What does it mean?
OBD II fault code is a manufacturer specific code that is defined by car maker Ford as U1262 – “SCP (J1850) Communication Bus Fault”, or sometimes as “SCP (J1850) Communication Bus Fault – Instrument Cluster” and is set when the PCM (Powertrain Control Module) detects a communication failure between itself and HEC (Hybrid Electronic Cluster).
Note that “SCP” in this definition means “Serial Communications Protocol”, which is Ford’s interpretation of the SAE (Society of Automotive Engineers) J1850 standard. In simple terms, Serial Communication Protocol refers to the flow of data across a network that is more commonly referred to as a “bus”. In this case, the bus is the communication system across which the PCM delivers input data to all the instruments, warning lights, and other indicators on the instrument cluster.
Typical information that flows across the bus involves vehicle speed, RPM (engine speed), engine/transmission temperatures, system voltages, and warning lights that indicate the status of various systems and features that may be fitted to the particular application. The image below shows part of a typical Ford instrument cluster printed circuit. Note that apart from replacing this circuit board, it is generally not possible to repair Ford instrument clusters on a DIY basis.