Component Inspection

ABS VEHICLE 

1. ENG "ON".
2. Measure signal waveform of Vehicle Speed from ABS to ECM/PCM while driving.

   SPECIFICATION: 

   Fig 1: Vehicle Speed Sensor Signal Waveform Graph

   Courtesy of HYUNDAI MOTOR CO.
3. Is the signal waveform normal?

   YES  : --> Substitute with a known - good ECM/PCM and check for proper operation. If the problem is corrected, replace ECM/PCM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO  : --> Substitute with a known-good ABS control unit and check for proper operation. If the problem is corrected, replace ABS control unit and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

NON-ABS VEHICLE 

1. Engine "ON".
2. Measure signal waveform of wheel speed sensor while driving.

   SPECIFICATION: 

   Fig 1: Vehicle Speed Sensor Signal Waveform Graph

   Courtesy of HYUNDAI MOTOR CO.
3. Is the signal waveform normal?

   YES  : --> Substitute with a known - good ECM/PCM and check for proper operation. If the problem is corrected, replace ECM/PCM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.

   NO  : --> Substitute with a known - good wheel speed sensor and check for proper operation. If the problem is corrected, replace wheel speed sensor and go to "VERIFICATION OF VEHICLE REPAIR " procedure.