C1278
BRAKE CONTROL: VEHICLE STABILITY CONTROL SYSTEM: C0210/33: Right Rear Wheel Speed Sensor Signal Malfunction
DTC C0210/33 - Right Rear Wheel Speed Sensor Signal Malfunction
DTC C0215/34 - Left Rear Wheel Speed Sensor Signal
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 C1273/73 - Low Output Signal of Rear Speed Sensor RH (Test Mode DTC)
DTC C1274/74 - Low Output Signal of Rear 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 transmits the appropriate signals to the skid control ECU. These signals are used for control of the ABS system. Each of the front and rear rotors has 48 serrations.
When the rotors rotate, the magnetic field generated by the permanent magnet in the speed sensor induces AC voltage. Since the frequency of this AC voltage changes in direct proportion to the speed of the rotor, the frequency is used by the skid control ECU to detect the speed of each wheel.
DTCs C1273/73, C1274/74 C1277/77, and C1278/78 are output only in the test mode (SIGNAL CHECK).
HINT:
DTC C0210/33 and C1238/38 are for the right rear speed sensor.
DTC C0215/34 and C1239/39 are for the left rear speed sensor.
WIRING DIAGRAM
INSPECTION PROCEDURE
NOTE: When replacing the ABS & TRACTION actuator assembly , perform zero point calibration Programming and Relearning.
HINT: Start the inspection from step 1 when using Techstream and start from step 3 when not using Techstream.
PROCEDURE
1. CHECK HARNESS AND CONNECTOR (MOMENTARY INTERRUPTION)
(a) Using Techstream, check for any momentary interruption in the wire harness and connector corresponding to a DTC Check for Intermittent Problems.
DATA LIST: ABS / VSC / TRAC
OK:
There are no momentary interruptions.
HINT: Perform the above inspection before removing the sensor and connector.
NG -- CHECK AND REPAIR HARNESS AND CONNECTOR (SPEED SENSOR CIRCUIT)
OK -- Continue to next step.
2. READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)
(a) Connect Techstream to the DLC3.
(b) Start the engine.
(c) Select "DATA LIST" and read the value displayed on Techstream.
DATA LIST: ABS / VSC / TRAC
(d) Check that there is no difference between the speed value output from the speed sensor displayed on Techstream and the speed value displayed on the speedometer when driving the vehicle.
OK:
The speed value output from the speed sensor displayed on Techstream is the same as the actual vehicle speed.
NG -- INSPECT REAR SPEED SENSOR INSTALLATION
OK -- Continue to next step.
3. PERFORM TEST MODE (SIGNAL CHECK)
(a) Check if test mode (signal check) DTCs are detected.
Result:
B -- INSPECT REAR SPEED SENSOR INSTALLATION
A -- Continue to next step.
4. INSPECT SPEED SENSOR AND SENSOR ROTOR SERRATIONS
(a) INSPECTION USING OSCILLOSCOPE
(1) Disconnect the rear speed sensor connector.
(2) Connect the oscilloscope to terminals 1 and 2 of the rear speed sensor.
(3) Check that a waveform is output when the tires are rotated.
OK:
A waveform as shown in the figure should be output.
HINT:
- As vehicle speed (wheel rotation speed) increases, the width of the waveform narrows and the fluctuation in the output voltage becomes greater.
- When noise is identified in the waveform on the oscilloscope, error signals are generated due to rotor scratches, looseness or foreign matter attached to the speed sensor.
NG -- CLEAN OR REPLACE SPEED SENSOR AND SENSOR ROTOR
OK -- Continue to next step.
5. RECONFIRM DTC
(a) Clear the DTC.
(b) Start the engine.
(c) Drive the vehicle at the speed of 20 mph (32 km/h) or more for 60 seconds or more.
(d) Check that the same DTC is recorded.
Result:
HINT:
- These DTCs may be stored due to a malfunction in the connector terminal connection, etc.
- If troubleshooting has been carried out according to the PROBLEM SYMPTOMS TABLE, refer back to the table and proceed to the next step Problem Symptoms Table.
B -- INSPECT REAR SPEED SENSOR INSTALLATION
A -- END
6. INSPECT REAR SPEED SENSOR INSTALLATION
(a) Check the rear speed sensor installation.
OK:
There is no clearance between the sensor and rear axle carrier.
NOTE: Check the speed sensor signal after replacement Test Mode Procedure.
NG -- INSTALL REAR SPEED SENSOR CORRECTLY OR REPLACE REAR SPEED SENSOR
OK -- Continue to next step.
7. INSPECT REAR SPEED SENSOR
(a) Disconnect the rear speed sensor connector.
(b) Measure the resistance according to the value(s) in the table below.
Resistance:
LH
RH
NOTE: Check the speed sensor signal after replacement Test Mode Procedure.
NG -- REPLACE REAR SPEED SENSOR
OK -- Continue to next step.
8. CHECK HARNESS AND CONNECTOR (REAR SPEED SENSOR TO SKID CONTROL ECU)
(a) SKID CONTROL ECU TO SKID CONTROL SENSOR WIRE
(1) Disconnect the skid control ECU connector and the rear speed sensor connector.
(2) Disconnect the skid control sensor wire.
(3) Measure the resistance according to the value(s) in the table below.
Resistance:
LH
RH
NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR (SKID CONTROL ECU TO SKID CONTROL SENSOR WIRE)
OK -- Continue to next step.
9. CHECK SKID CONTROL SENSOR WIRE
(a) SKID CONTROL SENSOR WIRE
(1) Measure the resistance according to the value(s) in the table below.
Resistance:
LH
RH
NG -- REPAIR OR REPLACE SKID CONTROL SENSOR WIRE
OK -- Continue to next step.
10. INSPECT SPEED SENSOR AND SENSOR ROTOR SERRATIONS
(a) INSPECTION USING OSCILLOSCOPE
(1) Disconnect the rear speed sensor connector.
(2) Connect the oscilloscope to terminals 1 and 2 of the rear speed sensor.
(3) Check that a waveform is output when the tires are rotated.
OK:
A waveforms as shown in the figure should be output.
HINT:
- As vehicle speed (wheel rotation speed) increases, the width of the waveform narrows and the fluctuation in the output voltage becomes greater.
- When noise is identified in the waveform on the oscilloscope, error signals are generated due to rotor scratches, looseness or foreign matter attached to the speed sensor.
NG -- CLEAN OR REPLACE SPEED SENSOR AND SENSOR ROTOR
OK -- Continue to next step.
11. READ VALUE USING TECHSTREAM (REAR SPEED SENSOR)
(a) Connect Techstream to the DLC3.
(b) Start the engine.
(c) Select "DATA LIST" and read the value displayed on Techstream.
DATA LIST: ABS / VSC / TRAC
(d) Check that there is no difference between the speed value output from the speed sensor displayed on Techstream and the speed value displayed on the speedometer when driving the vehicle.
OK:
The speed value output from the speed sensor displayed on Techstream is the same as the actual vehicle speed.
HINT: These DTCs may be stored due to a malfunction in the connector terminal connection, etc.
NG -- REPLACE ABS & TRACTION ACTUATOR ASSEMBLY
OK -- END