does DEF freeze on you?!?

[great white]

First off, I don't have a new DMax.

But I have been reading a bit here and there.

I've read a couple places that def freezes between -9 and -11 C.

WTF?

Does it freeze up on you in the tank and lines in cold weather?

This can't be true, otherwise no one north of Florida would be able to run one....there must be a heater or something.....

Even if there is a heater, wouldn't it be frozen up when you leave it overnight?

Very curious on how GM dealt with this....

 

[THEFERMANATOR]

Yes it freezes, and yes they have a heater. Problem is though when the DEF freezes the engine will run in reduced power mode of about 40-50% power until the def comes back up to a liquid state.

 

[bigdisneydaddy]

I think they already had a service bulletin about it in very cold climates. Places like Alaska and Canada had cold enough weather that the stock heater was insufficient.

 

[great white]

Well, I can cross any DEF equipped truck off my future "must buy" list.

What the heck were they thinking?

You need it to run as per normal but it can freeze overnight.....I mean, really.

What were they thinking?

 

[BoostN]

They are putting insulated tanks in the Severe northern climates for the freezing issue. Since the latest reflash update, not many problems are being reported with the DEF now.

 

[great white]

They are putting insulated tanks in the Severe northern climates for the freezing issue. Since the latest reflash update, not many problems are being reported with the DEF now.

But, what happens if your truck sits for a couple days in -15 C temps?

Not an unusual circumstance around these parts.

Or even just overnight?

Frozen DEF?

Dead battery so no start?

Plugging in a heater is not an option at an airport parking lot and such.

Sounds like a PITA all the way around to me....

 

[BoostN]

But, what happens if your truck sits for a couple days in -15 C temps?

Not an unusual circumstance around these parts.

Or even just overnight?

Frozen DEF?

Dead battery so no start?

Plugging in a heater is not an option at an airport parking lot and such.

Sounds like a PITA all the way around to me....

The heater doesn't run unless the truck is running. I'm not sure how GM designed it, but.. I'm betting they have a waiting period programmed for the DEF while the tank is frozen.. Could you imagine the pissed off people that starts their truck every morning and you have to wait for your tank to unfreeze, that's not logical, and GM's phones would be ringing off the hook and the forums blowing up.

I'm not saying it's the greatest thing either, but mine hasn't give me one problem (DEF related). Granted my parts aren't as cold as most.

 

[LtEng5]

there is a heater hose line type set up for the DEF tanks. as the engine warms up and you get heat in the cab; the DEF tank also is heated. As I understand it there is no reduced power with a frozen DEF system. I could be wrong here thou.

 

[JiFaire]

This is a GREAT question, guys... one of those things that some engineer (in a warm climate) just wouldn't think of...

... and one that every guy in Alberta or Alaska can't ignore!

 

[btfarm]

It seems to me that since all kinds of DEF equipped vehicles have been running for years in Europe that there wouldn't be all that much for them to have figured out. A bunch of operational data should already be available. Add in that all the major OEMs do at least a couple of years of testing in extreme climates for most every all new system. Should be a slam dunk. Or at least only minor issues.

 

[BoostN]

I know it gets cold in Detroit.. that is the heart of these trucks ya know... Freezing is freezing.

 

[ryanryan]

But, what happens if your truck sits for a couple days in -15 C temps?

Not an unusual circumstance around these parts.

Or even just overnight?

Frozen DEF?

Dead battery so no start?

Plugging in a heater is not an option at an airport parking lot and such.

Sounds like a PITA all the way around to me....

WOW.........do you honestly think GM would release a truck with that much bullshit going on??? Other than the one DEF problem I had(which wasn't related to cold weather), first year truck....NBD, I haven't even noticed that there is a SCR system on it. I've never had any problems, and my truck has sat outside for a week or more at -20*C. There is no reduced power mode or any other stuff like that, you just start it up and go....it'll thaw itself. I've never plugged my truck in, BTW.

AND.....many class 8 trucks have been running SCR systems for years and years. It's nothing new...... This type of post comes up every winter!!

 

[3500GMC]

Bottom line: The EPA is slicing our throats.

They legislate the impractical with lofty goals and zero tolerance effective- NOW.

Meanwhile china spews forth filth into the sky, everyday, far exceeding the U.S. now, and in it's manufacturing height/hay-day way back.

 

[JiFaire]

Ok, so we have 3 votes for 'it's gonna be fine', which is usually my line, since I'm the big SCR supporter, but I'm still curious; what happens to your power once the stuff freezes?

Class 8 rigs don't have an automatic 'power-reducer' on them when your DEF system is not working (frozen or otherwise) like the new trucks.

Before anybody gets uptight about the sky falling or not, re-read post #2.

If DEF freezes (which it should, chemically), I will assume that the engineers have taken care of any expansion issues (which are a water-based phenomenon), but if the engine will really run in reduced-power mode until the DEF thaws out, I would honestly like to know that.

I know Ontario and Detroit get chilly, but we really do see -40 several times a year, and it would be nice to know if you can add an antigel to the stuff?

 

[great white]

From Gm techlink:

When filling the Diesel Exhaust Fluid (DEF) on the 6.6L Duramax diesel engine available on the 2011 Silverado and Sierra HD trucks and 2010 interim and 2011 Express and Savana vans, it's important to not overfill the DEF tank.

TIP: With colder weather coming, keep in mind that DEF behaves like water and will freeze at 12°F (-11°C) and will expand.

Adding more than the 5.3 gallon (20 liter) usable capacity may not allow for DEF expansion if it freezes.

DEF will not be damaged by freezing, and will remain fully usable when thawed. The fluid tank includes a DEF pump heater, reservoir heater and line heater.

Vehicles are shipped with 2 gallons (7.5 liters) of DEF from the assembly plant. To prevent damage from freezing, at customer delivery or during PDI, do not add more than approximately 3.3 gallons (12.5 liters) of remaining capacity.

The 5.3 gallon (20 liter) capacity of the DEF tank will last approximately 5,000 miles (8,000 km) depending on drive cycles and vehicle use. The easiest way for customers to ensure that the tank is not overfilled is to wait until the EXHAUST FLUID RANGE: 1000 MILES (1600 km) message is displayed on the Driver Information Center. At this approximate mileage, add no more than 3.5 gallons (13 liters) of DEF. When fluid reaches the top of the fill pipe, stop filling.

On the 2010-2011 Express and Savana and 2011 Silverado and Sierra equipped with the 6.6L Duramax Diesel engine (RPO LML, LGH), the Diesel Exhaust Fluid (DEF) may freeze if the vehicle is operated in low ambient temperatures (16°F, -9°C or below) for extended periods of time.


As a result, the vehicle may be speed limited and the following Driver Information Center (DIC) messages may be displayed: Exhaust Fluid Low, Exhaust Fluid Empty - Refill Now, or Exhaust Fluid Range: XXX (range shown depends on message level). These conditions may be present even if the ambient temperatures are not currently less than 20°F (X°C), but were previously.


TIP: All engine DTCs must be repaired before the DEF messages are addressed, including DTCs concerning poor quality DEF and servicing the DEF system.


For low DEF messages and speed limiting on a vehicle known to have a full tank of DEF, an updated calibration is available in TIS2Web. Refer to #PIP4864D for additional information.


DEF Level


The DEF system includes three reductant (DEF) heaters, which are located in the reductant reservoir, the supply line to the reductant injector, and at the reductant pump. The ECM monitors the reductant temperature sensor in the reservoir in order to determine if reductant temperature is below its freeze point. If the ECM determines that the reductant may be frozen, it signals the Glow Plug Control Module (GPCM) to energize the reductant heaters. DEF will not be damaged by freezing, and will remain fully usable when thawed.


When the DEF is frozen, the DEF level may not be recognized until the fluid around the Discrete Level Sensors (DLS) has thawed.


To verify if the fluid is frozen, use the Tech 2 DEF level reading function. After a normal DEF tank fill, the DEF level reading on the Tech 2 should increase to 100%. If fluid was added and the level does not change, the fluid may be frozen. The fluid will have to be thawed before completing any repairs. A reading of 100% does not indicate that the entire tank is thawed. As the fluid in the tank is thawing, it is normal to see the level sensors in the tank react differently than when the fluid is thawed.


If the fluid is determined to be frozen, the truck may be in "Frozen Tank Status," in which the level sensors cannot determine the fluid level in the tank and the ECM assumes a default fluid level and bases remaining range on DEF dosing history. This may result in a Fluid Low or Fluid Empty message being displayed.


The updated calibration in #PIP4864D will allow the ECM to check the level of DEF when a range of less than 1,000 miles (1,609 km) occurs; previously, DEF level was checked when the ranged dropped below 300 miles (483 km). Also, the DEF level will be checked when the temperature has warmed enough to have thawed the fluid. These conditions will be intermittent based on ambient temperature changes.


Programming


It is critical to follow the information as outlined in #PIP4864D. Here are some of the highlights.


Before programming to address the DEF messages, drain the DEF tank. Verify the tank is completely empty by using the Tech 2 to check that all three Reductant Level Sensors are inactive.


The ECM is reprogrammed using a two-part level reset calibration. Part one of the calibration is titled: ECM DEF tank fluid level warning latched reset programming per PIP4864.


After programming part one of the calibration, fill the DEF tank with a maximum of 5 gallons (18.9 L). Do not add DEF while the ignition is ON or while the vehicle is running. Use the Tech 2 to verify that the Reductant Level Remaining Distance has reset to more than 4,000 miles (6,430 km). This verifies that the calibration was installed correctly.


Part two of the calibration is titled: Engine Control Module. If this calibration is not programmed, the vehicle will be limited to 5 mph (9 km/h).


TIP: Refer for # PIP4864D for complete details about the programming procedures. Every step must be performed as detailed in order to properly complete the repair.


Do not replace the DEF tank or other DEF system components for this condition unless Service Information diagnostics indicate the need.

DEF in Cold Weather

DEF is a colorless, clear solution of water and nitrogen-based urea product that has 32.5% urea by weight. DEF will freeze at temperatures below -11° C (12° F). The fluid will not be damaged by freezing, and will remain fully usable when thawed.

The DEF tank assembly contains the DEF pump, pump heater, reservoir heater, line heater, level sensor and temperature sensor.

Several updates have been made to the DEF system for the 2012 model year. The pin heights in the level sensor have been updated to support new requirements. 2011 model year and 2012 model year tanks cannot be interchanged. Additionally, there is a new shield along with insulation around the DEF tank. (Fig. 2)

F02_Dec_2011_Techlink.jpg

Fig. 2

Also new for 2012 is the supply module insulation and a stainless steel heater spacer that has been added to the reservoir assembly. (Fig. 3)

F03_Dec_2011_techlink.jpg

Fig. 3

2012 Warning Messages

The Driver Information Center (DIC) warning messages and vehicle speed-limited inducement are designed to notify and encourage customers to have their vehicle serviced for conditions that may result in higher tailpipe emissions.

The distance remaining value for the DEF level is calculated from DEF tank mass and average consumption rate. For 2012 models, the DIC messages are the same as 2011 models until the distance remaining is 75 miles.

The transition into vehicle speed limitations is now based on the displayed countdown mileage and entry into and exit from speed limitations occur while driving. In 2011 models, the speed limitation only occurs when the vehicle is stationary and exit occrs only when vehicle speed is less than 1 mph (1 km/h).

For 2012, there a three speed limitations instead of two: 65 mph (105 km/h), 55 mph (88 km/h), and 4 mph (6 km/h) with updated speed limitations and DIC warning messages.



Action


DIC message

0 mileage range


400 miles until 65 mph max speed

Mileage counter expires


Transition to 65 mph max speed

After ramp down is complete

75 miles until 55 mph max speed

Mileage counter expires

Transition to 55 mph max speed

After ramp down is complete; allows 3 events per key cycle

75 miles until 4 mph max speed

Mileage counter expires

Transition to 4 mph max speed

After ramp down is complete; unlimited events per key cycle

Speed limited to 4 mph

DEF System Conditions

TIP: 2012 model year vehicles have all the updates for the following conditions.

11001A: Product Emission - Diesel Exhaust Fluid Calibration Enhancement has been released to address the Exhaust Fluid Empty and Exhaust Fluid Range Message Will Not Reset condition. If the vehicle has a latched DIC message prior to installing the updated calibration, follow the reset procedure covered in #PIP4864K.

DTC P204F (Reductant System Performance) is set when there is a failure to build system pressure, maintain system pressure or there is an over-pressure condition. Failure to build system pressure is linked with the tamper mode, which will eventually limit the speed of the vehicle if the condition is not corrected.

DTC P204F may set when operating in extremely cold temperatures where the DEF may freeze in a vehicle that has not had the 11001A: Product Emission - Diesel Exhaust Fluid Calibration Enhancement completed, is using an aftermarket winter cover, or is using a winter cover and a snow plow. A Service Exhaust Fluid System message may be displayed on the DIC. The latest versions of #PIP4864K and #PIP4866A may help explain or address these conditions; otherwise, follow the appropriate Service Information diagnostics.

When DEF is frozen, the Discrete Level Sensors (DLS) cannot detect that DEF is present. This will cause the vehicle to go into a frozen tank status at temperatures less than -9° C (15° F)

Entry into frozen tank status is based on tank temperature evaluation. (Additional information is available in Bulletin #10-06-04-013A).

The condition is corrected by thawing the DEF tank during normal operation or by adding liquid DEF. There are three methods to exit frozen tank status.

· Engine off for four hours with a DEF tank temperature greater than -8° C.

· The following conditions are met for a total integrated time of at least four hours: DEF tank temperature greater than -8° C, ambient temperature is greater than -7° C, and vehicle speed is greater than 10 km/h (6 mph).

· Use the Tech 2 scan tool to reset the reductant fluid tank level. DEF tank temperature must be greater than -9° C.

There ya go. Decide for yourselves if it is a problem or not.

 

[Ed HD]

I was at a Farm Bureau conference last January in Duluth MN, and at lunch one of the days the guy was on and off the phone with the local dealer, as his DEF was frozen and the truck was in limp-home mode, not allowing him to go over 50 MPH (pretty much all 4-lane freeway for 400 miles for him home too) and the dealer couldn't do anything, since the truck was so new, they had no idea. It may have broken something too, but he was pretty much SOL and had to drive home at 50 from what I heard...

 

[3500GMC]

^^ The guy was probably thinking "I can't drive my 50 thousand dollar f'n truck because my f'n piss tank is frozen" ^^

 

[BoostN]

I was at a Farm Bureau conference last January in Duluth MN, and at lunch one of the days the guy was on and off the phone with the local dealer, as his DEF was frozen and the truck was in limp-home mode, not allowing him to go over 50 MPH (pretty much all 4-lane freeway for 400 miles for him home too) and the dealer couldn't do anything, since the truck was so new, they had no idea. It may have broken something too, but he was pretty much SOL and had to drive home at 50 from what I heard...

I don't know what you would break. The computer limits the power because it isn't sending fluid through the lines. That's why it's limited...

The DEF system is without a doubt something else to cause trouble and break.. But, we better get use to these things as I don't see it ever becoming any better (emissions wise) until something else comes out to replace this DEF.

 

[Ed HD]

I'll just buy up a fleet of 05-07's. IMHO they look better and no emissions crap.

 

[ryanryan]

Ok, so we have 3 votes for 'it's gonna be fine', which is usually my line, since I'm the big SCR supporter, but I'm still curious; what happens to your power once the stuff freezes?

Class 8 rigs don't have an automatic 'power-reducer' on them when your DEF system is not working (frozen or otherwise) like the new trucks.

Before anybody gets uptight about the sky falling or not, re-read post #2.

Re-read post #12....

There is no mode that it goes in to, once the tank is frozen. It assumes a level, and let's you go and warm up. It could go into limp mode, but part of the recall addressed that. In some cases(not many), their truck would go into limp mode and say low DEF or DEF quality low if the DEF froze. That is now fixed, the heating cycle is improved, and they added a shield and insulation for Canadian residents.