EPS SYSTEM: Fail-safe (4WAS Main Control Unit)

EPS system (4WAS main control unit) enters the fail-safe mode (that allows the steering force to be controlled without impairing the drive ability) if the input from each sensor is not within the specified range. Then, 4WAS warning lamp turns ON.

Fig 1: Identifying Solenoid Valve Voltage Versus Engine Speed Graph
Courtesy of NISSAN NORTH AMERICA, INC.

DTC	Error part and root cause	Contents of fail-safe
C1919	Malfunction is detected in vehicle speed signal that is output from ABS actuator and electric unit (control unit) via CAN communication. (Improper signal inputs while driving.)	Allows the steering force to be controlled without impairing the drive ability.