3.0 Duramax cranks but won’t start

macodi · September 10, 2021

I'd be willing to try that, but would likely forget about as much as I do turning off the "auto off/on" button.

Barrett10 · September 10, 2021

23 minutes ago, macodi said:

I'd be willing to try that, but would likely forget about as much as I do turning off the "auto off/on" button.

Did it both ways. While in the cab and walking towards the truck with the key fob, it didn’t matter still had episodes. It didn’t matter still had episodes both ways, no start with fob and in the cab with the push button.

coinman · September 11, 2021

Happend to me, first time. 1881 miles at 6 am with fob remote start. Heard it just cranking away as I walked up to it. I immediately hit the remote start again, and it stopped. Sat inside and hit the button and started right up..

My build date is 6/5/21

Edited September 11, 2021 by coinman
Added build date

macodi · September 11, 2021

Having the issue now. 5 no starts in the last 30 mins. Never failed to start before, but not looking good. Chk eng lite on, but last time that happened it didn't produce a code Did something odd that hadn't happened before. After the 2nd no start I waited a couple mins and tried the fob remote start. Wouldn't do anything and tried it twice. No lights flash, nothing. After a couple mins remote start did the no start. Leaving for 650 mile trip Wed and not feeling so confident.

macodi · September 12, 2021

Watched football for about 30 mins and went out to try it again. Started right up on try #6. Gremlin.

GJR1212 · September 12, 2021

3 hours ago, macodi said:

Having the issue now. 5 no starts in the last 30 mins. Never failed to start before, but not looking good. Chk eng lite on, but last time that happened it didn't produce a code Did something odd that hadn't happened before. After the 2nd no start I waited a couple mins and tried the fob remote start. Wouldn't do anything and tried it twice. No lights flash, nothing. After a couple mins remote start did the no start. Leaving for 650 mile trip Wed and not feeling so confident.

You should at least get the code read at an auto parts store, if you do have a code reader, before you head out on a long trip.

macodi · September 12, 2021

I did that and although chk eng lite was on, it did not throw a code.

DALBY · September 13, 2021

HELLO GENTLEMAN'S, I WAS HAVING THIS SAME PROBLEM AND I BELIEVE I FOUND THE ISSUE AN A POSSIBLE INTERIM SOLUTION. WHEN THE START SWITCH PUSH BOTTOM IS SELECTED, THE ELECTRICAL CIRCUIT FOR THE ELECTRICAL STARTER WILL BE INITIATE FASTER THAN THE TIME THAT IT TAKES FOR THE COMPUTER TO BOOT UP TO AND TAKE CONTROL OF THE STARTING SEQUENCES, HOW DO I KNOW THAT!! BECAUSE IF YOU PUSH THE START BUTTON FIRST WITHOUT PUSHING THE BRAKE PEDAL, WAIT FOR 2 SECOND AND THEN PUSH THE PEDAL AND THE START BUTTON IT WILL WORK EVERY TIME.

I HOPE THIS HELP. I WAS HAVING THIS PROBLEM CONSTANTLY ALMOST EVERY DAY, AND FOR THE LAST 4 MONTHS I HAVEN'T HAD ANY ISSUES.

GM MUST FIX THIS ISSUE.

Hello32 · September 14, 2021

Dropped off my truck at the dealer for the shim. Got a call from a lemon law attorney I have used in the past while i was waiting for a rental. Guess it wasn't meant to be, signed all the paperwork and got the process started.

GJR1212 · September 14, 2021

On 9/12/2021 at 11:19 PM, DALBY said:

HELLO GENTLEMAN'S, I WAS HAVING THIS SAME PROBLEM AND I BELIEVE I FOUND THE ISSUE AN A POSSIBLE INTERIM SOLUTION. WHEN THE START SWITCH PUSH BOTTOM IS SELECTED, THE ELECTRICAL CIRCUIT FOR THE ELECTRICAL STARTER WILL BE INITIATE FASTER THAN THE TIME THAT IT TAKES FOR THE COMPUTER TO BOOT UP TO AND TAKE CONTROL OF THE STARTING SEQUENCES, HOW DO I KNOW THAT!! BECAUSE IF YOU PUSH THE START BUTTON FIRST WITHOUT PUSHING THE BRAKE PEDAL, WAIT FOR 2 SECOND AND THEN PUSH THE PEDAL AND THE START BUTTON IT WILL WORK EVERY TIME.

I HOPE THIS HELP. I WAS HAVING THIS PROBLEM CONSTANTLY ALMOST EVERY DAY, AND FOR THE LAST 4 MONTHS I HAVEN'T HAD ANY ISSUES.

GM MUST FIX THIS ISSUE.

I have wondered whether the fact that GM has been short processors if they have lowered their acceptance standards for ECU chips. A substandard chip would be slower than expected. Modern chips are really faster than we are at tripping switches. The designers probably assume this. Assuming you are correct that the ECU is loosing the relay race, it should be easy for GM to add logic to wait for all required automatic actions to complete before starting the cranking. Also, they should shorten the cranking to something like 4 seconds instead of 20 or 30 as it is now.

About half the time I hit the button before remembering to step on the brake. So, I have been pretty much following you method. I've have had only one long start. Hope some other folks with frequent long starts will try your method and report if they still have long starts.

Claxy515 · September 14, 2021

7 hours ago, GJR1212 said:

I have wondered whether the fact that GM has been short processors if they have lowered their acceptance standards for ECU chips. A substandard chip would be slower than expected. Modern chips are really faster than we are at tripping switches. The designers probably assume this. Assuming you are correct that the ECU is loosing the relay race, it should be easy for GM to add logic to wait for all required automatic actions to complete before starting the cranking. Also, they should shorten the cranking to something like 4 seconds instead of 20 or 30 as it is now.

About half the time I hit the button before remembering to step on the brake. So, I have been pretty much following you method. I've have had only one long start. Hope some other folks with frequent long starts will try your method and report if they still have long starts.

I agree with Dalby says. All 3 times mine has done it, I've been in a hurry. People keep saying that there is no pattern, but clearly some of us are paying more attention and noticing this pattern. An update to our software to prevent this would be the ultimate fix, but we'll have to see what GM does/finds. We could be completely wrong. But kudos to you and Dalby, along with myself for thinking about this scenario.

krillab · September 15, 2021

13 hours ago, Claxy515 said:

I agree with Dalby says. All 3 times mine has done it, I've been in a hurry. People keep saying that there is no pattern, but clearly some of us are paying more attention and noticing this pattern. An update to our software to prevent this would be the ultimate fix, but we'll have to see what GM does/finds. We could be completely wrong. But kudos to you and Dalby, along with myself for thinking about this scenario.

It happened to me for about the fifth time yesterday evening, but I was using my remote start. I doubt my truck knew that I was in a hurry using the remote start.

bdallas · September 15, 2021

I just had my third long crank, no start at just under 5K miles.

First was just under 100 miles, then around 2K.

Barrett10 · September 15, 2021

1 hour ago, krillab said:

It happened to me for about the fifth time yesterday evening, but I was using my remote start. I doubt my truck knew that I was in a hurry using the remote start.

It makes no difference if you use the remote or the push button. There is no pattern at all. I man getting reimbursed for my full amount within two days. The truck is still in the shop, they put the motor back together with the new shim and reluctor wheel, and now it just turns over and won’t start. They’re having a GM engineer come look at it again. Thank goodness that’s not my truck anymore.