C1608 on 2005-2020 Renault Clio — Electric Power Steering (EPS) Control Unit Internal Fault

C1608 is an OBD-II diagnostic trouble code meaning “Electric Power Steering (EPS) Control Unit Internal Fault.” C1608 is a manufacturer-specific chassis code used most prominently by Nissan/Infiniti and Renault, where it means the electric power steering (EPS) control unit has detected an internal malfunction in its own electronics. The EPS computer reads the steering torque sensor and vehicle speed, then drives an electric motor (integrated into the steering column on most affected models, such as the Renault Clio, Modus, Mégane and Twingo, where the code is also logged as DF002) to provide assist; when the unit's self-check fails, the system reduces or shuts off that assist. Drivers typically notice suddenly heavy or stiff steering — often intermittent at first — with the EPS warning light on, and Renault models commonly display a "Steering Fault" message instructing the driver to stop. The car remains mechanically steerable but takes much more effort, which is hazardous during parking maneuvers and emergency avoidance, and on Renaults the fault usually progresses to complete, permanent loss of assist requiring steering column or control unit replacement. Note that usage differs on some manufacturers: Mitsubishi defines C1608 as "Implausible diagnosis data" (unreliable stored failure memory in the ASC/brake control system), so confirm the definition for your specific make. This code is most commonly reported on 2005-2020 Renault Clio, with repair costs ranging from $700 to $1,800.