Shop used Caterpillar 3126 Engine Control Modules (ECM) on MyLittleSalesman.com . Compare active listings with prices from $95 to $2,375. Sellers include Vander Haag's, Holst Truck Parts, Camions Gilbert, and more. Filter by condition, price, or year to find the Caterpillar 3126 Engine Control Module (ECM) that fits your job.