Thy engine B1674 Code may come when your car engine has problem and the engine is verifying by the engine code reader. You should be careful with the faulty car and until fix the problem of the engine, you should not drive the car. Before fixing the problem, you need to read the manual if you have all necessary machineries for solving the problem of the engine. From the code, the dictionary meaning is B for Body Code Problem is antilock brake system, electronic suspension and steering systems. 1 for MFG – Manufacturer Specific. 6 for Vehicle Speed Control and Idle Control System. 7 for Vehicle Speed Output Circuit and 4 for Cruise Vehicle Speed and Set Speed Difference Too High.