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 C1464/31, C1465/32, C1466/33 and C1467/34 C1271 for front, and C1273 for rear).
INSPECTION PROCEDURE
NOTICE:
When replacing the brake booster with master cylinder (skid control ECU), perform initialization and calibration of the linear solenoid valve Initialization.
PROCEDURE
1. CHECK DTC
(a) Check that no speed sensor malfunction DTC is output Reading and Clearing Diagnostic Trouble Codes.
HINT
When C1464/31, C1465/32, C1466/33, and/or C1467/34 are output together with C1235/35, C1236/36, C1238/38, and/or C1239/39, inspect and repair the trouble areas indicated by C1464/31, C1465/32, C1466/33, and/or C1467/34 first.
Result:
B -- CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE)
C -- REPAIR CIRCUITS INDICATED BY OUTPUT DTCS Electronically Controlled Brake System
A -- Continue to next step.
2. CHECK FRONT SPEED SENSOR AND FRONT SPEED SENSOR ROTOR
(a) Remove the front speed sensor and front speed sensor rotor Removal and Removal).
(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:
* If no damage to the speed sensor tip is found during this inspection, do not replace the speed sensor.
If there are any ferrous metal filings stuck to the rotor, this will result in a malfunction, so confirm that the rotor is not contaminated with foreign matter before replacing the sensor.
* Check the speed sensor signal after cleaning or replacement Test Mode Procedure.
NG -- CLEAN OR REPLACE FRONT SPEED SENSOR AND FRONT SPEED SENSOR ROTOR
OK -- Continue to next step.
3. CHECK HARNESS AND CONNECTOR (SKID CONTROL ECU - FRONT SPEED SENSOR)
(a) Install the front speed sensor and front speed sensor rotor.
(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 connector and the front speed sensor connector.
(d) 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.
4. INSPECT SKID CONTROL ECU (SENSOR OUTPUT)
(a) Reconnect the skid control ECU connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
for RH
for LH
Text in Illustration
NG -- REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Removal
OK -- Continue to next step.
5. RECONFIRM DTC
(a) Turn the power switch off.
(b) Reconnect the front speed sensor connector.
(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 FRONT SPEED SENSOR
(a) Turn the power 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.
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 FRONT SPEED SENSOR ROTOR
(a) Turn the power switch off.
(b) Replace the front axle hub sub-assembly (front speed sensor rotor) Removal.
HINT
The front speed sensor rotor is incorporated into the front axle hub sub-assembly.
If the front 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.
9. 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 BRAKE BOOSTER WITH MASTER CYLINDER Removal
10. CHECK HARNESS AND CONNECTOR (SKID CONTROL SENSOR WIRE)
(a) Make sure that there is no looseness at the locking part and the connecting part of the connectors.
(b) Disconnect the rear speed sensor connector and the skid control sensor wire.
(c) 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 - SKID CONTROL SENSOR WIRE)
(a) Make sure that there is no looseness at the locking part and the 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.
12. INSPECT SKID CONTROL ECU (SENSOR OUTPUT)
(a) Reconnect the skid control ECU connector.
(b) Turn the power switch on (IG).
(c) Measure the voltage according to the value(s) in the table below.
Standard Voltage:
for RH
for LH
Text in Illustration
NG -- REPLACE BRAKE BOOSTER WITH MASTER CYLINDER Removal
OK -- Continue to next step.
13. RECONFIRM DTC
(a) Turn the power switch off.
(b) Reconnect the rear speed sensor connector and the skid control sensor wire.
(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.
14. REPLACE REAR SPEED SENSOR AND REAR 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.
15. 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 BRAKE BOOSTER WITH MASTER CYLINDER Removal