RepairPal Certified shops can diagnose and repair your 2012 Nissan TITAN. They provide transparent pricing with a minimum 12-month or 12,000-mile warranty on repairs and services.
You need to ensure you have a proper charge. A low charge will cause it not to kick on. Could also be a pressure sensor issue. Gauges are needed.
Use this link to find a good shop near you.
https://repairpal.com/repair-shops
Alex