DTC C15A4/64: Motor Rotation Angle Malfunction; DTC C15A9/66: Lock Holder Deviation Detection; DTC C15AA/66: Lock Mechanism Release Incomplete; DTC C15AB/66: Lock Mechanism Insertion [09/2014 - 09/2020]: Description

When the VGRS system is normal, the steering actuator assembly conducts current from the VGRS ECU (front steering control ECU) to the steering actuator solenoid to release the lock mechanism, enabling motor operation.

The steering actuator assembly does not operate under any of the following conditions:

The engine switch is off.
The motor in the actuator is locked by the lock mechanism to prevent rotation (fail-safe function).
The system is being protected from overheating (fail-safe function).

If the VGRS ECU (front steering control ECU) detects a malfunction in the steering actuator lock mechanism or a motor rotation angle error, it stores these DTCs.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	Warning Indicate	Return-to-normal Condition
C15A4/64	Motor Rotation Angle Malfunction	After starting the engine, the "Actuator Target Angle" and "Actuator Angle" have a difference of 0.5 degrees or more for 1 second or more.	Steering actuator assembly	Comes on	Engine switch on (IG) again
C15A9/66	Lock Holder Deviation Detection	After the engine switch is turned off, the lock pin is inserted with the steering wheel near the neutral position (within 90 degrees of 0), the "Actuator Angle" and "Deep Groove Electrical Angle Position" are at 40 degrees or more	Steering actuator assembly	Comes on	After clearing DTCs, perform actuator angle neutral point calibration.
C15AA/66	Lock Mechanism Release Incomplete	After starting the engine, the "Motor q Axis Target Voltage" is 1.8 V or higher and 15 seconds or more elapse, or the "Motor q Axis Target Voltage" is 0.6 V or higher and 180 seconds or more elapse.	Steering actuator assembly	Comes on	After clearing DTCs, perform actuator angle neutral point calibration.
C15AB/66	Lock Mechanism Insertion	After the engine switch is turned on (IG), when the motor is operating to confirm the lock pin insertion, the "Motor q Axis Target Voltage" is below 2 V.	Steering actuator assembly	Comes on	After clearing DTCs, perform actuator angle neutral point calibration.