C1466
BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1466/33, C1273/73, C1274/74, C1467/34: Rear Speed Sensor RH Circuit
C1467/34 - Rear Speed Sensor LH Circuit
DESCRIPTION
The speed sensor detects the wheel speed and sends the appropriate signals to the skid control ECU. These signals are used for ABS control.
DTCs C1273/73 and C1274/74 can be cleared when the speed sensor sends a wheel speed signal or when Test Mode ends. DTCs C1273/73 and C1274/74 are output only in Test Mode.
HINT
When the connectors between the speed sensor and skid control ECU are connected, the following waveform is output.
HINT
* DTCs C1466/33 and C1273/73 are for the rear speed sensor RH.
* DTCs C1467/34 and C1274/74 are for the rear speed sensor LH.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTICE:
When replacing the skid control ECU, perform initialization and calibration of the linear solenoid valve Initialization.
PROCEDURE
1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)
(a) Using the Techstream, check for any momentary interruptions in the wire harness and connector corresponding to a DTC Check For Intermittent Problems.
ABS/VSC/TRAC
OK:
There are no momentary interruptions.
HINT
Perform the above inspection before removing the sensor and connector.
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2. READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)
(a) Select the Data List on the Techstream Data List / Active Test.
ABS/VSC/TRAC
(b) 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 Reference Chart On-Vehicle inspection.
OK:
The speed value output from the speed sensor displayed on the Techstream is similar to the speed indicated on the speedometer.
NG -- CHECK REAR SPEED SENSOR INSTALLATION
OK -- Continue to next step.
3. PERFORM TEST MODE INSPECTION (SIGNAL CHECK)
(a) Turn the ignition switch off.
(b) Perform the sensor check in the Test Mode procedure Test Mode Procedure.
OK:
All Test Mode DTCs are cleared.
NG -- CHECK REAR SPEED SENSOR INSTALLATION
OK -- Continue to next step.
4. RECONFIRM DTC
(a) Turn the ignition switch off.
(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(c) Turn the ignition switch to ON (READY).
(d) Drive the vehicle at a speed of 10 km/h (6 mph) or more for at least 60 seconds.
(e) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.
Result:
HINT
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next suspected area Problem Symptoms Table.
B -- CHECK REAR SPEED SENSOR AND REAR SPEED SENSOR ROTOR SERRATIONS
A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting
5. CHECK REAR SPEED SENSOR INSTALLATION
(a) Turn the ignition switch off.
(b) Check the speed sensor installation.
OK:
There is no clearance between the sensor and the rear axle carrier.
The installation bolt is tightened properly Installation.
NG -- INSTALL REAR SPEED SENSOR CORRECTLY Installation
OK -- Continue to next step.
6. CHECK REAR SPEED SENSOR TIP AND REAR SPEED SENSOR ROTOR
(a) Remove the rear speed sensor and rear speed sensor rotor Removal and Removal).
(b) Check the speed sensor tip and rear speed sensor rotor.
OK:
The sensor tip and rotor are free of scratches, oil, and foreign matter.
HINT
If the rear speed sensor rotor needs to be replaced, replace it together with the outboard joint shaft assembly.
NOTICE:
* If no damage to the speed sensor tip is found during this inspection, do not replace the speed sensor.
* Check the speed sensor signal after cleaning or replacement Test Mode Procedure.
NG -- CLEAN OR REPLACE REAR SPEED SENSOR OR REAR SPEED SENSOR ROTOR
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - REAR SPEED SENSOR)
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(b) Disconnect the A44 or A45 skid control ECU connector and the rear speed sensor connector.
(c) Measure the resistance according to the value(s) in the table below.
Standard Resistance:
for RH
for LH
Text in Illustration
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
8. CHECK REAR SPEED SENSOR AND REAR SPEED SENSOR ROTOR SERRATIONS
(a) Turn the ignition switch off.
(b) Reconnect the skid control ECU connectors and the rear speed sensor connectors.
(c) Connect an oscilloscope to the rear speed sensor terminal of the skid control ECU and body ground.
(d) Check the waveform output when the wheels are rotated.
OK:
The same waveform is output from all the sensors and there is no noise or interference in the waveform.
Text in Illustration
HINT
* As the vehicle speed (wheel revolution speed) increases, the wavelength shortens.
* When noise is identified in the waveform on the oscilloscope, the erratic signals are generated due to speed sensor rotor scratches, looseness or attached foreign matter.
NOTICE:
Check the speed sensor signal after cleaning or replacement Test Mode Procedure.
HINT
If the rear speed sensor rotor needs to be replaced, replace it together with the outboard joint shaft assembly.
NG -- CLEAN OR REPLACE REAR SPEED SENSOR OR REAR SPEED SENSOR ROTOR
OK -- Continue to next step.
9. RECONFIRM DTC
(a) Turn the ignition switch off.
(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(c) Turn the ignition switch to ON (READY).
(d) Drive the vehicle at a speed of 10 km/h (6 mph) or more for at least 60 seconds.
(e) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.
Result:
HINT
If troubleshooting has been carried out according to Problem Symptoms Table, refer back to the table and proceed to the next suspected area Problem Symptoms Table.
B -- REPLACE SKID CONTROL ECU Removal
A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting