Toyota Celica, Corolla, ECHO & MR2 1999-05

Wheel Speed Sensors

Print

The speed of each wheel is monitored by a sensor. A toothed wheel (sensor rotor) rotates in front of the sensor, generating a small AC voltage which is transmitted to the ABS controller. The ABS computer compares the signals and reacts to rapid loss of wheel speed at a particular wheel by engaging the ABS system. Each speed sensor is individually removable. In most cases, the toothed wheels may be replaced if damaged, but disassembly of other components such as hub and knuckle, constant velocity joints or axles may be required.

Removal & Installation



  1. The right side and the left side procedures are the same.
  2.  
  3. Remove the wheel.
  4.  
  5. Remove the fender liner.
  6.  
  7. Disengage the speed sensor wire harness clamp from the body.
  8.  
  9. Disconnect the speed sensor connector.
  10.  
  11. Remove the 2 clamp bolts holding the sensor harness from the body and shock absorber.
  12.  
  13. Remove the bolt and speed sensor.
    CAUTION
    Keep the tip of the sensor clean.

  14.  

To install:

Click image to see an enlarged view

Fig. Removal and installation of the speed sensor

  1. Install the speed sensor with the bolt. Torque to 71 in. lbs. (8 Nm) of torque.
  2.  
  3. Install the sensor harness clamp with the 2 bolts to the body and shock absorber.
  4.  
  5. Connect the speed sensor connector.
  6.  
  7. Engage the speed sensor wire harness clamp to the body.
  8.  
  9. Install the fender liner.
  10.  
  11. Install the wheel.
  12.  

Front
  1. Remove the fender shield.
  2.  



Click image to see an enlarged view

Fig. The front speed sensors are located around the strut assembly

  1. Disconnect the speed sensor wiring.
  2.  
  3. Remove the three clamp bolts holding the sensor harness from the body and shock absorber.
  4.  



Click image to see an enlarged view

Fig. Only three bolts retain the sensor harness to the body and strut

  1. Remove the speed sensor retaining bolt from the steering knuckle.
  2.  
  3. Remove the clamp from the speed sensor.
  4.  

To install:

  1. Install the sensor to the steering knuckle and tighten the bolt to 71 inch lbs. (8 Nm).
  2.  

Make sure that there are no foreign objects on the sensor or the part of the knuckle where it seats. The sensor should be seated flat against the knuckle when you tighten the bolt.

  1. Install the clamp to the shock bracket until a clicking is heard.
  2.  
  3. Install the sensor harness with the three bolts.
  4.  
  5. Connect the wiring to the sensor.
  6.  
  7. Perform the speed sensor signal check.
  8.  

Rear


Click image to see an enlarged view

Fig. Rear speed sensor harness routing

  1. On liftback models, remove the rear seat back and deck trim panel.
  2.  
  3. On coupes, remove the luggage compartment trim cover.
  4.  



Click image to see an enlarged view

Fig. Rear speed sensor wiring connector mounting

  1. Disconnect the wiring and pull out the sensor wire with grommet.
  2.  
  3. Remove the two clamp bolts holding the sensor wire harness from the body and the shock.
  4.  



Click image to see an enlarged view

Fig. Unbolt the two clamp bolts for the rear speed sensor

  1. Remove the speed sensor from the axle carrier.
  2.  

To install:

  1. Install the sensor and tighten the bolt to 71 inch lbs. (8 Nm).
  2.  

Make sure that there are no foreign objects on the sensor or the part of the knuckle where it seats. The sensor should be seated flat against the knuckle when you tighten the bolt.

  1. Feed the harness connector back inside the vehicle and connect.
  2.  
  3. On the liftbacks, install the deck trim side panel and rear seat back.
  4.  
  5. On coupes, install the luggage compartment trim cover.
  6.  
  7. Install the grommet securely.
  8.  
  9. Attach the sensor harness with the two clamps and bolts.
  10.  
  11. Perform the speed sensor signal check.
  12.  

Testing



  1. To perform the speed sensor signal check, turn the ignition switch to the OFF position.
  2.  
  3. Using a jumper wire, connect terminals Ts and E1 of the DLC1.
  4.  
  5. Start the engine.
  6.  
  7. Check that the ABS warning light blinks.
  8.  

If the light does not blink, inspect the ABS wring light circuit.

  1. Drive the vehicle straight forward at 28 mph (45 km) for a short distance (several seconds).
  2.  
  3. Stop the vehicle.
  4.  
  5. Using another jumper wire, connect terminals Ts and E1 of the DLC1.
  6.  
  7. Read the number of blinks of the ABS warning light. If every second is normal, a normal code will be output.
  8.  

A cycle of 0.25 seconds ON and 0.25 seconds OFF is repeated. If two or more malfunctions are indicated at the same time, the lowest numbered code will be displayed first.

  1. After performing the check, disconnect the two jumper wires from the DLC1 and turn the ignition switch OFF .
  2.  

 
label.common.footer.alt.autozoneLogo