The dictionary meaning of the B1784 Code 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. 4 for Cruise Vehicle Speed or Set Speed Difference Too High. However, this meaning of the code is not enough. For getting the real meaning of the code, it is necessary to read the manual to know the manufacturer name and model number. As the code has started with the B, the body of the engine has the main problem.