The engine B1845 Code comes up when the engine of the car has a related problem. The problem from the engine is necessary to solve and you can solve the problem if you have all necessary tools, machineries and experience. The manufacturer name and model number are also necessary to solve the problem. 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. 8 for Ignition System or Misfire. 4 for BBV Sensor Circuit Low Voltage and 5 for Park or Neutral Position (PNP) Switch Circuit Engine Torque Signal Circuit.