Circuit Open/Short inspection

1. Disconnect the PCM connector.
2. Inspect the following wiring harnesses for an open or short circuit. (Continuity inspection)
   Fig 1: Identifying Knock Sensor Harness Side Connector Terminals

   Courtesy of MAZDA MOTORS CORP.

Open circuit 

• If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
  • KS terminal A and PCM terminal 2U
  • KS terminal B and PCM terminal 2V

Short circuit 

• If there is continuity, there is a short circuit. Repair or replace the wiring harness.
  • KS terminal A and power supply
  • KS terminal A and body ground
  • KS terminal B and power supply
  • KS terminal B and body ground