Shop used Caterpillar 3126 Engine Control Modules (ECM) on MyLittleSalesman.com . Compare active listings with prices from $95 to $2,375. Sellers include CA Truck Parts, Rydemore Heavy Duty Truck Parts, DTI Truck Parts, and more. Filter by condition, price, or year to find the Caterpillar 3126 Engine Control Module (ECM) that fits your job.