Signal Circuit Inspection

Check for open in harness
1. Ignition "OFF"
2. Disconnect VSS sensor connector.
3. Ignition "ON" & Engine "OFF"
4. Measure voltage between terminal 2 of sensor harness connector and chassis ground.
  Specification approximately 5V
  
  Fig 1: Measuring Voltage Between Terminal 2 Of Sensor Harness Connector And Chassis Ground
  Courtesy of HYUNDAI MOTOR CO.
5. Is measure voltage within Specification?
  YES
  - Go to "Check for short to ground in harness" below.
  NO
  - Open or short circuit between VSS harness connector and PCM harness connector.
  - Faulty PCM
  - Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.
  NOTE:
  1. In case, when the connector of VSS is disconnected, the voltage of terminal 2 is 0V.
    
    Possible cause: If the terminal 2 voltage of VSS is 0V, the possible cause is likely to be open or bad PCM.
  2. The voltage of terminal 2 is about 6.5~7.5V when the VSS connector is disconnected.
Check for short to ground in harness
When the voltage of VSS terminal 2 is 0V, the inspection of short circuit is recommended to find open or short circuit of signal line.
1. Ignition "OFF"
2. Disconnect VSS sensor connector and PCM connector.
3. Ignition "ON" & Engine "OFF"
4. Measure resistance between terminal 1 and 2 of sensor harness connector.
  Specification: infinite
  
  Fig 2: Measuring Resistance Between Terminal 1 And 2 Of Sensor Harness Connector
  Courtesy of HYUNDAI MOTOR CO.
5. Is measure resistance within Specification?
  YES
  - Go to "GROUND CIRCUIT INSPECTION " procedure.
  NO
  - Short circuit to chassis ground between VSS harness connector and PCM harness connector.
  - Short circuit between VSS signal circuit and ground circuit.
  - Repair as necessary and then go to "VERIFICATION OF VEHICLE REPAIR " procedure.