Anti-Lock Brake System

BRAKE CONTROL: ANTI-LOCK 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

The Skid Control ECU sets this DTC if, according to abnormal signals input by the sensor, it detects that foreign material is adhering to the speed sensor tip or the sensor rotor, or the rotor has any missing teeth.

This DTC may be set if parts such as the speed sensor circuit connector or wire harness are malfunctioning.





HINT
DTC C1235/35 relates to the front speed sensor RH.

DTC C1236/36 relates to the front speed sensor LH.

DTC C1238/38 relates to the rear speed sensor RH.

DTC C1239/39 relates to the rear speed sensor LH.

WIRING DIAGRAM





INSPECTION PROCEDURE

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

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

PROCEDURE

1. INSPECT EACH SPEED SENSOR

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





(b) Disconnect each speed sensor connector.

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

Standard Resistance:

for Front RH Side
for Front RH Side
for Rear RH Side
for Rear LH Side


















Text in Illustration





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

NEXT -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (SPEED SENSOR WIRE)

(a) Disconnect the speed sensor wire.

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





Standard Resistance:

for Front RH Side
for Front LH Side
for Rear RH Side
for Rear LH Side


















Text in Illustration





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

NEXT -- Continue to next step.

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

(a) Disconnect the skid control ECU connector.

(b) Disconnect speed sensor connectors.

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

Standard Resistance:

for Front RH Side
for Front LH Side
for Rear RH Side
for Rear LH Side


















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

4. INSPECT SKID CONTROL ECU (SENSOR INPUT)

(a) Disconnect the speed sensor connectors.





(b) Turn the ignition switch to ON.

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

Standard Voltage:





Text in Illustration





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

5. RECONFIRM DTC

(a) Clear the DTCs ABS (Antilock Brake System).

(b) Drive the vehicle at 10 km/h (6 mph) or more to activate initial check.

(c) Check if the same DTC is recorded ABS (Antilock Brake System).

Result





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

6. CHECK SPEED SENSOR TIP

(a) Turn the ignition switch off.

(b) Remove the speed sensor.

Front speed sensor Removal.

Rear speed sensor Removal.

(c) Check the speed sensor tip.

OK:

No scratches or foreign matter on the sensor tip.

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

NG -- CLEAN OR REPLACE SPEED SENSOR
OK -- Continue to next step.

7. CHECK SPEED SENSOR ROTOR

(a) Check the speed sensor rotors.

HINT
* The front speed sensor rotor is incorporated into the front axle hub bearing.
* The rear speed sensor rotor is incorporated into the rear axle hub bearing.

OK:

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

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

NG -- CLEAN OR REPLACE SPEED SENSOR ROTOR
OK -- Continue to next step.

8. REPLACE SPEED SENSOR

(a) Turn the ignition switch off.

(b) Replace speed sensor.

Front speed sensor Removal.

Rear speed sensor Removal.

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

NEXT -- Continue to next step.

9. RECONFIRM DTC

(a) Clear the DTC ABS (Antilock Brake System).

(b) Start the engine.

(c) Drive the vehicle at a speed of 10 km/h (6 mph) or more to activate initial check.

(d) Check if the same DTC is recorded ABS (Antilock Brake System).

Result





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

10. REPLACE SPEED SENSOR ROTOR

(a) Turn the ignition switch off.

(b) Replace the axle hub bearing.

Front speed sensor Removal.

Rear speed sensor Disassembly.

HINT
* The front speed sensor rotor is incorporated into the front axle hub bearing.
* The rear speed sensor rotor is incorporated into the rear axle hub bearing.

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

NEXT -- Continue to next step.

11. RECONFIRM DTC

(a) Clear the DTC ABS (Antilock Brake System).

(b) Start the engine.

(c) Drive the vehicle at a speed of 10 km/h (6 mph) or more to activate initial check.

(d) Check if the same DTC is recorded ABS (Antilock Brake System).

Result





B -- END

A -- REPLACE BRAKE ACTUATOR ASSEMBLY Removal