The B1939 Code explains the general meaning as well as real meaning but for the real meaning of the code, you need to know more information like manufacturer name and model number. Manufacturer sets the code for engine and it is easy to fix the problem from the engine when you will get the real meaning. The general meaning of the code is dictionary meaning and it is found as B for Body Code Problem is antilock brake system, electronic suspension and steering systems. 1 for MFG – Manufacturer Specific. 9 for Fuel and Air Metering. 3 for Cruise Control Servo Indicates Low and 9 for Kick-Down Switch Failed Short.