The engine B1789 Code is related with the engine and if the problem of the engine is not solved, you cannot drive the car. You can solve the problem form the engine by the professional. It is necessary some expensive machines for solving the problem from the engine. The dictionary meaning of the 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 and 9 for Kick-Down Switch Failed Short. After solving the problem from the engine, it is necessary to take car for test drive.