The B2131 Code has double meaning in general. Once meaning is from automobile dictionary and another meaning is according to the manufacturer and model of the car what is genuine mening. An engineer needs the real meaning of the code what explains the problem. The same code is found in different brands of car and those codes are generally set by the manufacturer according to model number. If the real meaning is not used for identifying the car engine, you cannot solve the problem. The dictionary meaning of the code can easily find online. You can use any search engine to know the meaning of the code.