- At a vehicle speed of 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.
- 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 of 10 km/h (6 mph) or more, outputs from both front speed sensors are 0 km/h (0 mph) for 15 seconds or more.
| Last Modified: 04-05-2023 | 6.11:8.1.0 | Doc ID: RM1000000018KEF |
| Model Year Start: 2018 | Model: Sienna | Prod Date Range: [11/2017 - ] |
| Title: BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: VEHICLE STABILITY CONTROL SYSTEM: C1401,C1402; Front Speed Sensor RH Malfunction; 2018 - 2020 MY Sienna [11/2017 - ] | ||
|
DTC |
C1401 |
Front Speed Sensor RH Malfunction |
|
DTC |
C1402 |
Front Speed Sensor LH Malfunction |
DESCRIPTION
Each speed sensor detects wheel speed and sends signals to the skid control ECU (brake actuator assembly). These signals are used by the ABS control system.
The speed sensor rotors have 48 serrations. Hall IC type speed sensors use the frequency of output pulses to detect the vehicle speed. Because the sensor outputs digital pulses, it can detect the vehicle speed even when the vehicle is nearly stationary.
HINT:
Check the connection status between the sensor connector and the vehicle wire harness.
|
DTC No. |
DTC Detection Condition |
Trouble Area |
|---|---|---|
|
C1401 C1402 |
Any of the following is detected: |
|
HINT:
- DTC C1401 is for the front speed sensor RH.
- DTC C1402 is for the front speed sensor LH.
PROCEDURE
|
1. |
CHECK FRONT SPEED SENSOR INSTALLATION |
|
(a) Check the speed sensor installation. 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
|
|
| NG |
|
|
|
2. |
INSPECT FRONT SPEED SENSOR AND SENSOR ROTOR |
(a) Remove the front speed sensor and the component with the sensor rotor (See page
![2016 - 2020 MY Sienna [12/2015 - ]; BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: FRONT SPEED SENSOR: REMOVAL](/t3Portal/stylegraphics/info.gif)
for speed sensor, and
for sensor rotor).
(b) Check the speed sensor tip and speed sensor rotor.
OK:
No scratches, oil, or foreign matter on the sensor tip and rotor.
NOTICE:
-
If no damage to the speed sensor tip is found during this inspection, do not replace the speed sensor.
If there are any ferrous metal filings stuck to the rotor, this will result in a malfunction, so confirm that the rotor is not contaminated with foreign matter before replacing the sensor.
-
Check the speed sensor signal after cleaning or replacement (See page
).
| NG |
|
CLEAN OR REPLACE FRONT SPEED SENSOR OR COMPONENT WITH SENSOR ROTOR |
|
|
3. |
READ VALUE USING TECHSTREAM (FRONT SPEED SENSOR) |
(a) Install the front speed sensor and the component with the sensor rotor.
(b) Connect the Techstream to the DLC3.
(c) Start the engine.
(d) Select the Data List using the Techstream (See page
).
ABS/VSC/TRAC
|
Tester Display |
Measurement Item/Range |
Normal Condition |
Diagnostic Note |
|---|---|---|---|
|
FR Wheel Speed |
Front wheel speed sensor RH reading / Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph) |
Vehicle stopped: 0 km/h (0 mph) |
When driving at constant speed: No large fluctuations |
|
FL Wheel Speed |
Front wheel speed sensor LH reading / Min.: 0 km/h (0 mph), Max.: 326 km/h (202 mph) |
Vehicle stopped: 0 km/h (0 mph) |
When driving at constant speed: No large fluctuations |
(e) 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 pressure, 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 (See page
).
OK:
The speed value output from the speed sensor displayed on the Techstream is similar to the speed indicated on the speedometer.
| OK |
|
|
|
4. |
REPLACE FRONT SPEED SENSOR RH |
(a) Turn the ignition switch off.
(b) Replace the front speed sensor (See page
).
NOTICE:
Check the speed sensor signal after replacement (See page
).
|
|
5. |
RECONFIRM DTC |
(a) Clear the DTCs (See page
).
(b) Turn the ignition switch off.
(c) Start the engine.
(d) Drive the vehicle at a speed of 40 km/h (25 mph) or more for at least 60 seconds.
(e) Check if the same DTC is output (See page
).
|
Result |
Proceed to |
|---|---|
|
DTCs C1401 and C1402 are not output. |
A |
|
DTCs C1401 and/or C1402 are output. |
B |
NOTICE:
Check the speed sensor signal after replacement (See page
).
HINT:
- If the front speed sensor rotor needs to be replaced, replace the front drive outboard joint shaft assembly.
-
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next step before replacing parts (See page
).
| A |
|
END |
| B |
|
|
|