Knock Sensor: Miata

Disconnect Knock Sensor (KS) connector. Using ohmmeter, measure resistance between KS terminal "A" (White wire) and KS body. Resistance should be about 560,000 ohms at 68°F (20°C). If resistance is not as specified, replace KS. If KS resistance is within specification, check for open or short circuit in wiring harness. Disconnect KS and PCM 31-pin harness connectors. Perform following circuit inspections:

• Open Circuit Inspection
  
  Check for continuity between KS terminal "A" (White wire) and PCM 31-pin harness connector terminal 4M through common connector. If continuity is not present, repair or replace open wiring harness as necessary.
• Short Circuit Inspection
  
  Check for continuity to ground between KS terminal "A" (White wire) and PCM 31-pin harness connector terminal 4M. If continuity is present, repair or replace shorted wiring harness as necessary.