Foreign Object is Attached on Tip of Front Speed Sensor RH - Electronically Controlled Brake System
BRAKE CONTROL: ELECTRONICALLY CONTROLLED BRAKE SYSTEM: C1235/35: Foreign Object is Attached on Tip of Front Speed Sensor RH
DTC C1235/35 - Foreign Object is Attached on Tip of Front Speed Sensor RH
DTC C1236/36 - Foreign Object is Attached on Tip of Front Speed Sensor LH
DTC C1238/38 - Foreign Object is Attached on Tip of Rear Speed Sensor RH
DTC C1239/39 - Foreign Object is Attached on Tip of Rear Speed Sensor LH
DTC C1275/75 - Abnormal Change in Output Signal of Front Speed Sensor RH (Test Mode DTC)
DTC C1276/76 - Abnormal Change in Output Signal of Front Speed Sensor LH (Test Mode DTC)
DTC C1277/77 - Abnormal Change in Output Signal of Rear Speed Sensor RH (Test Mode DTC)
DTC C1278/78 - Abnormal Change in Output Signal of Rear 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.
Speed sensor rotors have 48 serrations. The hall IC type speed sensor use the frequency of output pulses to detect the vehicle speed. Because the sensor outputs digital pulses, it can detect vehicle speeds even when the vehicle is nearly stationary.
When foreign matter adheres to the speed sensor tip or speed sensor rotor, or the rotor teeth are chipped, 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 deleted 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
INSPECTION PROCEDURE
NOTE: 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 the oscilloscope to each speed sensor terminal of the skid control ECU.
(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.
HINT:
- As the vehicle speed (wheel revolution speed) increases, a cycle of the waveform narrows and the output voltage becomes greater.
- 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.
NG -- INSPECT SPEED SENSOR
OK -- Continue to next step.
2. RECONFIRM DTC
(a) Turn the power switch off.
(b) Clear the DTCs.
(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 60 seconds.
(e) Check if the same DTC is recorded.
Result:
B -- REPLACE SKID CONTROL ECU
A -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)
3. INSPECT 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 each speed sensor connector.
(d) Measure the resistance according to the value(s) in the table below.
Standard resistance:
for RH
for LH
NOTE: Check the speed sensor signal after replacement. Test Mode Procedure
NG -- REPLACE SPEED SENSOR
OK -- Continue to next step.
4. 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
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
5. RECONFIRM DTC
(a) Reconnect the skid control ECU connectors and the speed sensor connector.
(b) Clear the DTCs.
(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 60 seconds.
(e) Check if the same DTC is recorded.
Result:
B -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)
A -- Continue to next step.
6. CHECK SPEED SENSOR TIP
(a) Turn the power switch off.
(b) Remove the front or rear speed sensor.
(c) Check the speed sensor tip.
OK:
The sensor tip is free of scratches, oil, and foreign matter.
NOTE: 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) Remove the front or rear speed sensor.
(b) Check the speed sensor rotor.
OK:
The rotor is free of scratches, oil, missing teeth, and foreign matter.
NOTE: 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.
- If the rear speed sensor rotor needs to be replaced, replace it together with the outboard joint shaft assembly.
NG -- CLEAN OR REPLACE SPEED SENSOR ROTOR
OK -- Continue to next step.
8. RECONFIRM DTC
(a) Install the speed sensor and the speed sensor rotor.
(b) Clear the DTCs.
(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 60 seconds.
(e) Check if the same DTC is recorded.
Result:
B -- CHECK FOR INTERMITTENT PROBLEMS (SYMPTOM SIMULATION)
A -- Continue to next step.
9. REPLACE SPEED SENSOR
(a) Turn the power switch off.
(b) Replace the front speed sensor or the rear speed sensor.
NOTE: Check the speed sensor signal after replacement. Test Mode Procedure
NEXT -- Continue to next step.
10. RECONFIRM DTC
(a) Clear the DTCs.
(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 60 seconds.
(d) Check if the same DTC is recorded.
Result:
B -- END
A -- Continue to next step.
11. REPLACE SPEED SENSOR ROTOR
(a) Turn the power switch off.
(b) Remove the front drive shaft assembly or the rear drive shaft assembly.
(c) Replace the front drive outboard joint shaft assembly (front speed sensor rotor) or the outboard joint shaft assembly (rear speed sensor rotor).
HINT:
- If the front speed sensor rotor needs to be replaced, replace it together with the front drive outboard joint shaft assembly.
- If the rear speed sensor rotor needs to be replaced, replace it together with the outboard joint shaft assembly.
NOTE: Check the speed sensor signal after replacement. Test Mode Procedure
NEXT -- Continue to next step.
12. RECONFIRM DTC
(a) Install the drive shaft assembly.
(b) Clear the DTCs.
(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 60 seconds.
(e) Check if the same DTC is recorded.
Result:
B -- END
A -- REPLACE SKID CONTROL ECU