Chevy Colorado Diesel Forum banner

1 - 16 of 16 Posts

·
Registered
Joined
·
1,384 Posts
Discussion Starter #1
Got my first check engine light last night. Cleared the code and it didn't come back on, I'll keep y'all updated.

The DIC said service exhaust fluid system 99 miles until speed reduced to 65mph. I got a check engine light and a def light.

My efilive auto cal told me there were no DTCs but it did let me clear the code. All seems well for now.

If it comes back I may get it repaired under warranty and/or delete.

Hopefully it was a fluke, I've had a few weird things like "service rear camera" pop up for just a second even though it's all working
 

·
Registered
Joined
·
1,384 Posts
Discussion Starter #4
Maybe you guys more familiar with diesels can help me. See above for the check engine light.

Looking through my PIDs at idle I see these. Does the truck have two nox sensors and I have a bad one? Did this cause my check engine light? I'm assuming nox2 would be downstream. Makes sense to me

Forgive my leg in the pic I was more worried about the truck

IMG_6354.JPG
IMG_6353.JPG
 

·
Registered
Joined
·
44 Posts
My big diesel has very little emission control equipment so this is new to me. The big trucks are not tested at the tailpipe here in Texas. This New truck will be subject to emission testing. We also had the VW Passat and I'm sure it has similar emission controls as our beloved little trucks. The VW was a great car. No emission code like that ever.
 

·
Registered
Joined
·
1,384 Posts
Discussion Starter #6
Diesels aren't required to pass smog in Georgia at all whether it's a Passat or a Cummins.

But I don't want check engine lights or reduced speed
 

·
Registered
Joined
·
7 Posts
I been lurking for a while, figured I'd post in this one.

I got a P24B1 about 12K miles in. It was a bad Particulate Matter sensor. Dealer was able to get part and replace pretty quickly. I don't know if this helps but it might help someone in the future.
 

·
Registered
Joined
·
1,384 Posts
Discussion Starter #8
I flashed back to stock tune just in case I need to run by the dealer and still saw nox2 reading 0.0 drove about 20 miles last night.

This morning my truck started a regen and my nox2 was reading normal, which is just a bit lower than nox1.

Can anybody with a spade or other device that can read diagnostics pull up your nox2 readings?

I'm trying to determine if nox2 only reports to the ecm when the truck is in regen, or if I have a ground problem or a bad sensor that is reporting haphazardly.

If others are seeing nox2 at 0.0 or 1.0 when the truck isn't regen-ing that would give me some peace of mind.
 

·
Registered
Joined
·
1,384 Posts
Discussion Starter #10
Helpful indeed. I had another sporadic issue and that prompted me to check my grounds. So, I have already checked my grounds, but it was raining and I only found a couple. I did find that ground near the driver rear tire that he speaks of, don't know what main ground he speaks of. But, i checked the battery and the grounds I saw. I'll check again if it ever stops raining.
 

·
Registered
Joined
·
1,384 Posts
Discussion Starter #11
Truck seems to be fine.

Maybe it got really pissed off becuase I let the def get low. Many people have told me that will piss off the ecm.

Also have been told the nox sensor doesn't work until a certain temperature so maybe nox2 takes longer to report.
 

·
Registered
Joined
·
92 Posts
DEF quality alarm can be triggered by the up and downstream NOX sensors seeing enough difference in NOX.
This can be due to number of things.
1) Actual poor DEF quality. You could drain bad refill DEF tank.
2) Not enough heat in combustion/exhaust due to cold ambient temps, low load or short trips which creates low NOX in exhaust and therefore not enough difference for the sensors to see.
3) DEF injection rate too low to allow SCR to reduce NOX thereby triggering low NOX differential code.
Not sure how your programmer will affect these parameters.

I have had 2 of these codes. The first time, dealer went through a series of checks to confirm DEF good, injector and rate good and reset the parameters in the ECM. Had another a few weeks later, also in the winter, low load situation, and Code cleared after 15 miles more driving.

Hope this helps.
 

·
Registered
Joined
·
60 Posts
Wow, a year later this gets 'sell it and buy something completely different'... meanwhile RCD is the most active member on the forum and seems to love his truck.... he's given me quality advice and his posts actually helped me decide to get one!
 
1 - 16 of 16 Posts
Top