4E
DTC C1021, C1022 / C1025, C1026 / C1031, C1032 / C1035, C1036 (No.21, 22 / 25, 26 / 31, 32 / 35, 36): Right-Front / Left-Front / Right-Rear / Left-Rear Wheel Speed Sensor Circuit
Wiring Diagram
[A]: ABS hydraulic unit / control module connector E142 (viewed from control module side) 3. Left front wheel speed sensor 6. Right rear wheel speed sensor.
1. Battery 4. Right front wheel speed sensor. 7. ABS hydraulic unit / control module connector of harness
2. Main fuse box 5. Left rear wheel speed sensor.      
Circuit Description
The ABS control module monitors the voltage at the positive (+) terminal of each sensor while the ignition switch is ON. When the voltage is not within the specified range, an applicable DTC will be set. Also, when the ABS control module detects a sensor which outputs an abnormal signal while comparing signals from wheel speed sensors, an applicable DTC will be set.
NOTE:
When the vehicle was operated in any of the following ways, one of these DTC’s may be set even when the sensor is in good condition. If such possibility is suspected, repair the trouble (dragging of brake, etc.) of the vehicle, clear DTC once and then after performing the driving test as described in Step 2 of ABS Check , check whether or not any abnormality exists.
• The vehicle was driven with parking brake pulled.
• The vehicle was driven with brake dragging.
• Wheel spin occurred while driving.
• Wheel(s) was turned while the vehicle was jacked up.
• The vehicle was stuck.
Troubleshooting
Step Action YES NO
1
Was ABS Check performed?
Go to Step 2.
Go to ABS Check .
2
1) Turn ignition switch to OFF position.
2) Disconnect applicable ABS wheel speed sensor coupler.
3) Measure resistance between terminals of ABS wheel speed sensor. Refer Front Wheel Speed Sensor Inspection and Rear Wheel Speed Sensor Inspection .
Is measured resistance values as specified?
Go to Step 3.
Replace ABS wheel speed sensor assembly.
3
1) Connect ABS wheel speed sensor coupler.
2) Disconnect ABS hydraulic unit / control module connector.
3) Check for proper connection to ABS hydraulic unit / control module at each sensor terminal.
4) If OK, then turn ignition switch ON and measure voltage between sensor terminal of module connector and vehicle body ground.
Is it 0 V?
Go to Step 4.
ABS wheel speed sensor circuit shorted to power.
4
1) Turn ignition switch to OFF position.
2) Measure resistance between the following points.
• Both ABS hydraulic unit / control module connector terminals of the corresponding sensor.
This check result should be the same as Step 2.
• Either terminal of wheel speed sensor coupler and vehicle body ground.
This check result should be no continuity.
Are both check results OK?
Go to Step 5.
Circuit open or shorted to ground.
5
1) Remove applicable ABS wheel speed sensor.
2) Check sensor for damage or foreign material attached.
Is it in good condition?
Go to Step 4.
Clean repair, or replace.
6
Check front and/or rear sensor ring for the following (remove rear axle shaft as necessary):
• Rotor serration (teeth) neither missing or damaged.
• No foreign material being attached.
• Rotor not being eccentric.
• Wheel bearing free from excessive play.
Are they in good condition?
Go to Step 7.
Clean, repair or replace.
7
1) Install ABS wheel speed sensor and check that there is no clearance between sensor and knuckle.
Refer to Front Wheel Speed Sensor Inspection and/or Rear Wheel Speed Sensor Inspection .
Is it OK?
Go to Step 8.
Replace ABS wheel speed sensor.
8
1) Referring to “Reference” in Front Wheel Speed Sensor On-Vehicle Inspection and/or “Reference” in Rear Wheel Speed Sensor On-Vehicle Inspection . Check output voltage or waveform.
Is specified voltage and/or waveform obtained?
Substitute a known-good ABS hydraulic unit / control module assembly and recheck.
Replace sensor and recheck.