SB18L002

SOME CUSTOMERS MAY EXPERIENCE AN ILLUMINATED MALFUNCTION INDICATOR LIGHT (MIL) WITH DTC P20EE DIESEL EXHAUST FLUID (DEF) SYSTEM NOx TRAP LOW EFFICIENCY SET WITHOUT AN APPARENT CAUSE. NEW CALIBRATIONS FOR THE DEF CONTROL UNIT (DCU) HAVE BEEN DEVELOPED TO ADDRESS THIS CONCERN. FOLLOW THE DIAGNOSTIC FOR THIS DTC. IF NO FAULT CAN BE FOUND WHEN PERFORMING THE NORMAL DIAGNOSIS, FOLLOW THE SERVICE PROCEDURE IN THIS BULLETIN TO REPROGRAM THE DEF CONTROL MODULE.