Component Inspection

Component resistance inspection.
1. Ignition Off.
2. Disconnect knock sensor connector.
3. Measure resistance between terminals 1 and 2 of the sensor connector(Component side).
Specification : Approx. 5^MΩ at 20 °C (68°F)

Fig 1: Measuring Resistance Between Terminals 1 And 2 Of Sensor Connector
Courtesy of HYUNDAI MOTOR CO.
Output signal inspection.
1. Remove knock sensor from vehicle and secure (across mounting boss) in a shop vise.
2. Set up an oscilloscope as follows :
  Channel A (+): terminal 1 (-): terminal 2.
3. Rap on vise with a ball peen hammer while monitoring oscilloscope screen (there should be a spike of less than 1 volt with each hammer strike).
Specification : knock sensor send a voltage spike with hammer strikes
Installation torque inspection.
1. Check the installation torque of the knock sensor.
Specification : Approx. 16 ~ 28N.m(160~250 kg.cm, 11.8~18.4 lb.ft)
Has a problem been found?
YES
- Check knock sensor for contamination, deterioration, or damage. Substitute with a known-good sensor and check for proper operation. If the problem is corrected, replace sensor and then go to VERIFICATION OF VEHICLE REPAIR procedure.
NO
- Check for poor connection between PCM and component: backed out terminal, improper mating, broken locks or poor terminal to wire connection. Repair as necessary and go to VERIFICATION OF VEHICLE REPAIR procedure.