Used for diagnostic purposes when testing for various voltage values within the vehicle’s Engine Control Module (ECM). Includes x1 Chassis Harness p/n: 12-801-05-01, Chassis Overlay p/n: 12-801-05-02, x1 Engine Harness p/n: 12-801-05-03, Engine Overlay p/n: 12-801-05-04 and x2 Nylon Bags p/n: 12-801-01-11.