To properly maintain the HMMWV, what should be referenced for procedures?

The PMCS (Preventive Maintenance Checks and Services) procedures book is the correct reference for maintaining the HMMWV. This book provides detailed guidelines on the necessary checks, services, and maintenance tasks required to ensure that the vehicle operates effectively and safely. Following the procedures outlined in this book helps to identify potential issues before they become serious problems, ensuring the longevity and reliability of the vehicle.

The other options, while they may provide useful information, do not serve the specific purpose of outlining the maintenance protocols for the HMMWV like the PMCS procedures book does. The field manual contains broader operational guidelines; the operations manual focuses on the use of the vehicle rather than maintenance, and the service bulletins may provide specific updates or notices but are not comprehensive in covering routine maintenance procedures. Therefore, for routine HMMWV upkeep, the PMCS procedures book stands out as the essential reference.