The B1263 Code error comes for the engine body problem what is necessary to fix. The meaning of the code can be understood if the technician reads manual and know the model and manufacturer of the car. The meaning of the code also differs. However, the B1263 Code has dictionary meaning and meaning of the code is B for Body Code Problem is antilock brake system, electronic suspension and steering systems. 1 for MFG – Manufacturer Specific. 2 for Accelerator Pedal Position Sensor one performance, 6 for Control Module Throttle Actuator Position Performance and 3 for Transmission Control Module Reprogrammable Memory.