on this forum. Certainly higher problems than previous generation trucks.
Can you send me the info on the code readers and the app for your phone? I think I will invest in one for sure.

We typically take back country highways as it usually shaves quite a bit of time off of the trip but we will for sure be sticking to major highways this time.
 
I have these two, plus a corded one thar came with my Duramax Tuner. Original isn't that ugly green color tho, so it may have changed.

OBDLink MX+ OBD2 Bluetooth Scanner for iPhone, Android, and Windows https://a.co/d/9gsXkQP

OBDLink LX OBD2 Bluetooth Scanner for Android and Windows https://a.co/d/8vla5mb
 
And the saga continues… same problems flared up this weekend before the New Year plus a new one. I called my dealer immediately and have an appointment for 1/4. I will keep y’all updated as things progress.

Current issues I am having them diagnose and repair:
-cylinder misfire from injector control circuit
-starter just clicks/does not engage flywheel (new issue that just started) I forgot to push the button to kill the Auto start/stop and the truck would not restart in the middle of a busy intersection. Took 5 attempts before it cranked over and started.
-software update for the ZR2 display
-paint correction on hood from scoop rubbing
 
Here we are two weeks later and I finally got my truck back. Between my original service advisor quitting 3 days after dropping my truck off, getting the run around on actually getting my truck in the bay, dealership loosing parts and lastly a technician that didn’t show up for 2 days after having my truck in pieces I am not impressed with my dealership. They ended up replacing #1 injector and starter under warranty.

Side issue I tried to have them fix: Trailer running lights always on. Error on screen to check running lights on trailer while hooked up.
The technician “cleared the historical code” for my trailer light control module fault, ran truck, no codes present. (His report) Surprise surprise, trailer light still do not work properly. I told them the module was probably bad when I dropped it off but techs these days seem to only know how to plug a computer in and clear codes. The guy didn’t even verify if the voltage at the 7 pin was accurate. I spoke with the service manager and convinced him to order the module and just let me know when it gets there for them to install, I wasn’t leaving my truck. With the way this repair went, I’m still not sold it was just the injector that was bad. I’m hoping that I don’t have deeper harness issues and the tech just saw an issue with cylinder #1 fuel circuit so he threw an injector at it. Time will tell I guess.

I didnt even bother with them doing the paint correction on the hood or the screen update. Might find a different dealer.
 
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It's always a crap shoot. I've been working with the same dealer for 25+ years and they been pretty good. But I've had issues with my 22 and 24 and I am not sure they've fully been resolved either. My 24 HD need a new brake controller, but their trailer simulator says it's "ok". Waiting on a seat cover and homelink transmitter for 30 days.
 

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