service emissions message

[bd1028]

2015 Silverado ccsb duramax ltz z71
37000 miles
weather is 13 degress this morning when warming up truck message came on saying sevice emissions . 174 miles left until decrease to 65 mph . any thoughts on this ?
already call the dealership going in Monday .

[convert2diesel]

Frozen DEF fluid????

Bill

[trbankii]

^^ That would be my guess.


A 32.5% solution of DEF will begin to crystallize and freeze at 12 deg F (-11 deg C). At 32.5%, both the urea and water will freeze at the same rate, ensuring that as it thaws, the fluid does not become diluted, or over concentrated. The freezing and unthawing of DEF will not cause degradation of the product.

[rapidoxidationman]

For all of us DMax owners who are Pre-Urea: What does the truck do to keep the DEF from freezing?

Also, "unthawing" is freezing...;)

[DmaxMaverick]

For all of us DMax owners who are Pre-Urea: What does the truck do to keep the DEF from freezing?

Also, "unthawing" is freezing...;)

They have a pump/heat unit in the tank. Heater failure isn't uncommon. I know of several DEF heater failures in all classes, passenger car to HD truck. The heater in our 2014 Cruze Diesel failed at about 35K. The good news is, they are covered under warranty for a long time/miles, and aren't that expensive or difficult to repair if not.

[bd1028]

thanks for the response , does the engine block heater also cover the def tank when plugged in ?

[DmaxMaverick]

thanks for the response , does the engine block heater also cover the def tank when plugged in ?
No. They are in different locations. Only the DEF heater is ECM managed. The block heater is only an element on the end of an AC power cord. The DEF heater is effective (when it works), and shouldn't cause issues even if a deep-freeze occurs (-40 and below). I'm not likely to see this in CA (unless this global warming continues), but that's the description. The heater is able to thaw the contents of the tank, and the urea injection events can be postponed until fluid temp is sufficient. If this period is too long, or the heater circuit (voltage and resistance, relay and element) is not within specs, it will set a DTC and the DIC message. The diagnostic cycle is performed at every start, so any temporary condition will reset the message and the reduced power mode once the condition returns to normal.

[bd1028]

thanks for the reply . very much appreciated , I will post after Dealer visit and update .

[rapidoxidationman]

Interesting thread. Thanks DMax for your response and the light it sheds on how the system works. Are the lines from the DEF tank heated as well or is there something circulating from the truck's cooling system that thaws things out as necessary?

Looking forward to learning what the dealer finds and how it gets repaired. The more you know...

[DmaxMaverick]

Interesting thread. Thanks DMax for your response and the light it sheds on how the system works. Are the lines from the DEF tank heated as well or is there something circulating from the truck's cooling system that thaws things out as necessary?

Looking forward to learning what the dealer finds and how it gets repaired. The more you know...

In every application I've seen, including the Duramax, the systems are generally local, and all but heavy duty and off-highway (some do have heated lines), are nearly identical within their application class. The passenger cars (Cruze, VW, Mercedes, Audi) have all of the system shrouded and surrounded by or in contact with the cabin (such as the spare tire location in the trunk) and well insulated. The lines are not heated, but are shielded and in close proximity to the heated tank and components that are heated during normal operation, such as the exhaust and/or cabin. Line freezing shouldn't be an issue, as the exhaust system must be warm enough to vaporize the fluid to work. I've not heard of any issues of frozen lines, when the rest of the system is healthy. The system components are fairly standard, as many parts are universal across different makes and models.

[bd1028]

Dealer called said problem was egr coolant bypass valve. Keeping overnight had to order part.