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: Procedure

1. Turn the ignition switch off.
2. Check the speed sensor installation.
   Fig 1: Checking Speed Sensor Installation

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   OK

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

   The installation bolt is tightened properly.

   Torque 

   8.5 N*m (87 kgf*cm, 75 in.*lbf)

   TEXT IN ILLUSTRATION
   
   

   *a	OK
   *b	NG
   *c	Clearance

NG → See step   8 

OK: Go to next step 

1. Remove the front speed sensor. Refer to REMOVAL .
2. Check the speed sensor tip.

   OK

   No scratches, oil, or foreign matter on the sensor tip.

   NOTE:

   If no damage to the speed sensor tip is found during this inspection, do not replace the speed sensor.

   HINT: 

   If there is iron powder sticking to the rotor, this will result in a malfunction, so confirm that the rotor is not contaminated with foreign material before replacing the sensor.

NG → CLEAN OR REPLACE FRONT SPEED SENSOR 

OK: Go to next step 

1. Remove the front speed sensor rotor. Refer to REMOVAL .
2. Check the speed sensor rotor.

   OK

   No scratches, oil, or foreign matter on the rotors.

   HINT: 

   The front speed sensor rotor is incorporated into the front axle hub bearing.

NG → CLEAN OR REPLACE FRONT SPEED SENSOR ROTOR 

OK: Go to next step 

1. Install the front speed sensor and the front speed sensor rotor.
2. Connect the Techstream to the DLC3.
3. Turn the ignition switch to ON.
4. Turn the Techstream on.
5. Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.
6. According to the display on the Techstream, read the Data List.
   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 km/h (202 mph)	Actual wheel speed	Similar speed as indicated on speedometer
   FL Wheel Speed	FL wheel speed sensor reading /min.: 0 km/h (0 mph), max.: 326 km/h (202 mph)	Actual wheel speed	Similar speed as indicated on speedometer

7. Check that there is no difference between the speed value output from the speed sensor displayed on the Techstream and the speed value displayed on the speedometer when driving the vehicle.

   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 same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).

   HINT: 

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

NG → See step   5 

OK → See step   7 

1. Turn the ignition switch off.
2. Replace the front speed sensor. Refer to REMOVAL .

NEXT: Go to next step 

1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
2. Start the engine.
3. Drive the vehicle at a speed of 40 km/h (25 mph) or more for at least 60 seconds.
4. Check if the same DTC is recorded. Refer to DTC CHECK / CLEAR .
   RESULT
   
   

   Result	Proceed to
   DTCs (C1401 and C1402) are not output	A
   DTCs (C1401 and/or C1402) are output	B

   HINT: 

   • The front speed sensor rotor is incorporated into the front axle hub bearing.
   • If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step. Refer to PROBLEM SYMPTOMS TABLE .

B → See step   9 

A → END