3.0 Duramax cranks but won’t start

WontStart · October 5, 2021

I finally got the invoice from my dealer. It says that they replaced the “run/crank relay” PART#: 13500114

Maybe this is related to the part shortage that caused GM to temporarily stop production of this motor.

GJR1212 · October 5, 2021

2 hours ago, WontStart said:

I finally got the invoice from my dealer. It says that they replaced the “run/crank relay” PART#: 13500114

Maybe this is related to the part shortage that caused GM to temporarily stop production of this motor.

Googled that part number. It is a pretty genaric relay of the type used to isolate the higher current load circuit from the lower current control circuit. It is a $10.20 part. I can't see how it could be related to the parts shortage since almost any GM suppliers of electronics could make this part.

gemarsh · October 6, 2021

5 hours ago, WontStart said:

I finally got the invoice from my dealer. It says that they replaced the “run/crank relay” PART#: 13500114

Maybe this is related to the part shortage that caused GM to temporarily stop production of this motor.

Huh, that is a compressor relay, used back from the mid 90's!

There are gobs of them around.

WontStart · October 6, 2021

The guys at the dealership seemed pretty confident the problem was a bad relay. The invoice said the factory relay was tested and found to be “sticking”. Time will tell I guess.

krillab · October 6, 2021

I just took mine in and they applied "PIP5823b" to flash the ecm. It cranks for about a second longer now when you start the engine, but it starts. If I have issues after this I'll reply back here. This is the only fix I've tried - I avoided all of the stuff with the shim.

christopher jhill · October 6, 2021

glad to see im not the only one. Have a 21 denali carbon pro, its done this 2 times....once at 800 miles, other at 2100. Nothing since. Been into the dealership twice and they cant figure it out. Going back in friday for tonneau cover install. Guess we will see. its just 80grand right?

redwngr · October 7, 2021

From krillab's post, it's already the PIP has already been updated to version 5823B,

but it seems to apply to all 20 and 21 LM2

-- lifted from another site --

Edited October 7, 2021 by redwngr

macodi · October 8, 2021

Made appt by phone at dealership to get 1st oil/filter change and discussed the long crank/no start issue and gave her PIP5823b. Arrived at dealer and reminded her of the long crank/no start issue with a great audible description. They called 4 hrs later stating truck was ready. She indicated that the tech said PIP5823b did not apply and he could not recreate the problem. Got in truck and read the ticket.

"Customer states vehicle intermittently shuts off. Technician found no trouble."

Bouncing somewhere between laugh and cry.

Scot Demmer · October 9, 2021

2021 At4 same issue always starts on second try for now. This has happened 4 times no codes and service advisors always play dumb.

Murph303 · October 9, 2021

On my second 2021 3.0 Sierra with crank no start issues. First truck was taken back by dealership with x1 episode after reading this forum. Second truck same model has had x3 episodes now. Was scoped after second episode to diagnose bent Wheel. Wheel was not bent and shim installed. Yesterday was the 3rd episode of crank no start and will be getting pip5823A performed this Monday. Also mentioned the relay part and was told national back order but has one ordered. Everybody that is getting this service done needs to update this forum every 300-500mi or so we have paper tail for the dealerships. My dealership didn’t even know about the recent pip and it was bc of this forum I made them aware. Guys/gals it’s power in numbers that gets this fixed. I’ll update after my fix if it fails before the mi mark. Also I was in a hurry each time not hitting button first then brake to button sequence. Starts second try every time. Ttyl

WontStart · October 9, 2021

4 hours ago, Murph303 said:

On my second 2021 3.0 Sierra with crank no start issues. First truck was taken back by dealership with x1 episode after reading this forum. Second truck same model has had x3 episodes now. Was scoped after second episode to diagnose bent Wheel. Wheel was not bent and shim installed. Yesterday was the 3rd episode of crank no start and will be getting pip5823A performed this Monday. Also mentioned the relay part and was told national back order but has one ordered. Everybody that is getting this service done needs to update this forum every 300-500mi or so we have paper tail for the dealerships. My dealership didn’t even know about the recent pip and it was bc of this forum I made them aware. Guys/gals it’s power in numbers that gets this fixed. I’ll update after my fix if it fails before the mi mark. Also I was in a hurry each time not hitting button first then brake to button sequence. Starts second try every time. Ttyl

I have one of the trucks that had the above mentioned relay replaced. Just for poops and laughs I removed that relay and tried starting the truck… it still started. I’m not convinced that relay has anything to do with it.

nvm I had pulled the wrong one. It didn’t start.

Edited October 9, 2021 by WontStart

youcantkeepup! · October 11, 2021

I had the pip5823b done about 300 miles ago. So far so good. As everyone who has had it done states, it cranks over a hair longer then it used to but it has started every time. I don't even second guess or think about it not starting anymore

GJR1212 · October 11, 2021

On 10/9/2021 at 1:52 PM, WontStart said:

I have one of the trucks that had the above mentioned relay replaced. Just for poops and laughs I removed that relay and tried starting the truck… it still started. I’m not convinced that relay has anything to do with it.

nvm I had pulled the wrong one. It didn’t start.

My truck has three of those same relays in the underhood fuse box. One for start, one for the headlights, and one for running lights. If someone wants to see if it the relay, just rotate it with one of the ones doing light duty. It pretty easy to tell if your lights still work. My guess is your dealer didn't know what to change so they changed the cheapest part they could find. These relays sell for about $10 from GM OEM dealers. Dealers seem lost when it comes to troubleshooting this problem.

I wish GM would explain what they changed in the ECU program. My guess is they are adding some time delays to give the ECU time to see all the inputs in what is likely a long list of parameters. Or, perhaps they are just giving the fuel pump and little extra time to spool up.