Signal Circuit Inspection

Check for short to ground in harness
1. Ignition "OFF"
2. Disconnect knock sensor connector.
3. Measure resistance between terminal 1 of knock sensor harness connector and chassis ground.
  Specification: Infinite
  
  Fig 1: Measuring Resistance Between Terminal 1 Of Knock Sensor Harness Connector And Chassis Ground
  Courtesy of KIA MOTORS AMERICA, INC.
4. Is the measured resistance within specifications?
  YES
  - Go to "Check for short to battery in harness" as below.
  NO
  - Check short to ground in signal harness.
  - Repair or replace as necessary and then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check for short to battery in harness
1. Ignition "OFF"
2. Disconnect knock sensor connector.
3. Ignition "ON" & Engine "OFF"
4. Measure voltage between terminal 1 of knock sensor harness connector and chassis ground.
  Specification: Approx. 0V
  
  Fig 2: Measuring Voltage Between Terminal 1 Of Knock Sensor Harness Connector And Chassis Ground
  Courtesy of KIA MOTORS AMERICA, INC.
5. Is the measured voltage within specifications?
  YES
  - Go to "Check for open in harness" as below.
  NO
  - Check for short to battery in harness.
  - Repair or replace as necessary and then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.
Check for open in harness
1. Ignition "OFF"
2. Disconnect knock sensor connector and PCM connector.
3. Measure resistance between terminal 1 of knock sensor harness connector and terminal C20 of PCM harness connector.
  Specification: Approx. below 1Ω
  
  Fig 3: Measuring Resistance Between Terminal 1 Of Knock Sensor Harness Connector And Terminal C20 Of PCM Harness Connector
  Courtesy of KIA MOTORS AMERICA, INC.
4. Is the measured resistance within specifications?
  YES
  - Go to "GROUND CIRCUIT INSPECTION " procedure.
  NO
  - Check for open in harness..
  - Repair or replace as necessary. And then, go to "VERIFICATION OF VEHICLE REPAIR " procedure.