Control Circuit Inspection

Check waveform
1. IG "OFF" and connect GDS.
2. Connect probe to COM terminal to check control waveform by using oscilloscope function.
3. ENG "ON" and monitor signal waveform.
  Specification: Compare actual waveform to those in appropriate figures .
  
  Fig 1: Checking Generator Signal Waveform
  Courtesy of HYUNDAI MOTOR AMERICA
4. Is the measured waveform within specification?
  YES
  - Go to " Check Open in harness" as follows.
  NO
  - Go to " Check Short in harness" as follows.
Check Open in harness
1. IG "OFF" and disconnect Alternator and ECM connector
2. Measure resistant between com terminal of alternator and ECM harness connector.
  Specification: Below 1Ω
  
  Fig 2: Measuring Resistance Between COM Terminal Of Alternator And ECM
  Courtesy of HYUNDAI MOTOR AMERICA
3. Is the measured resistance within specification?
  YES
  - Go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  NO
  - Repair open in harness and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check Short in harness
1. IG "OFF" and disconnect Alternator and ECM connector
2. Measure the resistance between com terminal of the alternator harness connector and chassis ground.
3. IG "ON" and measure the voltage between com terminal of the alternator harness connector and chassis ground.
  Specification: (2.) Approx. below 1Ω, (3.) Approx. 0V
  
  Fig 3: Measuring Voltage Between COM Terminal Of Alternator And Chassis Ground
  Courtesy of HYUNDAI MOTOR AMERICA
4. Is the measured resistance and voltage within specification?
  YES
  - Substitute with a known - good ECM and check for proper operation. If the problem is corrected, replace ECM and go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  NO
  - Repair short in harness and go to "VERIFICATION OF VEHICLE REPAIR " procedure.