The dictionary meaning of the B2123 Code helps to get basic idea about the engine problem. The basic meaning of the dictionary meaning is found online but for real meaning of the code, you have to depend on the manual of the router. The dictionary meaning of the code is b for Body Code Problem is antilock brake system, electronic suspension and steering systems. 2 for MFG – Manufacturer Specific. 1 for Transmission. 2 for Air Conditioning (A/C) Clutch Feedback Circuit High Voltage and 3 for Transmission Control Module Reprogrammable Memory. Know the manufacturer name and model number to get the real meaning of the code.