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. Refer to INSTALLATION .

   OK

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

   The installation bolt is tightened properly.

NG → See step   7 

OK: Go to next step 

NG → CLEAN OR REPLACE FRONT SPEED SENSOR 

OK: Go to next step 

1. Remove the front axle hub sub-assembly. Refer to REMOVAL .
2. Check the speed sensor rotor.

   OK

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

   NOTE:

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

   HINT: 

   If the front speed sensor rotor needs to be replaced, replace it together with the front axle hub sub-assembly.

NG → CLEAN OR REPLACE FRONT SPEED SENSOR ROTOR 

OK: Go to next step 

1. Turn the ignition switch off.
2. Connect the Techstream to the DLC3.
3. Start the engine.
4. Turn the Techstream on.
5. Enter the following menus: Chassis / ABS/VSC/TRAC / Data List.
   ABS/VSC/TRAC
   
   

   Tester Display	Measurement Item/Range	Normal Condition	Diagnostic Note
   FR Wheel Speed	Front speed sensor RH reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph)	Vehicle stopped: 0 km/h (0 mph)	No large fluctuations when driving at a constant speed.
   FL Wheel Speed	Front speed sensor LH reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph)	Vehicle stopped: 0 km/h (0 mph)	No large fluctuations when driving at a constant speed.

6. 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 OPERATION CHECK .

   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 Problem Symptoms Table, refer back to the table and proceed to the next suspected area. Refer to PROBLEM SYMPTOMS TABLE .

NG → See step   5 

OK → See step   8 

1. Replace the front speed sensor. Refer to REMOVAL .
   NOTE:

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

NEXT: Go to next step 

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

   NOTE:

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

   HINT: 

   • If the front speed sensor rotor needs to be replaced, replace it together with the front axle hub sub-assembly.
   • If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next suspected area. Refer to PROBLEM SYMPTOMS TABLE .

B → See step   9 

A → END