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Home >> Kia >> 2003 >> Rio Base, Standard >> 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. 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. 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 Knock sensor and ECM connectors terminals. If sensor and connectors terminals are okay, go to next step. If sensor and connectors terminals are faulty, repair or replace as necessary. Go to step  8 .
  4. Disconnect Knock sensor 3-pin harness connector. See Fig 1 and ECM harness connector "B03". See Figure . Measure resistance between Knock sensor connector terminal No. 1 (Black wire) and ECM connector terminal B03-46. Also measure resistance between Knock sensor connector terminal No. 2 (Red wire) and ECM connector terminal B03-33. 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 or short circuits as necessary. Go to step  8 .
  5. With Knock sensor and ECM harness connectors disconnected. Measure resistance between ground and Knock sensor connector terminal No. 3 (Brown 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 between Knock sensor and ECM connectors or at chassis ground as necessary. Go to step  8 .
  6. With Knock sensor and ECM harness connectors disconnected. Turn ignition on. Measure voltage between ground and Knock sensor connector terminal No. 1 (Black 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. Go to step  8 .
  7. Turn ignition off. With Knock sensor and ECM harness connectors disconnected. Measure resistance between ground and Knock sensor connector terminal No. 1 (Black wire). Also measure resistance between Knock connector terminals No. 1 (Black wire) and No. 2 (Red 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. Go to next step. If any resistance is not as specified, repair short circuit as necessary. 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
G00102678Courtesy of KIA MOTORS AMERICA, INC.
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