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

1. Check the speed sensor installation.
   Fig 1: View Of Checking Front Speed Sensor Clearence

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

   There is no clearance between the sensor and the front steering knuckle.

NG → See step   4 

OK: Go to next step 

1. Connect the Techstream to the DLC3.
2. Start the engine.
3. Select the Data List on the Techstream. Refer to DATA LIST / ACTIVE TEST .
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   FR Wheel Speed	FR wheel speed sensor reading / min.: 0 km/h (0 mph), max.: 326.4 km/h (202 mph)	When vehicle is stopped: 0 km/h (0 mph) When vehicle is being driven at a constant speed: No major fluctuation	Similar speed as indicated on speedometer
   FL Wheel Speed	FL wheel speed sensor reading /min.: 0 km/h (0 mph), max.: 326.4 km/h (202 mph)	When vehicle is stopped: 0 km/h (0 mph) When vehicle is being driven at a constant speed: No major fluctuation	Similar speed as indicated on speedometer

4. Check the speed value output from the speed sensor displayed on the Techstream.

   HINT: 

   Factors that affect the indicated vehicle speed include tire size, tire inflation, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart. Refer to ON-VEHICLE INSPECTION .

   OK

   The speed value output from the speed sensor displayed on the Techstream is the similar speed as indicated on the speedometer.

   NOTE:

   Check the speed sensor signal after replacement. Refer to TEST MODE PROCEDURE

   HINT: 

   If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step. Refer to PROBLEM SYMPTOMS TABLE .

NG → REPLACE FRONT SPEED SENSOR AND FRONT SPEED SENSOR ROTOR 

OK → See step   3