3.
Has a problem been found?
 | ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure. |
 | ▶ Go to "Power Circuit Inspection" procedure. |
Many malfunctions in the electrical system are caused by poor harness(es) and terminal condition. Faults can also be caused by interference from other electrical systems, and mechanical or chemical damage.
Thoroughly check connectors for looseness, poor connection, bending, corrosion, contamination, deterioration, or damage.
Has a problem been found?
| ▶ Repair as necessary and then go to "Verification of Vehicle Repair" procedure. |
| ▶ Go to "Power Circuit Inspection" procedure. |
Ignition "ON" & Engine "OFF".
Measure voltage between power terminal of the wheel speed sensor harness connector and chassis ground.
Specification : Approx. B+
Is the measured value within specifications?
| ▶ Go to "Signal Circuit Inspection" procedure. |
| ▶ Repair open or short in power circuit between HECU harness connector and wheel speed sensorharness connector and then go to "Verification of vehicle Repair" procedure. If there is no problem in Power circuit, 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. |
Lift the vehicle.
Ignition "ON" & Engine "OFF".
Turn the wheel by hand.
Measure waveform between signal terminal of the wheel speed sensor harness connector and chassis ground with osciloscope.
Specification : High : 1.18~1.68V , Low : 0.59~0.84V
Is the measured waveform within specifications?
| ▶ 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. |
| ▶ 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, go to "Component Inspection" procedure. |
