C1274 Low Output Signal of Rear Speed Sensor LH (Test Mode DTC)

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Diag Code: 74

CIRCUIT EXPLANATION
The speed sensors detect wheel speed and transmit the signals to the ECU. These signals are used for control of the ABS control 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 an 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 ECU to detect the speed of each wheel. DTCs C1273 and C1274 can be deleted when the speed sensor sends a wheel speed signal or the Test Mode ends. DTCs C1273 and C1274 are output only in the Test Mode.




DTC Code Diag Code DTC Detection Condition Trouble Area
C0210
C0215

33
34

When any of the following is detected:
  1. At a vehicle speed of 10 km/h (6 mph) or more, an open or short in the sensor signal circuit continues for 15 seconds or more.
  2. Momentary interruption of the sensor signal from the
    abnormal wheel occurs 7 times or more.
  3. An open in the speed sensor signal circuit continues for 0.5 seconds or more.
• Rear speed sensor RH/LH
• Speed sensor circuit
• Speed sensor rotor
• Sensor installation
• Skid control ECU
C1273
C1274

73
74

Detected only during Test Mode. • Rear speed sensor RH/LH
• Sensor installation
• Speed sensor rotor

• DTCs C0210 and C1273 are for the rear speed sensor RH.
• DTCs C0215 and C1274 are for the rear speed sensor LH.


WIRING DIAGRAM



INSPECTION PROCEDURE

1.PERFORM TEST MODE (SIGNAL CHECK)

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2.RECONFIRM DTC

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3.CHECK REAR SPEED SENSOR INSTALLATION

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4.CHECK REAR SPEED SENSOR TIP

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5.INSPECT REAR SPEED SENSOR

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

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7.CHECK SPEED SENSOR AND SPEED SENSOR ROTOR SERRATIONS

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8.RECONFIRM DTC

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9.DTC Clear

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