# DEF consumption Rate



## Coop73 (Feb 28, 2020)

2014 CTD.
Currently using full version of Torque and Biscan w/OBD Link Bluetooth adapter.
I've been seeing & clearing CELs with P20 & P21 codes pretty regularly.
My DEF level shows 100% and it dips when braking (sloshing around I assume). The car has performed 6 regular regens since I've started monitoring with Biscan. The last regen was soon after soot % reached 21ppm.
My DEF level remains unchanged after 6 regens. The DEF Quality death count down started a few miles after.
Any suggestions? I'm thinking that the DEF delivery isn't happening either a clogged line or failed pump. Searching test procedures now. 

Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## Coop73 (Feb 28, 2020)

Removed the injector assembly without a problem. A few drops of DEF dripped out of the supply hose but nothing more. 

The injector looks ok- no deposits, crystal or otherwise. Rinsed it in hot water anyway. The coil ohmed good and I could hear a click when I applied power to it at the bench. When I energized the imjectorI tried blowing through it via an attached tube~no dice.
So it's either:
1. Clogged
2. Has a very fine orifice
3. Mechanically jammed.

TBC..
















Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## Snipesy (Dec 7, 2015)

DEF is purged at some point when you shut off the vehicle. But it's likely you'll still get some drips as you saw.

NOx sensor 2 is the #1 cause for DEF Quality Errors. The second being a bad DEF Heater (sump unit). Third would maybe be an Injector or line issue in which case cleaning and flushing almost always fixes it. Fourth would be an actual DEF Quality issue wherein the DEF is contaminated. Funny how the DEF Quality actually being poor is the last on this list. A very distant issue is NOx Sensor 1 but since this is upstream of the DEF Injector it doesn't have the corrosion problems.

The DEF Quality Test is the best way to clear these errors. Unfortunately it doesn't work with BiScan but since you have an OBDLINK you can just use Gretio which comes with BiScan. See here: Poor DEF Quality . Given your symptoms although its possible the quality check may clear the countdown I doubt it will be a permanent fix. These tests are kind of a fuel hog so keep that in mind.

100% I would start with NOx Sensor 2.


----------



## Coop73 (Feb 28, 2020)

Thanks~
I've just put it together and was preparing to give it a test run. I've got Gretio but haven't spent any time setting it up. I watched your sick tutorial video this morning and I'm going to give it a try.
I replaced NOx2 in late December after the dealership diagnosed it as the cause of my previous death countdown. Diagnosis was "internally shorted". A trip back to the dealer was required and I paid 140.00 for a forced regen and a car wash.


Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## Snipesy (Dec 7, 2015)

Coop73 said:


> Thanks~
> I've just put it together and was preparing to give it a test run. I've got Gretio but haven't spent any time setting it up. I watched your sick tutorial video this morning and I'm going to give it a try.
> I replaced NOx2 in late December after the dealership diagnosed it as the cause of my previous death countdown. Diagnosis was "internally shorted". A trip back to the dealer was required and I paid 140.00 for a forced regen and a car wash.
> 
> ...


You can also bypass the heater itself with a resistor. You can consider this if you live in warmer areas.









uxcell 100W 4 Ohm Screw Tap Mounted Aluminum Housed Wirewound Resistors 2 Pcs: Single Resistors: Amazon.com: Industrial & Scientific


uxcell 100W 4 Ohm Screw Tap Mounted Aluminum Housed Wirewound Resistors 2 Pcs: Single Resistors: Amazon.com: Industrial & Scientific



www.amazon.com





I sadly do not know the wiring enough on the Cruze but 4 ohm should be enough to mimic the heater while also allowing the heater to still function without pulling too much power.


----------



## Snipesy (Dec 7, 2015)

Did some math. Resistance of DEF heater must be between 1.61 and 3.70 ohms according to the P21DD and P214F specifications.


----------



## Coop73 (Feb 28, 2020)

Thanks-
Ill have to check the heater next. I don't see any wrong temp wise, it's about 7 deg above outside air temp (51.8, vs 44)
Here's a test drive screen shot. It takes NOx2 several min to come up from 199 ppm/-6 02 but that seems normal.
The last Pic is post regen.























Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## Snipesy (Dec 7, 2015)

Coop73 said:


> Thanks-
> Ill have to check the heater next. I don't see any wrong temp wise, it's about 7 deg above outside air temp (51.8, vs 44)
> Here's a test drive screen shot. It takes NOx2 several min to come up from 199 ppm/-6 02 but that seems normal.
> The last Pic is post regen.
> ...


How many miles you got on this bad boy?


----------



## Coop73 (Feb 28, 2020)

126565-
I drive 150 to 300 miles per week mostly highway miles.









Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## Snipesy (Dec 7, 2015)

You should be seeing NOx 2 at about 30% of NOx 1. So like 150 in these pictures. This is true for normal driving at Operating Temps and when running a fluid quality test. But not necessary at idle.

During a regen NOx 2 will be higher as there is just more NOx and some stuff is getting burned even after NOx 1. This probably explains pic #2,

When coasting (DFCO) both sensors should read close to 0 ppm.

Excess NOx2 when its not suppose to can be a few things...

Excess DEF. Either from too much DEF being injected OR the catalyst being bad.
Residual DEF on the sensor. This can happen in colder temps.
Sensor malfunction
Bad fluid
A higher NOx1 when its not suppose to be can only be explained by the sensor being faulty.

These are also general rules. There may be times where a sensor spikes which is usually a temporary fluke and should not be considered.


----------



## Coop73 (Feb 28, 2020)

Snipesy-
Would you post a link to your Gretio tutorial? I didn't book mark it and I can't ssem to connect

Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## Snipesy (Dec 7, 2015)

Coop73 said:


> Snipesy-
> Would you post a link to your Gretio tutorial? I didn't book mark it and I can't ssem to connect
> 
> Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## Coop73 (Feb 28, 2020)

Thanks~
The instructions are simple enough. Gretio sees and recognizes the device but only connected for a few min.
Does torque need to be disabled?


Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## Snipesy (Dec 7, 2015)

Coop73 said:


> Thanks~
> The instructions are simple enough. Gretio sees and recognizes the device but only connected for a few min.
> Does torque need to be disabled?
> 
> ...


Torque can mess with things. Having them both open at the same time causes weird issues. If you go into your Settings -> Applications or Apps -> Find Torque -> Force Stop. That will insure it won't cause any more troubles.

But just having Torque installed shouldn't cause any problems.


----------



## Coop73 (Feb 28, 2020)

Yesterday I did a forced regen really out of desperation. No change to the DEF quality fault/death countdown as I expected. For me to get Gretio to connect I
disabled Bluetooth to the car and force stopped Torque. In Gretio I performed the DEF quality test, saw no change in fault status and quit for the day.
I headed off to work this morning with the 65 MPH limitation and 70 miles to go until 55 MPH. About 15 miles into the drive the DEF Quality fault & death countdown cleared.
When I got to work and stopped I had P21DD as a historic fault but no CEL.

So ~ the only thing worse than a fault I can't clear is an intermittent fault that clears itself.

I'm looking hard at DEF delivery~ pump, supply line and injector as well as verifying the vent is clear.
~The DEF heater keeps throwing a code.
~The DEF level shown on Torque has remained at 100% after 8 regen including 1 Service regen.

More to follow... 

Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## Burnzy (Dec 17, 2019)

Delete it. Problems solved.


----------



## Coop73 (Feb 28, 2020)

Thanks for the advice, but delete isn't an option I'll consider at this point.

I had updates due on my phone and several apps including Greitio. After the update and force stopped Torque, I was able to connect and remain no problem. I ran both DEF heater tests & they passed.
My battery is the original and while it cranks and starts it ain't what it used to be. At idle it's below 12.5V. I'm wondering if the lower voltage is causing an issue. Test and results to follow.. 

Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## MP81 (Jul 20, 2015)

That thing should be at 13.5V or above at idle, so it definitely sounds like it may be time for a new battery.


----------



## boraz (Aug 29, 2013)

Coop73 said:


> Thanks for the advice, but delete isn't an option I'll consider at this point.
> 
> I had updates due on my phone and several apps including Greitio. After the update and force stopped Torque, I was able to connect and remain no problem. I ran both DEF heater tests & they passed.
> My battery is the original and while it cranks and starts it ain't what it used to be. At idle it's below 12.5V. I'm wondering if the lower voltage is causing an issue. Test and results to follow..
> ...


are you reading battery voltage or alternator voltage?


----------



## Coop73 (Feb 28, 2020)

I noticed the lower voltage at idle but I checked this morning before I started and it was 12.25. Definitely on the low end. I really took a chance this winter, fortunately it was a mild one. 

Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## MP81 (Jul 20, 2015)

Yup, I'd say your original battery is probably ready to be replaced. Welcome to the club! At least yours didn't drop a cell out of nowhere, on your drive into work...on a 50 mph road...in the fog, haha.


----------



## e-iowa-o (Sep 2, 2015)

Coop73 said:


> Thanks for the advice, but delete isn't an option I'll consider at this point.
> 
> I had updates due on my phone and several apps including Greitio. After the update and force stopped Torque, I was able to connect and remain no problem. I ran both DEF heater tests & they passed.
> My battery is the original and while it cranks and starts it ain't what it used to be. At idle it's below 12.5V. I'm wondering if the lower voltage is causing an issue. Test and results to follow..
> ...


I started with the countdown down to 35 miles till 4 MPH so it was just parked in the garage. 

I too had a great deal of difficulty trying to operate with ODBlink MX and Gretio running at the same time. 

What threw me off was that when I started I had only used a generic Bluetooth adapter and regular Torque. I've used that exclusively for years. Biscan was suggested and when I loaded the app from Play Store (android) I had Torque open and clicked to add it on and it went in seamlessly. 

With Biscan I determined, as best I could figure, Nox 2 was bad. It was suggested that I get Gretio and that I might be further able to diagnose what was wrong but that OBDLink would be a better interface. 

I ordered the new code reader and Nox 2 sensor, eventually swapped the sensor out, and then downloaded Gretio. I'd read that Gretio would act funny if Torque was running so I didn't open that but I didn't realize that Gretio and OBDLink would not intersect like Biscan did with Torque. Having that expectation I spent a few hours trying to run them both together and could never get them both to remain open. One or the other would disconnect. Eventually I got frustrated and uninstalled Torque and Biscan (I don't know if I'll need to rebuy that) and got any other obd readers out of my Bluetooth list. OBDLink app and Gretio ran separately for me but the OBDLink code reader is the interface to connect to the car.

I went back to another tread where Snipsey remarked that, if there weren't any other problems, that the DEF quality test on Gretio would clear the warning. Said have it outside with hood open and be prepared for it to run quite a while. I don't remember exactly , I think he said as long as 90 minutes.

Mine ran for about 20 minutes and when the RPMs came down the warning was cleared. The countdown is gone (for now) and I am back on the road. If his didn't work I was firmly committed to not take it to the dealers service department again. I was definitely going Burnzy's route and I probably still will eventually.


----------



## BDCCruze (Jul 12, 2017)

Just to chime in here, I think the DEF tank always reads 100% until it hits 36%, then it starts showing the level. I remember a few years back I tried reading my tank level and it always showed 100% but randomly dropped down then back up. I suspect the reason they do that is because of how long it last and the random check is just to check the level, and it probably stays at 100% so that the DIC warning doesn't come up until it's actually getting close.

My DEF usage is probably 20k miles per 5 gallons. It's very minimal.


----------



## Coop73 (Feb 28, 2020)

Thanks for the DEF level info~ I've been watching my for about 2K miles and it's 100% except when I'm making a turn and it dips to 66 or 33%. 

Sent from my SAMSUNG-SM-G930A using Tapatalk


----------



## boraz (Aug 29, 2013)

BDCCruze said:


> Just to chime in here, I think the DEF tank always reads 100% until it hits 36%, then it starts showing the level. I remember a few years back I tried reading my tank level and it always showed 100% but randomly dropped down then back up. I suspect the reason they do that is because of how long it last and the random check is just to check the level, and it probably stays at 100% so that the DIC warning doesn't come up until it's actually getting close.
> 
> My DEF usage is probably 20k miles per 5 gallons. It's very minimal.


eggsactly

99% of the time the def level on DIC read OK between oil changes, was rare to get an actual countdown unless i really made an effort to run the def tank down...usually topped it up erry oil change


----------



## BDCCruze (Jul 12, 2017)

Snipesy said:


> Did some math. Resistance of DEF heater must be between 1.61 and 3.70 ohms according to the P21DD and P214F specifications.


I got the p21dd again, after having it replaced 2 years ago. I believe I'm on the right connector, it's 9 ohms. Time to replace?

Looking at these wiring harness connectors, they appear to be snapped down on the plastic cover somehow. Not sure how to remove them.

_edit_ Ok they just slide off.

Neat video showing replacement of tank


----------



## LiveTrash (May 24, 2015)

BDCCruze said:


> I got the p21dd again, after having it replaced 2 years ago. I believe I'm on the right connector, it's 9 ohms. Time to replace?
> 
> Looking at these wiring harness connectors, they appear to be snapped down on the plastic cover somehow. Not sure how to remove them.
> 
> ...


Did you replacing it yourself? What is your mileage at? There's extended coverage for the reservoir replacement.


----------



## BDCCruze (Jul 12, 2017)

LiveTrash said:


> Did you replacing it yourself? What is your mileage at? There's extended coverage for the reservoir replacement.


Yes, I replaced it myself. I'm at 135,000 or so, I'm out of the special coverage. This is now the second time I've had to replace the heater, the first time was under warranty.

And to followup my first post about the resistance, I checked the new heater and it was at 3 Ohms vs 9 Ohms on the failed unit.

Also, I found a bunch of glitter (larger kind) in my DEF fluid tank sitting on the bottom. I remember the last bottle of DEF I bought at Wal Mart didn't have a seal on the bottle. I wonder if someone contaminated it... Either way I had to use a turkey baster to suck out all the pieces.


----------



## Coop73 (Feb 28, 2020)

So to update this old thread, I did replace the battery (voltage readings at the battery terminals). That didn't change anything with the reoccurring 21DD code.
I bit the bullet and replaced the heater, 2nd for this car, 1st was under warranty. That cleared the historic faults and restored everything back to normal. 
Examining the heater I now understand the DEF level sensor, essentially 100, 60, 30% and low.
Thanks to all for advice and help, especially Snipsey with Torque/Gretio.
Cheers ~


----------

