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Home >> Lexus >> 1997 >> SC 300 Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Tests W/Codes >> Circuit Tests >> DTC P0325, P0330 - Knock Sensor >> Diagnosis & Repair

Diagnosis & Repair

  1. Access ECM harness connectors behind glove box. Connect Check Harness "A" (SST 09990-01000) to ECM connectors, leaving ECM disconnected. See TEST PREPARATION under SELF-DIAGNOSTIC SYSTEM section. Turn ignition on. Measure resistance between ground and terminals No. 49 (White wire) and No. 50 (White wire) at ECM "B" connector. If both readings are infinite, go tostep 3). If any reading is not infinite, go to next step.
  2. Disconnect knock sensor connector. Using an ohmmeter, check for continuity between knock sensor terminal and knock sensor body. If continuity exists, replace sensor. If continuity does not exist, go to next step.
  3. Check for an open or short circuit in wiring harness between knock sensor and ECM. See appropriate wiring diagram in WIRING DIAGRAMS article. Repair as necessary. If wiring is okay, go to next step.
  4. Substitute knock sensor with a known-good sensor and retest. If malfunction is corrected, replace knock sensor. If malfunction is still present, replace ECM and retest.
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