[stickboy42]

Good day everyone,

I have had a flawless experience until today with my 16 z71 Duramax. Parked it at the store and came out to experience a no-start condition but it did crank.

After it was clear that the motor wasn't going to fire I did the following:

1) Disconnected both battery terminals to reset the ECM, waited 10+ minutes.
2) Checked engine bay fuse block, blown 7.5a Fuel Injectors - Odd - F09
3) Swapped fuse
4) Engine started fine

Blown fuses concern me, easy to change, but why it blew is of concern. There seems to be little online about this condition other than a few mentions of grounding out. I've checked wiring with no obvious issues and the truck has started 10+ times without issue. I don't have access to reading any DTCs right now but there are no indicator lights showing anything out of normal and the truck operates like new.

Any ideas or people who have had this happen before?

It's interesting to note that the blown fuse, F09 - Fuel Injectors Odd is 7.5a and the F08 - Fuel Injectors Even is a 15a. There must be something going on that I'm not seeing. Also interesting is that all models except the diesel (LWN) have matching 15a fuses.

Thanks in advance for any ideas,

Mike

 

[White016]

Good day everyone,

I have had a flawless experience until today with my 16 z71 Duramax. Parked it at the store and came out to experience a no-start condition but it did crank.

After it was clear that the motor wasn't going to fire I did the following:

1) Disconnected both battery terminals to reset the ECM, waited 10+ minutes.
2) Checked engine bay fuse block, blown 7.5a Fuel Injectors - Odd - F09
3) Swapped fuse
4) Engine started fine

Blown fuses concern me, easy to change, but why it blew is of concern. There seems to be little online about this condition other than a few mentions of grounding out. I've checked wiring with no obvious issues and the truck has started 10+ times without issue. I don't have access to reading any DTCs right now but there are no indicator lights showing anything out of normal and the truck operates like new.

Any ideas or people who have had this happen before?

It's interesting to note that the blown fuse, F09 - Fuel Injectors Odd is 7.5a and the F08 - Fuel Injectors Even is a 15a. There must be something going on that I'm not seeing. Also interesting is that all models except the diesel (LWN) have matching 15a fuses.

Thanks in advance for any ideas,

Mike

I have seen fuses blow for no apparent reason. Doesn't happen very often but it does. My theory is they are just bad, defective. Maybe your 7.5 was really more like a 3 amp so it finally let go. I think all you can do is look it over real good and see what happens. That is very odd about the 7.5 and 15. Can you look at the wiring diagram and figure out the difference?

oh, and carry some spares so you don't get stranded

 

[Chuck_B]

Take a look at the electrical upfitters manual.

The fuses are named Fuel Injectors Odd and Even but they feed more than that. On the gas trucks they feed ignition coils as well as mysteriously disappearing into the ECU.

On the diesel they just mysteriously disappear into the ECU.

Anyway - lack of ignition coils is a good start toward explaining the difference.

The signals at the ECU connector are just named main fused power 2 and 3 or something to that effect.

 

[Emil mehovic]

Good day everyone,

I have had a flawless experience until today with my 16 z71 Duramax. Parked it at the store and came out to experience a no-start condition but it did crank.

After it was clear that the motor wasn't going to fire I did the following:

1) Disconnected both battery terminals to reset the ECM, waited 10+ minutes.
2) Checked engine bay fuse block, blown 7.5a Fuel Injectors - Odd - F09
3) Swapped fuse
4) Engine started fine

Blown fuses concern me, easy to change, but why it blew is of concern. There seems to be little online about this condition other than a few mentions of grounding out. I've checked wiring with no obvious issues and the truck has started 10+ times without issue. I don't have access to reading any DTCs right now but there are no indicator lights showing anything out of normal and the truck operates like new.

Any ideas or people who have had this happen before?

It's interesting to note that the blown fuse, F09 - Fuel Injectors Odd is 7.5a and the F08 - Fuel Injectors Even is a 15a. There must be something going on that I'm not seeing. Also interesting is that all models except the diesel (LWN) have matching 15a fuses.

Thanks in advance for any ideas,

Mike

Hi Main
Did y figure out what’s wrong with your car
I have same issue will happen sometimes once in month sometimes less
Went to bunch mechanics but when I go there problem will not show up
Thanks in advance
Emil

 

[PatrioticSheepdog]

I bought a 2018 Colorado Diesel Z71 4x4 in 2020 (35,000 miles then) and absolutely love this truck, however, I just started experiencing this problem. My engine has died when pulling away from a stop sign twice now about two weeks apart. It throws a P1682 code, but found the F09 fuse blown both times and have replaced fuse and truck runs great.

Any idea why this fuse now all of a sudden keeps blowing? Any help would be appreciated. Seems my local and not so local Chevy dealers do not have diesel mechanics....

 

[White016]

I bought a 2018 Colorado Diesel Z71 4x4 in 2020 (35,000 miles then) and absolutely love this truck, however, I just started experiencing this problem. My engine has died when pulling away from a stop sign twice now about two weeks apart. It throws a P1682 code, but found the F09 fuse blown both times and have replaced fuse and truck runs great.

Any idea why this fuse now all of a sudden keeps blowing? Any help would be appreciated. Seems my local and not so local Chevy dealers do not have diesel mechanics....

I think I would do the wiggle wire test. Best guess I think is an intermittent short to ground.
I remember reading about a short on diesels being common, maybe even a TSB on it? But I don't think it was fuel injector related. I tried to search for it and didn't find it.
This was it I think. pinched wiring harness.

Electrical Gremlins...

Hey All, this is a long sucker but bare with me... just wanted to tell a story and see if anyone else can relate... My 2018 Colorado Z71 Diesel seems to have some electrical issues. Here's the low-down so far: About a month ago, I'm pulling into a parking spot, most of which are made for...

www.coloradofans.com

 

[DieselDrax]

I think I would do the wiggle wire test. Best guess I think is an intermittent short to ground.
I remember reading about a short on diesels being common, maybe even a TSB on it? But I don't think it was fuel injector related. I tried to search for it and didn't find it.
This was it I think. pinched wiring harness.

Electrical Gremlins...

Hey All, this is a long sucker but bare with me... just wanted to tell a story and see if anyone else can relate... My 2018 Colorado Z71 Diesel seems to have some electrical issues. Here's the low-down so far: About a month ago, I'm pulling into a parking spot, most of which are made for...

www.coloradofans.com

The TSB doesn't mention P1682, unfortunately.

 

[16WhiteColly]

Chafed wire harness somewhere, a good chance.

 

[Duken4evr]

First place to look at the wire harness is behind the driver's side front wheel, there is an A/C line there with a bulge in it and the portion of the harness that runs by there likes to chafe. Mine wasn't chafed through, but it was rubbing there. I wrapped it in an overkill amount of thick rubber and quality zip ties. Even if you don't have a problem there, it is a worthwhile preemptive fix. Access is a lot easier if you remove the fender liner, which just takes a few minutes.

On a side note, if one parks their truck in a place where they are worried about it getting ripped off, pulling the fuse we are talking about here is a great form of theft prevention. Years ago I used to pull the rotor out of the distributor cap on my '79 Dodge pickup if I left it in a place where theft might be an issue. The distributor cap had spring clips, so it was a toolless job to pull the rotor. Parked it in the airport parking garage for a week, came back to a jimmied door, blown out ignition and dead battery. Popped the rotor back in, pushed it out of the parking space, rolled down the ramp, dropped it into 2nd gear, bump started it and drove home. Gotta love simple vehicles with a stick That well cared for 225 Slant 6 had 150K miles on it when I sold it, ran like new. Never had a problem with that truck as there literally was not much to go wrong with it, being basically a simple engine and a chassis bare bones kind of situation. I wonder how long that truck went...

 

[PatrioticSheepdog]

I like the anti theft thoughts. That would be perfect and easy to do without tools.
It happened again today, this time driving 45mph during rush hour. Thankfully a deputy happened upon me and gave me cover as I was on a curve. Tried the fuse swap 4 times, each time it let me get a bit closer to moving...first time it blew immediately, second it started and when I put into drive it blew, third time it allowed me to get into drive and it blew as soon as I released the brake, and the fourth time it allowed me to give it fuel but soon blew so I went 10'....had it towed home. Put 10a in and it is running again. I will search again for a chaffed wire...I really do not want to leave the 10a fuse in where a 7.5a is called for...