Up to 08/2009
BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C0200/31,C0205/32,C1271/71,C1272/72: Front Speed Sensor RH Circuit
C1272/72 - Low Output Signal of Front Speed Sensor LH (Test Mode DTC)
DESCRIPTION
The speed sensor detects wheel speed and sends the appropriate signals to the skid control ECU. These signals are used for ABS control.
DTCs C1271/71 and C1272/72 can be cleared when the speed sensor sends a wheel speed signal or when Test Mode ends. DTCs C1271/71 and C1272/72 are output only in Test Mode.
HINT
* DTCs C0200/31 and C1271/71 are for the front speed sensor RH.
* DTCs C0205/32 and C1272/72 are for the front 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 (FRONT SPEED SENSOR)
(a) Select the Data List on the Techstream Data List / Active Test.
ABS/VSC/TRAC
(b) Check that 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 the similar speed as indicated on the speedometer.
NG -- CHECK FRONT SPEED SENSOR INSTALLATION
OK -- Continue to next step.
3. PERFORM TEST MODE INSPECTION (SIGNAL CHECK)
(a) Turn the power switch off.
(b) Perform the sensor check in the Test Mode procedure Test Mode Procedure.
OK:
All Test Mode DTCs are cleared.
NG -- CHECK FRONT SPEED SENSOR INSTALLATION
OK -- Continue to next step.
4. RECONFIRM DTC
(a) Turn the power switch off.
(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(c) Turn the power switch 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 step Problem Symptoms Table.
B -- CHECK FRONT SPEED SENSOR AND FRONT SPEED SENSOR ROTOR SERRATIONS
A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting
5. CHECK FRONT SPEED SENSOR INSTALLATION
(a) Turn the power switch off.
(b) 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
8.0 N*m (82 kgf*cm, 71 in.*lbf)
NG -- INSTALL FRONT SPEED SENSOR CORRECTLY Installation
OK -- Continue to next step.
6. CHECK FRONT SPEED SENSOR TIP
(a) Remove the front speed sensor Removal.
(b) Check the speed sensor tip.
OK:
The sensor tip is free of scratches, oil, and foreign matter.
NOTICE:
Check the speed sensor signal after cleaning or replacement Test Mode Procedure.
NG -- CLEAN OR REPLACE FRONT SPEED SENSOR
OK -- Continue to next step.
7. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - FRONT SPEED SENSOR)
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(b) Disconnect the skid control ECU connectors and the front 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 FRONT SPEED SENSOR AND FRONT SPEED SENSOR ROTOR SERRATIONS
(a) Turn the power switch off.
(b) Reconnect the skid control ECU connectors and the front speed sensor connectors.
(c) Connect an oscilloscope to the front 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.
HINT
* As the vehicle speed (wheel revolution speed) increases, a cycle of the waveform narrows.
* When noise is identified in the waveform on the oscilloscope, the erratic signals are generated due to speed sensor rotor scratches, looseness or foreign matter attached to it.
Text in Illustration
NOTICE:
Check the speed sensor signal after cleaning or replacement Test Mode Procedure.
HINT
If the front speed sensor rotor needs to be replaced, replace it together with the front drive outboard joint shaft assembly.
NG -- CLEAN OR REPLACE FRONT SPEED SENSOR OR FRONT SPEED SENSOR ROTOR
OK -- Continue to next step.
9. RECONFIRM DTC
(a) Turn the power switch off.
(b) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(c) Turn the power switch 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 step Problem Symptoms Table.
B -- REPLACE SKID CONTROL ECU Removal
A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting