25-002-13

MIL Illumination Due To P1C56 - NOx Sensor Intermittent - Bank 1 Sensor 2 This bulletin involves verifying excessive Diesel Exhaust Fluid (DEF) deposits in the decomposition tube collected and if present, replacing the Catalytic Converter Shield with a ?clam shell? shield with a metal exterior.This repair is to be performed in addition to diagnostics available in DEALERCONNECT > Service > Repair Information > TechCONNECT > 28 - DTC-Based Diagnostics > MODULE, Powertrain Control (PCM), DD/DP - Chassis Cab > Diagnosis and Testing > P1C56 - NOx SENSOR INTERMITTENT - BANK 1 SENSOR 2 Customer may experience MIL illumination. Further investigation by the technician may find P1C56 - NOx Sensor Intermittent - Bank 1 Sensor 2 is set active or stored.This condition may be caused by insufficient heat retention in the exhaust at or near the DEF doser.