MID 128-PID 84 MID 128-PID 84 MID 128 PID 84 — ROAD SPEED Failure Mode Identifier (FMI): 9 (Abnormal update rate) Parameter Identification (PID): P84 Message Identification (MID): 128 FMI 9 Abnormal update rate Conditions for fault code: Missing signal from VECU Possible causes: J1708 vehicle speed message does not exist, (VECU error) Reaction from Engine Management System (EMS) Module: MIL lamp illuminated Noticeable external symptoms: Engine derate Page 23 MID 128-PID 84