Thought it would be a good idea to post some information in this forum which will help owners of 2011 through 2013 LML Duramax powered pickups who are in Mexico, using the LSD diesel fuel. The sulfur content in the fuel is sufficient to temporarily "poison" the SCR and present the driver with a "Poor Quality Diesel Exhaust Fluid" message. (A few towns/cities do have ulsd, mainly near the border, but most of Mexico is still on lsd).
Before dealing with the LML, I should mention that the LMM (2007.5 through 2010) operates perfectly in Mexico, with the only symptom being an occasional blue smokey exhaust during regen as the sulfur compounds are burned out of the DPF. No permanent damage is done to the DPF unless higher sulfur fuel is used for more than 40,000 continuous miles, as proven by EPA and manufacturer testing prior to 2007.
Unfortunately, the SCR in the 2011 and later vehicles is very sensitive to sulfur poisoning, particularly as of the 2013 model year, when the EPA mandated more frequent NOX monitoring cycles, and less tolerance for variations in NOX. It is almost certain that anyone with a 2013 in Mexico will see the Poor Quality DEF message within a short time after starting to use Mexican fuel.
For the past 6 years I have been keeping a database of information, by staying in touch with a number of owners of different model years who take their vehicles into Mexico, and by extensive research of publicly available information about SCR operation and testing.
As a result, a straightforward method for inducing a regeneration has been found, which I have discussed in other forums, but never here.
Inducing a regeneration burns the sulfur compounds out of the SCR and returns emissions to normal. This in turn extinguishes the Poor Quality DEF message, and cancels the Check Engine code (if the Check Engine light also came on).
The steps necessary to induce a regeneration involve unplugging the DPF pressure sensors so that a default regeneration program kicks in. This program induces regeneration based on distance rather than pressure differential, at about twice the normal frequency.
Anyone needing detailed instructions, just drop me a Private Message.
Before dealing with the LML, I should mention that the LMM (2007.5 through 2010) operates perfectly in Mexico, with the only symptom being an occasional blue smokey exhaust during regen as the sulfur compounds are burned out of the DPF. No permanent damage is done to the DPF unless higher sulfur fuel is used for more than 40,000 continuous miles, as proven by EPA and manufacturer testing prior to 2007.
Unfortunately, the SCR in the 2011 and later vehicles is very sensitive to sulfur poisoning, particularly as of the 2013 model year, when the EPA mandated more frequent NOX monitoring cycles, and less tolerance for variations in NOX. It is almost certain that anyone with a 2013 in Mexico will see the Poor Quality DEF message within a short time after starting to use Mexican fuel.
For the past 6 years I have been keeping a database of information, by staying in touch with a number of owners of different model years who take their vehicles into Mexico, and by extensive research of publicly available information about SCR operation and testing.
As a result, a straightforward method for inducing a regeneration has been found, which I have discussed in other forums, but never here.
Inducing a regeneration burns the sulfur compounds out of the SCR and returns emissions to normal. This in turn extinguishes the Poor Quality DEF message, and cancels the Check Engine code (if the Check Engine light also came on).
The steps necessary to induce a regeneration involve unplugging the DPF pressure sensors so that a default regeneration program kicks in. This program induces regeneration based on distance rather than pressure differential, at about twice the normal frequency.
Anyone needing detailed instructions, just drop me a Private Message.
