A repair for many potential issues with various 2020–2024 Chevrolet vehicles,
such as the Silverado pickup truck, Tahoe SUV, and Suburban SUV, which are brought
by a failing Duramax DEF sensor, is detailed in a service bulletin that GM has reprinted.
Three separate Duramax diesel engines—available in three different configurations
for the Chevy Silverado, Tahoe, and Suburban—power all of the vehicles in question.
Affected Chevy Silverado, Tahoe, and Suburban cars with Duramax engines may have inaccurate
readings, erratic operation, or a jammed DEF level sensor. The diesel exhaust fluid (DEF) l
Lower torque in diesel engines may sometimes result from DEF sensor faults; however,
GM does not state if this issue is present in this particular example.
Additional signs of a malfunctioning DEF level sensor might include the Malfunction
Indicator Lamp (MIL) staying on or the driver information center (DIC) showing the warning message "
"DEF Level Low" or the warning message "Service Emission System," or both.