The B1631 Code guide the engine for identifying the problem of the engine. As, this code is found in multiple brands of car, so is important to know the name of the name of manufacturer and model number of the car. Now it is very easy to get the meaning of the code. 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. 6 for Vehicle Speed Control and Idle Control System. 3 for Cruise Control Servo Indicates Low. 1 for TFP Valve Position Switch-Drive Without Drive Ratio.