Engie device is an OBD (Onboard Diagnostic System) model II 1,5 device. This system uses a standard format to describe malfunctions called DTC (Diagnostic Trouble code).
DTC's are 4-digit, preceded by a letter:
P for power-train: Engine, transmission and emissions systems.
B for body: Climate control system, lighting, airbags, etc.
C for chassis: Electronic suspension and steering systems.
U for a network: Controller area network wiring bus and modules.
OBD-II standardization was created by SAE International to simplify diagnosis and most manufacturers have made it the main connector in the vehicle through which all systems are diagnosed and reprogrammed.
Manufacturers may also add custom data parameters to their specific OBD-II implementation, including real-time data requests as well as trouble codes. Codes of this nature are not always detected by OBD devices.