3.0 Duramax cranks but won’t start

DVR · August 30, 2021

45 minutes ago, Greenman27 said:

Just updating everyone on the crank no start issue on my 21 Silverado. It has happened 3 times so far 1500 mi 4800 mi and 6070 miles. It has always been with a warm engine. it always starts second try perfect.

With less than 3500 km's our truck has had long crank/no start 5 times. The last one was a cold start in the morning. All were using push button start.

Claxy515 · August 30, 2021

Mine has happened on a warm engine and a cold one. Only thing in common was that I was in a hurry both times, pressing the brake and the start button at the same time. Foot definitely was not on the gas pedal. Normally, I press the button, put my foot on the brake, and press the button again to start. Never had an issue that way.

Camille · August 31, 2021

On 8/24/2021 at 3:58 PM, Joe Brooks said:

Has anyone has the “shim” installed on the cam shaft position sensor long enough to know if that fixed the issue?

I got my shim added a few weeks ago, just went on a 5 hour drive & back for a week long vaca with it but no issues as of yet....

Edited August 31, 2021 by Camille

Camille · August 31, 2021

On 8/30/2021 at 10:12 AM, macodi said:

Has anyone ever had the truck fail to eventually start after one or several of the long crank/no start issues? In other words it never started and you had to have it towed?

With mine, i would get the long crank/no start & would have to wait over an hour for it to finally start again. I would try multiple times to start it to the point where the battery almost died bc it wasn't starting. Both times the tow trucks were on their way/just arrived & then it finally would start with no issues.

DVR · August 31, 2021

1 hour ago, Camille said:

I got my shim added a few weeks ago, just went on a 5 hour drive & back for a week long vaca with it but no issues as of yet....

Hi Camille. Hopefully your truck had the 4 hour procedure to add the shim, and not the "cab off" method.

Frankhpns · August 31, 2021

There are two separate issues. 1. Camshaft position sensor reluctor wheel bent. 2. Camshaft position sensor shim installed. The TSB on either requires removal of camshaft cover. It is my understanding that the shim addition is added if the camshaft reluctor replacement does not fix the problem. The cab off procedure makes it easier to work on the engine. It is not mandatory.

Camille · August 31, 2021

1 hour ago, DVR said:

Hi Camille. Hopefully your truck had the 4 hour procedure to add the shim, and not the "cab off" method.

They got the shim on a monday & then it was ready by tuesday afternoon so i'm 99% sure they never took the cab off thankfully!

Barrett10 · August 31, 2021

1 hour ago, Frankhpns said:

There are two separate issues. 1. Camshaft position sensor reluctor wheel bent. 2. Camshaft position sensor shim installed. The TSB on either requires removal of camshaft cover. It is my understanding that the shim addition is added if the camshaft reluctor replacement does not fix the problem. The cab off procedure makes it easier to work on the engine. It is not mandatory.

See previous post and pictures, they removed my front end and took the motor out… but thank goodness, GM is going to re-purchase/reimburse me for my truck.

Joe Brooks · August 31, 2021

I thought I read earlier someone left their truck with the dealer to drive to see if they could replicate the problem with a computer hooked to it. Was there ever a response posted as to what they found? How many have had the shim installed? I see Camille with no issues yet. Anyone else?

Edited August 31, 2021 by Joe Brooks

Gruggas · August 31, 2021

I’m getting a shim installed currently. Will update if there is any issues.

Joe Brooks · August 31, 2021

Dang Gruggas. Is this the same truck that got the exciter wheel replaced? I thought they were buying yours back. Just got done with my first oil change and got an ecm update. I’m sure I’ll be back at the dealer soon.

Edited August 31, 2021 by Joe Brooks

fireaxxe · August 31, 2021

Just picked mine up from the dealership and was informed that they were able to recreate the crank no start issue and they “fixed” the problem. I was then told they updated the software and instantly my excitement faded away. They also did something to the regen cycle. It was in regen on the way home and I heard no knocking. In my state it takes 4 repair attempts and 20 days at dealership for the same issue to use lemon law, so one down 3 to go. Due to the fact that I am interested in a buyback I have to record every time I hit the start button for proof. Will post updates.

GJR1212 · September 1, 2021

12 hours ago, fireaxxe said:

Just picked mine up from the dealership and was informed that they were able to recreate the crank no start issue and they “fixed” the problem. I was then told they updated the software and instantly my excitement faded away. They also did something to the regen cycle. It was in regen on the way home and I heard no knocking. In my state it takes 4 repair attempts and 20 days at dealership for the same issue to use lemon law, so one down 3 to go. Due to the fact that I am interested in a buyback I have to record every time I hit the start button for proof. Will post updates.

Did they say what they did to correct the regen knocking?

WontStart · September 2, 2021

I just had the no-start happen repeatedly in a parking lot. I disconnected the battery for a little bit and the truck started right up after reconnecting.

Edited September 2, 2021 by WontStart

Phoenix959 · September 2, 2021

I have 6K on my truck and have had the issue about 10-12 times... Never on auto restart. To me it seems like the firmware is not starting the fuel flow but the starter engages, the next time you hit the button fuel flows and all is well but the dealer can't reproduce so they say it's in my head.