Electronically Controlled Brake System

BRAKE CONTROL / DYNAMIC CONTROL SYSTEMS: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1235/35,C1236/36,C1238/38,C1239/39,C1275/75-C1278/78: Foreign Object is Attached on Tip of Front Speed Sensor RH
C1278/78 - Abnormal Change in Output Signal of Rear Speed Sensor LH (Test Mode DTC)

DESCRIPTION

When foreign matter adheres to the speed sensor tip or speed sensor rotor, these DTCs are output. An abnormal waveform input from the sensor determines these conditions.

These DTCs may be detected when a malfunction occurs in the connector terminals or wire harness of the speed sensor circuit.

DTCs C1275/75 to C1278/78 will be cleared when the speed sensor sends a wheel speed signal or when Test Mode ends. DTCs from C1275/75 to C1278/78 are output only in Test Mode.





HINT
* DTCs C1235/35 and C1275/75 are for the front speed sensor RH.
* DTCs C1236/36 and C1276/76 are for the front speed sensor LH.
* DTCs C1238/38 and C1277/77 are for the rear speed sensor RH.
* DTCs C1239/39 and C1278/78 are for the rear speed sensor LH.

WIRING DIAGRAM

Refer to DTCs C0200/31, C0205/32, C0210/33 and C0215/34 C0200 for front, and C0210 for rear).

INSPECTION PROCEDURE

NOTICE:
When replacing the skid control ECU, perform initialization and calibration of the linear solenoid valve Initialization.

HINT
When C0200/31, C0205/32, C0210/33, and/or C0215/34 are output together with C1235/35, C1236/36, C1238/38, and/or C1239/39, inspect and repair the trouble areas indicated by C0200/31, C0205/32, C0210/33, and/or C0215/34 first C0200 for front, or C0210 for rear).

PROCEDURE

1. CHECK SPEED SENSOR AND SPEED SENSOR ROTOR SERRATIONS

(a) Connect an oscilloscope to each speed sensor terminal of the skid control ECU and body ground.





(b) Check that 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.

(c) Check that the waveform does not change while jiggling a connector or a wire harness.

OK:

The waveform does not change.

Text in Illustration





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.

Result:





C -- CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE)

B -- CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - SPEED SENSOR)
A -- Continue to next step.

2. 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 20 km/h (12 mph) or more for at least 15 seconds.

(e) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result:





B -- REPLACE SKID CONTROL ECU Removal

A -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting

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

(a) Turn the power switch off.





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

(c) Disconnect the skid control ECU connectors and the speed sensor connectors.

(d) 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.

4. CHECK SPEED SENSOR AND SPEED SENSOR ROTOR

(a) Remove the speed sensor and speed sensor rotor Removal and Removal for front, or Removal and Removal for rear).

(b) Check the speed sensor tip and speed sensor rotor.

OK:

The sensor tip and rotor 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 SPEED SENSOR AND SPEED SENSOR ROTOR
OK -- Continue to next step.

5. RECONFIRM DTC

(a) Install the speed sensor and the speed sensor rotor.

(b) Reconnect the skid control ECU connectors and the speed sensor connectors.

(c) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(d) Turn the power switch on (READY).

(e) Drive the vehicle at a speed of 20 km/h (12 mph) or more for at least 15 seconds.

(f) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result:





B -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting
A -- Continue to next step.

6. REPLACE SPEED SENSOR

(a) Turn the power switch off.

(b) Replace the front speed sensor and the rear speed sensor Removal for front, or Removal for rear).

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

NEXT -- Continue to next step.

7. RECONFIRM DTC

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the power switch on (READY).

(c) Drive the vehicle at a speed of 20 km/h (12 mph) or more for at least 15 seconds.

(d) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result:





B -- END
A -- Continue to next step.

8. REPLACE SPEED SENSOR ROTOR

(a) Turn the power switch off.

(b) Remove the front drive shaft assembly (for front) Removal.

(c) Replace the front drive outboard joint shaft assembly (front speed sensor rotor) or the rear axle hub and bearing assembly (rear speed sensor rotor) Disassembly for front, or Removal for rear).

HINT
* If the front speed sensor rotor needs to be replaced, replace it together with the front drive outboard joint shaft assembly.
* The rear speed sensor rotor is incorporated into the rear axle hub and bearing assembly.
If the rear speed sensor rotor needs to be replaced, replace it together with the rear axle hub and bearing assembly.
NOTICE:
Check the speed sensor signal after replacement Test Mode Procedure.

NEXT -- Continue to next step.

9. RECONFIRM DTC

(a) Install the drive shaft assembly (for front).

(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 20 km/h (12 mph) or more for at least 15 seconds.

(e) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result:





B -- END

A -- REPLACE SKID CONTROL ECU Removal

10. CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE)

(a) Turn the power switch off.





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

(c) Disconnect the skid control sensor wire.

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

Standard Resistance:

for RH
for LH










Text in Illustration





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

NG -- REPLACE SKID CONTROL SENSOR WIRE Removal
OK -- Continue to next step.

11. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - 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.

(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.

12. RECONFIRM DTC

(a) Reconnect the skid control ECU connectors and the skid control sensor wire.

(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 20 km/h (12 mph) or more for at least 15 seconds.

(e) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result:





B -- CHECK FOR INTERMITTENT PROBLEMS How To Proceed With Troubleshooting
A -- Continue to next step.

13. REPLACE SPEED SENSOR AND SPEED SENSOR ROTOR

(a) Turn the power switch off.

(b) Replace the rear speed sensor and the rear axle hub and bearing assembly (rear speed sensor rotor) Removal.

HINT
The rear speed sensor rotor is incorporated into the rear axle hub and bearing assembly.

If the rear speed sensor rotor needs to be replaced, replace it together with the rear axle hub and bearing assembly with rear speed sensor.

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

NEXT -- Continue to next step.

14. RECONFIRM DTC

(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.

(b) Turn the power switch on (READY).

(c) Drive the vehicle at a speed of 20 km/h (12 mph) or more for at least 15 seconds.

(d) Check if the same DTC is recorded Reading and Clearing Diagnostic Trouble Codes.

Result:





B -- END

A -- REPLACE SKID CONTROL ECU Removal