The B1786 Code is associated with the faulty engine and it is essential to resolve the problem. The dictionary meaning of the code is necessary to know and the dictionary meaning is B for Body Code Problem is antilock brake system, electronic suspension and steering systems. 1 for MFG – Manufacturer Specific. 7 for Auxiliary Emission Controls. 8 for Exhaust Gas Recirculation System Valve one and 6 for Cruise Control System – Vehicle Accel Too High. You need to solve the problem by the professional and do not try to solve the problem if you do not know how to solve the problem.