VEHICLE STABILITY CONTROL SYSTEM(for TMC Made), Diagnostic DTC:C1273, C1274, C1403, C1404

DTC Code DTC Name
C1273 Low Output Signal of Rear Speed Sensor RH (Test Mode DTC)
C1274 Low Output Signal of Rear Speed Sensor LH (Test Mode DTC)
C1403 Rear Speed Sensor RH Malfunction
C1404 Rear Speed Sensor LH Malfunction

DESCRIPTION

The speed sensor detects wheel speed and sends the appropriate signals to the skid control ECU (brake actuator assembly). These signals are used for ABS control.

Speed sensor rotors have rows of alternating N and S magnetic poles, and their magnetic fields change when the rotors turn.

Each speed sensor detects that magnetic change and sends a pulse signal to the skid control ECU (brake actuator assembly).

Tech Tips

When the connectors between the speed sensor and skid control ECU are connected, the following waveform is output.

A01VGFEE02
Text in Illustration
*1 Speed Sensor *2 Speed Sensor Rotor
*a

Waveform (Reference):

Between Speed Sensor (-) and Body Ground

 *b Low speed
*c High speed - -
DTC No. DTC Detection Condition Trouble Area

C1403

C1404

Any of the following is detected:


  1. At a vehicle speed of 10 km/h (6 mph) or more, output voltage from one of the speed sensors is less than that from the other sensors for 15 seconds or more.

  2. At a vehicle speed less than 10 km/h (6 mph), output from one of the speed sensors is 0 km/h (0 mph) for 1 second or more.

  3. At a vehicle speed less than 10 km/h (6 mph), outputs from both speed sensors are 0 km/h (0 mph) for 15 seconds or more. (except both rear speed sensors are 0 km/h)

  • Rear speed sensor RH/LH

  • Speed sensor rotor
Test Mode Diagnosis Code
DTC No. DTC Detection Condition Trouble Area

C1273

C1274

 Detected only during Test Mode.

  • Rear speed sensor RH/LH

  • Speed sensor rotor

Tech Tips


  • DTC C1403 and C1273 are for the rear speed sensor RH.

  • DTC C1404 and C1274 are for the rear speed sensor LH.

WIRING DIAGRAM

A01VK6KE04

CAUTION / NOTICE / HINT

Note

Disassembly of the speed sensor from the rear axle hub and bearing assembly is prohibited.

PROCEDURE


  1. CHECK REAR SPEED SENSOR INSTALLATION


    1. Turn the ignition switch off.

    2. A01VI2SE02
      Text in Illustration
      *a Normal
      *b Abnormal
      *c Clearance

      Check the speed sensor installation.

      OK
      There is no clearance between the sensor and the rear axle hub.

      Tech Tips

      Because the rear axle hub and bearing assembly cannot be disassembled, if the rear speed sensor needs replacement, replace the rear axle hub and bearing assembly.


    NG

    REPLACE REAR AXLE HUB AND BEARING ASSEMBLY Click here

    OK

  2. READ VALUE USING INTELLIGENT TESTER (REAR SPEED SENSOR)


    1. Connect the intelligent tester to the DLC3.

    2. Start the engine.

    3. Enter the following menus: Chassis / ABS/VSC/TRC / Data List.

      ABS/VSC/TRC (Skid Control ECU)
      Tester Display Measurement Item/Range Normal Condition Diagnostic Note
      RR Wheel Speed RR wheel speed sensor reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph) Vehicle stopped: 0 km/h When driving at constant speed: No large fluctuations
      RL Wheel Speed RL wheel speed sensor reading / min.: 0 km/h (0 mph), max.: 326 km/h (202 mph) Vehicle stopped: 0 km/h When driving at constant speed: No large fluctuations

    4. Check that there is no difference between the speed value output from the speed sensor displayed on the intelligent tester and the speed value displayed on the speedometer when driving the vehicle.

      Tech Tips

      Factors that affect the indicated vehicle speed include tire size, tire inflation, and tire wear. The speed indicated on the speedometer has an allowable margin of error. This can be tested using a speedometer tester (calibrated chassis dynamometer). For details about testing and the margin of error, see the reference chart Click here.

      OK
      The speed value output from the speed sensor displayed on the intelligent tester is the same as the actual vehicle speed measured using a speedometer tester (calibrated chassis dynamometer).

      Note

      Check the speed sensor signal after replacement Click here.

      Tech Tips


      • 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.

      • If troubleshooting has been carried out according to the Problem Symptoms Table, refer back to the table and proceed to the next step Click here.


    OK

    END

    NG

    REPLACE REAR AXLE HUB AND BEARING ASSEMBLY Click here