P2146 LML 2016 GMC Dually

[BandJCarm]

2016 GMC LML Diesel, Denali Dually.

Pulled into campground Clearwater, MN for 3 days, heading west next few weeks. Dropped camper, went to town to eat. Stopped in front of restaurant to turn left and truck is shaking. Idling VERY rough. Scangauge II connected, so I checked codes, and got P2146. Looked it up, something about voltage to injectors.

Limped back to camper, here now. Called local Chevy (Monticello, MN Cornerstone Chevy) and left message. Guy called me back!!! Sat night, wow. Listened to story, said he'd TRY and get me in Monday morning. I said I'd be there if I could limp in. He asked if DIC had Check Engine Light. I said No, but after hanging up I went back out to re-check what DIC looked like.

TRUCK STARTED FINE, IDLED SMOOTHLY, RAN GREAT, NO CODES ON SCANGAUGE.

???????????????????????

I will still try and get to dealer service by Monday anyway, but this is bizarre.

I am no gearhead. I can pump fuel and run the radio.

Anyone have a clue?????????????

[aceinspp]

lets hope its not related to DEF. Later RJD

[spock123]

My Silverado did something similar on my Alaska trip. Light came on that said poor quality def fluid, light finally went off after a hundred miles and scaring me and DW half the death. When I stopped at the campground the light went off. I checked with my code reader and no code was showing. Took truck to Chevrolet dealer in Fairbanks, they could not find a code. Since no code was thrown the dealer couldn’t fix anything. Said drive it.

[BandJCarm]

I have NO clue why you guys think this is DEF related. Every thing that happens to a Chevy is not DEF related. Geez Louise. Some of you think DEF is the devil. It's easy to add, does its job, doesn't hurt anything, and doesn't cause me any problems. Removing it doesn't help any, either.

No, this is electrical as it relates to the wiring to the injectors. It fixed itself, so I assume it's a simple wiring short. I'm no mechanic but I would bet this is an easy fix. Here is from the Duramax Forum:

Check the ECM harness for wear-- possible shorting against metal-

That code was cvommon for trucks with a FICM [01-05] whenn there was a bad connection at the injector- then it would shut down all injectors in that group and set a P2146- for one group, or a P2149 for the other group. Rare code for a 2016 truck

[Bobaloo]

My friend had the same type of issue and it was that his batteries were weak. He replaced them and all is good. Hope yours is this simple.
Bob

[BandJCarm]

I thought I fixed it but it is back again. I can only hope that a weak battery is the issue! I will have to limp to dealer in the morning.......20 miles down I-94 with inflow Minneapolis rush hour traffic.

[BandJCarm]

Just got back from dealer. It's a bad Fuel ECM wiring harness. Electrical issue. Injectors are ok. Battery is ok. Ordered new part, it should (?) be here tomorrow.

Sorry it's not DEF related. I know that disappoints you DEF-haters! LOL

We're stuck here in campground till it's fixed. If storms don't blow us away tonight, could be on our way tomorrow, or next day.

[BandJCarm]

And...........I'm on the way. New ECM Wiring Harness installed, all works fine, back on America's Fine Interstate system tomorrow! All under warranty, no charge.

[DreiHunde]

Originally Posted by BandJCarm

And...........I'm on the way. New ECM Wiring Harness installed, all works fine, back on America's Fine Interstate system tomorrow! All under warranty, no charge.

What? No DEF issue? That cant be right!

Seriously though glad they got you back on the road with minimal delay!

[spock123]

Originally Posted by BandJCarm

And...........I'm on the way. New ECM Wiring Harness installed, all works fine, back on America's Fine Interstate system tomorrow! All under warranty, no charge.

I like that under warranty. I don’t have that anymore of course I have no emissions stuff to worry about.

[Bobaloo]

YAY!!!

[spock123]

I just saw a 2019 GMC Denali 3500 Dually, wow was that a pretty truck. $74,000.00