DTC C1401: Front Speed Sensor RH Malfunction; DTC C1271: Low Output Signal of Front Speed Sensor RH (Test Mode DTC); DTC C1272: Low Output Signal of Front Speed Sensor LH (Test Mode DTC); DTC C1402: Front Speed Sensor LH Malfunction [08/2014 - ]: Description

The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU. These signals are used for brake control.

The 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 And Signal Graph

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

DTC Code	DTC Detection Condition	Trouble Area
C1401 C1402	One of the following conditions is met: At a vehicle speed of 10 km/h (6 mph) or more, the output voltage from one of the speed sensors is less than that from the other sensors for 15 seconds or more. At a vehicle speed of less than 10 km/h (6 mph), the output from one of the speed sensors is 0 km/h (0 mph) for 1 second or more. At a vehicle speed of 10 km/h (6 mph) or more, the outputs from both front speed sensors are 0 km/h (0 mph) for 15 seconds or more.	Front speed sensor RH/LH Speed sensor rotor Sensor installation
C1271 C1272	Stored only during test mode.	Front speed sensor RH/LH Speed sensor rotor Sensor installation

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