Won't start ?

TX-silveraldo · May 14, 2021

This just happened to me. New 2021 Silveraldo. 5000 miles. 1 mile from public road. Started up sputtered and died. Tried a half dozen times with the same result. Start up sputter and die. After an hour wait it started. When it did I heard a big clunk that sounded like the transmission dropped. Got a diagnostic report saying to get engine and transmission checked and the check engine light came on. It stayed on for 4 hours on my drive home. Started it up to take it to the dealer and the check light is off. Take it in tomorrow to see what dealer says.

Dirk13 · May 14, 2021

8 hours ago, Jmartin2 said:

Anyone experience a permanent fix with this issue? My truck has the 3.0 duramax and I’m wondering if it’s potentially a different issue. Almost seems like the truck isn’t getting fuel while attempting to start. Always stars on the second attempt and never throws a code (which makes it real fun when dealing with technicians).

Have you tightened the fuse box bolts to the proper torque yet?

I had this happen to me one time at 1250 miles. Checked the bolts and they were far from what they were specified to be torqued to in the service bulletin. I find it hard to believe that GM has not been able to correct this issue on the assembly line in 2-3 years. Something this simple that causes such a big impact you would think they would take care of. Im not saying this is the root cause of the crank and no start but I have not had the issue again in the last 1000 miles. It is worth trying.

Not sure if it is related or not but before I torqued the bolts, I noticed the voltage gauge on the dash showing 12ish a lot while driving. Since torquing, I’ve never seen it down there again. It’s always 14 or slightly above.

2021 3.0 Silverado

Jmartin2 · May 15, 2021

10 hours ago, Dirk13 said:

Have you tightened the fuse box bolts to the proper torque yet?

I had this happen to me one time at 1250 miles. Checked the bolts and they were far from what they were specified to be torqued to in the service bulletin. I find it hard to believe that GM has not been able to correct this issue on the assembly line in 2-3 years. Something this simple that causes such a big impact you would think they would take care of. Im not saying this is the root cause of the crank and no start but I have not had the issue again in the last 1000 miles. It is worth trying.

Not sure if it is related or not but before I torqued the bolts, I noticed the voltage gauge on the dash showing 12ish a lot while driving. Since torquing, I’ve never seen it down there again. It’s always 14 or slightly above.

2021 3.0 Silverado

Yeah I’ve tighten the bolts and check all the other connections while I was in there. I probably did that about 1000 miles ago and it’s happened 2 more times since then. So I’m not very hopeful that’s my issue. Truck goes in to dealership next week so we will see

Dirk13 · May 15, 2021

2 hours ago, Jmartin2 said:

Yeah I’ve tighten the bolts and check all the other connections while I was in there. I probably did that about 1000 miles ago and it’s happened 2 more times since then. So I’m not very hopeful that’s my issue. Truck goes in to dealership next week so we will see

best of luck with it. Please post back with what they do and if you get a solution.

singlespeed · May 15, 2021

12 hours ago, Jmartin2 said:

Yeah I’ve tighten the bolts and check all the other connections while I was in there. I probably did that about 1000 miles ago and it’s happened 2 more times since then. So I’m not very hopeful that’s my issue. Truck goes in to dealership next week so we will see

Bummer... It's crazy GM doesn't have a fix for this yet that dealers know about it. Please keep us updated.

Storti · May 16, 2021

That bulletin posted in this thread isn't the fix or relative for this issue if anyone actually read it. First thing it says is "-won't crank" which isn't why we are on this thread. This thread is for crank but no start.

Now GM, just think if this happens at an intersection with the tree hugging auto engine off feature engaged.

Anyway, so I just spent 60k on a 21 GMC Sierra AT4 a month ago and the crank no start issue happened with 300 miles on it and now with 1100 miles on it. Second try it'll start, as of now, this might change but who knows at this point.

Doesn't sound like anyone has had luck with this issue yet and I'm sure GM has no clue, they'll probably say it has covid. Anyway I will be monitoring the thread, Thanks for reading.

Rob Mugs · May 16, 2021

I had this happen with ~2k miles on the odo. As was the issue with another guy here, I had just gotten back from washing the truck.

Floormat wasn't in correctly and was pressing the accelerator pedal.

I know it's not always the cause but one that seems somewhat overlooked in this post

Jmartin2 · May 16, 2021

6 hours ago, Rob Mugs said:

I had this happen with ~2k miles on the odo. As was the issue with another guy here, I had just gotten back from washing the truck.

Floormat wasn't in correctly and was pressing the accelerator pedal.

I know it's not always the cause but one that seems somewhat overlooked in this post

The factory floor mats (or any aftermarket laser fit mat) will have the alignment cut outs in them so they snap in place to keep the floor mat from sliding around. I have the factory Z71 mats (which are snap in place fit), and I’m still experiencing this issue. I’m curious if you have mats that are the same. Weather tech, husky, or some off brand that just slides around? I’ve looked mine over and there really isn’t any room for the thing to slide up on the accelerator pedal. I’ve also never taken mine out of the truck since purchasing it.

khays · May 30, 2021

On 5/14/2021 at 2:43 PM, TX-silveraldo said:

This just happened to me. New 2021 Silveraldo. 5000 miles. 1 mile from public road. Started up sputtered and died. Tried a half dozen times with the same result. Start up sputter and die. After an hour wait it started. When it did I heard a big clunk that sounded like the transmission dropped. Got a diagnostic report saying to get engine and transmission checked and the check engine light came on. It stayed on for 4 hours on my drive home. Started it up to take it to the dealer and the check light is off. Take it in tomorrow to see what dealer says.

This sounds wildly different (worse) than what I think most of the other posters here were experiencing..

Dogdad · June 1, 2021

Had my 21 Sierra with 1200 miles towed to the dealer Saturday because of the non start issue. However, Saturday night I got on this forum and read through the post. One thing that stuck out to me was the few post regarding floor mats causing the issue. It just so happens that Saturday afternoon after enjoying a couple of cigars, I came out to my truck and pulled out my floor mat ( GMC) to shake it off. After installing the floor mat and getting in my truck is when it wouldn’t start. So I got to the dealer earlier this morning and went and looked at my floor mat. Well damn, it was covering the gas pedal. I corrected it and started right up.. with me laughing and shaking my head. I told the shop foreman this and he laughed. It wasn’t the first time he’s seen this. He said you can’t press on the gas pedal when starting as it shuts down the fuel pump.. a GMC safety feature. So check your mats and make sure you’re not pressing on the gas pedal while starting.

Dogdad · June 1, 2021

On 5/15/2021 at 9:54 PM, Rob Mugs said:

I had this happen with ~2k miles on the odo. As was the issue with another guy here, I had just gotten back from washing the truck.

Floormat wasn't in correctly and was pressing the accelerator pedal.

I know it's not always the cause but one that seems somewhat overlooked in this post

No more start issues since the floor mat causing it?

Dogdad · June 1, 2021

On 12/23/2019 at 12:51 PM, Icefisher said:

I am embarrassed to report my issue was operator error.

When I was washing my truck, I cleaned the Weather-Tech Floor mats. When I reinstalled them, I accidentally covered the accelerator pedal. By doing this, the vehicle will turn over but will not fire.

I didn't feel too bad, because it took the tech 5hrs to find the issue as well. My dealer was really cool, and did not charge me a dime for the issue.

Any more issues since the floor mat correction?

Jmartin2 · June 1, 2021

3 hours ago, Dogdad said:

Any more issues since the floor mat correction?

How are you guys installing your floor mats incorrectly? They literally have alignment holes recessed in them to affix them to the pin that’s on the floor of the truck. I can assure you that this was just a fluke. There are several TSB’s out on this issue, you’ll want to have them handy next time your dealer has the truck.

Dogdad · June 2, 2021

41 minutes ago, Jmartin2 said:

How are you guys installing your floor mats incorrectly? They literally have alignment holes recessed in them to affix them to the pin that’s on the floor of the truck. I can assure you that this was just a fluke. There are several TSB’s out on this issue, you’ll want to have them handy next time your dealer has the truck.

Slipped the mat in front of the gas pedal by not paying attention. If it’s a fluke , I have no problem reposting that the issue happened without the floor mat scenario.

Dogdad · June 2, 2021

New 21 with 1200 miles. Had to have it towed in the dealership. Shop foreman thinks it’s fuel related but won’t look at it till tomorrow. Video of what it’s doing and I’m assuming this is what most are experiencing? ……..

I made a video with the floor mat keeping the truck from starting. This site won’t let me post it…but if you start your truck with foot on brake and gas pedal down…same effect.