DTC C1401 Front Speed Sensor RH Malfunction; DTC C1402 Front Speed Sensor LH Malfunction: Description

The speed sensor detects wheel speed and sends the appropriate signals to the skid control ECU. These signals are used for ABS/VSC/TRAC control.

Speed sensor rotors have rows of alternating N and S magnetic poles, and their magnetic fields change when the rotors turn.

Each speed sensor detects that magnetic change and sends a pulse signal to the skid control ECU.

Fig 1: Identifying Speed Sensor Rotor And Speed Sensor

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

DTC DETECTION CONDITION CHART

DTC Code	DTC Detection Condition	Trouble Area
C1401 C1402	Any of the following is detected: At a vehicle speed 10 km/h (6 mph) or more, output voltage from one of the speed sensors is less than that from the other sensors for 15 seconds or more (for 2WD) or for 30 seconds or more (for 4WD). At a vehicle speed less than 10 km/h (6 mph), output from one of the speed sensors is 0 km/h (0 mph) for 1 second or more. At a vehicle speed 10 km/h (6 mph) or more, outputs from both front speed sensors are 0 km/h (0 mph) for 15 seconds or more (for 2WD) or for 30 seconds or more (for 4WD).	Front speed sensor RH/LH Speed sensor rotor

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