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Home >> Kia >> 2003 >> Spectra Base, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0325: Knock Sensor Circuit Malfunction >> Test Procedure
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Test Procedure

  1. Turn ignition off. Connect Hi-Scan Pro/Kia Data Pro Scan tool or equivalent to OBD-II Data Link Connector. See Figure . Turn ignition on. Monitor knock sensor voltage signal, voltage should be 2.0-3.0 volts. If voltage is as specified. Problem is intermittent, check knock sensor and ECM for proper harness connections and go to step  8 . If voltage is not as specified, go to next step.
  2. Start engine. Using Hi-Scan Pro/Kia Data Pro Scan tool or equivalent, monitor knock sensor voltage signal, from idle speed to 3000 RPM. Voltage should increase. If voltage is as specified, check if other DTC is set, do all repairs associated with that other DTC before continuing this procedure and go to next step. If no other DTC is set, go to next step.
  3. Turn ignition off. Thoroughly check knock sensor. Also check for loose, bent, corroded, contaminated, deteriorated or damaged sensor and ECM connectors terminals. If sensor and connector terminals are okay, go to next step. If sensor or connector terminals are faulty, repair or replace as necessary and go to step  8 .
  4. Disconnect knock sensor 3-pin harness connector. See Fig 1 . Disconnect ECM 81-pin harness connector. See Figure . Measure resistance between sensor connector terminal No. 1 (Yellow/Blue wire) and ECM connector terminal No. 19. Also measure resistance between sensor connector terminal No. 2 (Yellow/Green wire) and ECM connector terminal No. 20. Both resistances should be below one ohm. If resistances are as specified, go to next step. If any resistance is not as specified, repair open circuits as necessary and go to step  8 .
  5. With knock sensor and ECM harness connectors disconnected. Measure resistance, between ground and sensor connector terminal No. 3 (Black wire). Resistance should be below one ohm. If resistance is as specified, go to next step. If resistance is not as specified, repair open circuit at sensor ground wire as necessary and go to step  8 .
  6. With knock sensor and ECM harness connectors disconnected. Turn ignition on. Measure voltage between ground and sensor connector terminal No. 1 (Yellow/Blue wire). Voltage should be below 0.5 volts. If voltage is as specified, go to next step. If voltage is not as specified, repair short circuit as necessary and go to step  8 .
  7. Turn ignition off. With knock sensor and ECM harness connectors disconnected. Measure resistance between ground and sensor connector terminal No. 1 (Yellow/Blue wire). Also measure resistance between sensor connector terminals No. 1 (Yellow/Blue wire) and sensor connector terminal No. 2 (Yellow/Green wire). Both resistances should be infinite. If resistances are as specified, temporarily install a known good knock sensor and check for proper operation. If problem is corrected, replace knock sensor and go to next step. If any resistance is not as specified, repair short circuit as necessary and go to next step.
  8. After repair, return vehicle to original condition. Clear codes using Hi-Scan Pro/Kia Data Pro Scan tool or equivalent. Verify repairs by driving vehicle and monitoring for pending codes. If DTC is set during test drive, follow appropriate DTC test procedure.
Fig 1: Identifying Knock Sensor Connector Terminals
G00102684Courtesy of KIA MOTORS AMERICA, INC.
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