DESCRIPTION
The speed sensor detects wheel speed and sends the appropriate signals to the skid control ECU (brake actuator assembly). These signals are used for brake control.
Skid control 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 (brake actuator assembly).
Tech Tips
When the connectors between the speed sensor and skid control ECU (brake actuator assembly) are connected, the following waveform is output.
| *1 | Speed Sensor | *2 | Skid Control Rotor |
| *a | Waveform (Reference): Between Speed Sensor (-) and Body Ground |
*b | Low speed |
| *c | High speed | - | - |
| DTC No. | Detection Item | DTC Detection Condition | Trouble Area |
|---|---|---|---|
| C1403 | Rear Speed Sensor RH Malfunction | Either of the following is detected:
|
|
| C1404 | Rear Speed Sensor LH Malfunction | Either of the following is detected:
|
|
PROCEDURE
CHECK REAR SPEED SENSOR INSTALLATION
Turn the ignition switch off.
| *a | Normal |
| *b | Abnormal |
| *c | Clearance |
Check the rear speed sensor installation.
| OK |
|---|
| There is no clearance between the sensor and the rear axle housing. |
| The installation bolt is tightened properly. |
| Result | |||
|---|---|---|---|
|
| NG |
|
INSTALL REAR SPEED SENSOR CORRECTLY Click here |
| OK |
|
INSPECT REAR SPEED SENSOR TIP
Remove the rear speed sensor.
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.
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.
Check the speed sensor signal after cleaning or replacement.
| Result | |||
|---|---|---|---|
|
| NG |
|
CLEAN OR REPLACE REAR SPEED SENSOR |
| OK |
|
INSPECT REAR AXLE SHAFT BEARING
Remove the rear axle shaft bearing.
Check the rear skid control rotor.
| OK |
|---|
| No scratches, oil, or foreign matter on the rotors. |
Tech Tips
The rear skid control rotor is incorporated into the rear axle shaft bearing.
If the rear skid control rotor needs to be replaced, replace it together with the rear axle shaft bearing.
Reinstall the rear axle shaft bearing.
for the rear speed sensor: Click here
for the rear axle shaft bearing: Click here
| Result | |||
|---|---|---|---|
|
| NG |
|
CLEAN OR REPLACE REAR AXLE SHAFT BEARING |
| OK |
|
READ VALUE USING GTS (REAR SPEED SENSOR)
Connect the GTS to the DLC3.
Start the engine.
Turn the GTS on.
Enter the following menus: Chassis / ABS/VSC/TRC / Data List.
According to the display on the GTS, read the Data List.
| Tester Display | Measurement Item | Range | Normal Condition | Diagnostic Note |
|---|---|---|---|---|
| RR Wheel Speed | Rear wheel speed sensor RH reading | Min.: 0 km/h (0 mph) Max.: 326.4 km/h (202 mph) |
Vehicle stopped: 0 km/h (0 mph) | When driving at constant speed: No large fluctuations |
| RL Wheel Speed | Rear wheel speed sensor RH reading | Min.: 0 km/h (0 mph) Max.: 326.4 km/h (202 mph) |
Vehicle stopped: 0 km/h (0 mph) | When driving at constant speed: No large fluctuations |
| Tester Display |
|---|
| RR Wheel Speed |
| RL Wheel Speed |
Check that there is no difference between the speed value output from the speed sensor displayed on the GTS and the speed value displayed on the speedometer when driving the vehicle.
Tech Tips
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.
| OK |
|---|
| The speed value output from the speed sensor displayed on the GTS is the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer). |
Tech Tips
If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step.
| Result | |||
|---|---|---|---|
|
| OK |
|
USE SIMULATION METHOD TO CHECK Click here |
| NG |
|
REPLACE REAR SPEED SENSOR
Turn the ignition switch off.
Replace the rear speed sensor.
Note
After replacing the speed sensor, perform a Test Mode (signal check) inspection sensor check.
| Result | ||
|---|---|---|
|
| NEXT |
|
RECONFIRM DTC
Clear the DTCs.
Turn the ignition switch off.
Start the engine.
Drive the vehicle at a speed of 40 km/h (25 mph) or more for at least 60 seconds.
Check if the same DTC is recorded.
| Result | |||
|---|---|---|---|
|
Tech Tips
The rear skid control rotor is incorporated into the rear axle shaft bearing.
If the rear skid control rotor needs to be replaced, replace it together with the rear axle shaft bearing.
| DTCs C1403 and C1404 are not output |
|
END |
| DTCs C1403 and/or C1404 are output |
|
REPLACE REAR AXLE SHAFT BEARING Click here |