IF YOU CONFIRM The MIL is ON with DTC P0101 (MAF SEN/CIRCUIT-B1) stored, and There are no drivability issues. ACTION 1. Refer to step 6 in the SERVICE PROCEDURE to confirm this bulletin applies to the vehicle you are working on. 2. If this bulletin applies, reprogram the ECM. NOTE: If this bulletin does apply (the ECM needs to be reprogrammed), DO NOT replace the mass air flow sensor. See this bulletin for further detail.