Signal Circuit Inspection

■ Wheel Speed Sensor Circuit Check 

1. Lift the vehicle with suitable lift.
2. IG "ON" and place gear in neutral position.
3. Turn the wheel by hand.
4. Measure waveform between wheel speed sensor signal terminal of the HECU harness connector and chassis ground in the oscilloscope with GDS using VMI.

   Specification:  High: Approx. 1.4V, Low: Approx. 0.7V

5. Is the measured waveform within specifications?

   YES 

   • Substitute with a known-good HECU and check for proper operation. If problem is corrected, replace HECU and then go to "Verification Of Vehicle Repair " procedure.
   NOTE: ** In case of replacing HECU, perform following procedures.
   

   1. "ASP Calibration" for steering angle sensor offset correction (refer to C1261 )
   2. "Longitudinal Sensor Calibration" for Longitudinal sensor offset correction (refer to C1285 )
   3. "Variant Coding" (refer to C1702 )

   NO 

   • Repair open or short in signal circuit between HECU harness connector and wheel speed sensor harness connector, and then go to "Verification Of Vehicle Repair " procedure.
   • If there is no problem in signal circuit, substitute with a known-good Wheel speed sensor and check for proper operation. If problem is corrected, replace Wheel speed sensor and then go to "Verification Of Vehicle Repair " procedure.