C1271

BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C1271,C1272,C1275,C1276: Low Output Signal of Front Speed Sensor RH (Test Mode DTC)
C1276 - Abnormal Change in Output Signal of Front Speed Sensor LH (Test Mode DTC)

DESCRIPTION

DTCs C1271 to C1276 will be cleared when the speed sensor sends a vehicle speed signal or when Test Mode ends. DTCs from C1271 to C1276 are output only in Test Mode.





HINT
* DTCs C1271 and C1275 are for the front speed sensor RH.
* DTCs C1272 and C1276 are for the front speed sensor LH.

WIRING DIAGRAM

Refer to DTCs C1401 and C1402 C1401.

INSPECTION PROCEDURE

NOTICE:
When replacing the brake actuator assembly, perform zero point calibration Component Tests and General Diagnostics.

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (FR/FL Speed Open)

(a) Using the Techstream, check for any momentary interruption in the wire harness and connector corresponding to the DTC Check For Intermittent Problems.

ABS/VSC/TRAC:





Result:





HINT
Perform the above inspection before removing the sensor and connector.

C -- CHECK FRONT SPEED SENSOR INSTALLATION

B -- READ VALUE USING TECHSTREAM (FR/FL WHEEL SPEED)
A -- Continue to next step.

2. REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU - FRONT SPEED SENSOR)

(a) Turn the ignition switch off.

(b) Repair or replace the harness or connector.

(c) Check for any momentary interruption between the skid control ECU and the front speed sensor Check For Intermittent Problems.

(d) Check that there are no momentary interruptions.

NEXT -- Continue to next step.

3. PERFORM TEST MODE (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 -- READ VALUE USING TECHSTREAM (FR/FL WHEEL SPEED)

OK -- END

4. READ VALUE USING TECHSTREAM (FR/FL WHEEL SPEED)

(a) Turn the ignition switch off.

(b) Connect the Techstream to the DLC3.

(c) Start the engine.

(d) Select the Data List mode on the Techstream Data List / Active Test.

ABS/VSC/TRAC:





(e) 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 Component Tests and General Diagnostics.

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).

NG -- CHECK FRONT SPEED SENSOR INSTALLATION
OK -- Continue to next step.

5. PERFORM TEST MODE (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 FRONT SPEED SENSOR INSTALLATION

OK -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) How To Proceed With Troubleshooting

6. CHECK FRONT SPEED SENSOR INSTALLATION

(a) Turn the ignition switch off.





(b) Check the speed sensor installation 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)

NG -- INSTALL FRONT SPEED SENSOR CORRECTLY Installation
OK -- Continue to next step.

7. CHECK FRONT SPEED SENSOR TIP

(a) Remove the front speed sensor Removal.

(b) Check the speed sensor tip.

OK:

No scratches, oil, or foreign matter on the sensor tip.

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.

8. CHECK FRONT SPEED SENSOR ROTOR

(a) Remove the front axle hub sub-assembly Removal.

(b) Check the speed sensor rotor.

OK:

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

NOTICE:
Check the speed sensor signal after cleaning or replacement Test Mode Procedure.

HINT
If the 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 (FRONT AXLE HUB SUB-ASSEMBLY)
OK -- Continue to next step.

9. INSPECT FRONT SPEED SENSOR

(a) Install the front speed sensor and front axle hub sub-assembly.





(b) Make sure that there is no looseness in the locking part and connecting part of the connector.

(c) Disconnect the front speed sensor connector.

(d) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

for RH
for LH










NOTICE:
Check the speed sensor signal after replacement Test Mode Procedure.

NG -- REPLACE FRONT SPEED SENSOR Removal
OK -- Continue to next step.

10. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - FRONT SPEED SENSOR)

(a) Make sure that there is no looseness in the locking part and connecting part of the connector.





(b) Disconnect the skid control ECU connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

for RH
for LH










NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

11. INSPECT SKID CONTROL ECU (SENSOR INPUT)

(a) Reconnect the skid control ECU connector.





(b) Turn the ignition switch to ON.

(c) Measure the voltage according to the value(s) in the table below.

Standard Voltage:

for RH
for LH










NG -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal
OK -- Continue to next step.

12. PERFORM TEST MODE (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 -- REPLACE FRONT SPEED SENSOR

OK -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION) How To Proceed With Troubleshooting

13. REPLACE FRONT SPEED SENSOR

(a) Turn the ignition switch off.

(b) Replace the front speed sensor Removal.

NOTICE:
Check the speed sensor signal after replacement Test Mode Procedure.

NEXT -- Continue to next step.

14. PERFORM TEST MODE (SIGNAL CHECK)

(a) Perform the sensor check in the Test Mode procedure Test Mode Procedure.

OK:

All Test Mode DTCs are cleared.

NG -- REPLACE FRONT SPEED SENSOR ROTOR

OK -- END

15. REPLACE FRONT SPEED SENSOR ROTOR

(a) Turn the ignition switch off.

(b) Replace the front axle hub sub-assembly (front speed sensor rotor) Removal.

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

NOTICE:
Check the speed sensor signal after replacement Test Mode Procedure.

NEXT -- Continue to next step.

16. PERFORM TEST MODE (SIGNAL CHECK)

(a) Perform the sensor check in the Test Mode procedure Test Mode Procedure.

OK:

All Test Mode DTCs are cleared.

NG -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal

OK -- END