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Home >> Suzuki >> 2003 >> Aerio SX, AWD >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0505, DTC P0506 & P0507 >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

NOTE: For better performance and results of this diagnostic procedure, usage of appropriate wiring diagram is recommended. See ENGINE PERFORMANCE in SYSTEM WIRING DIAGRAMS article in ELECTRICAL.
NOTE: Perform all voltage and resistance tests using a Digital Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance, unless stated otherwise in test procedure. Use an ohmmeter to isolate wiring harness shorts or opens.
  1. If engine system check has been performed, go to next step. If engine system check has not been performed, perform TEST D: ENGINE SYSTEM CHECK  under SYSTEM TESTS, then go to next step.
  2. Check idle speed/idle air control duty. See IDLE SPEED under IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS article. If idle speed/idle air control duty is okay, go to next step. If idle speed/idle air control duty is faulty, go to step  4.
  3. Drive vehicle. Using SUZUKI scan tool or equivalent, check if vehicle speed is displayed. If vehicle speed is not displayed, perform test procedure DTC P0500: VEHICLE SPEED SENSOR MALFUNCTION . If vehicle speed is displayed on scan tool, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO-CODES article. If no intermittent problem is found, substitute ECM with a known good unit and repeat DTC CONFIRMATION TEST .
  4. Check air intake system for clog or leaks (vacuum). If clog or leaks are found, repair as necessary and repeat DTC CONFIRMATION TEST . If clog or leak is not found, check fast idle. See COLD (FAST) IDLE under IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS article. If fast idle system is okay, go to next step. If fast idle system is faulty, repair as necessary and repeat DTC CONFIRMATION TEST .
  5. Turn ignition to LOCK position. Perform IAC valve system check. See IDLE AIR CONTROL VALVE SYSTEM CHECK under IDLE CONTROL SYSTEM in SYSTEM & COMPONENT TESTING article. If system is not operating properly, go to next step. If system is operating properly, go to step  7.
  6. Perform IAC valve component test. See IDLE AIR CONTROL VALVE under IDLE CONTROL SYSTEM in SYSTEM & COMPONENT TESTING article. If IAC valve is faulty, replace IAC valve. See IDLE AIR CONTROL VALVE under AIR INDUCTION SYSTEMS in REMOVAL & INSTALLATION article. If IAC valve is okay, check IAC valve circuits (Black/Red wire) and (Green/Red wire). If any circuit is faulty, repair as necessary and repeat DTC CONFIRMATION TEST . If IAC circuits are okay, substitute ECM with a known good unit and repeat DTC CONFIRMATION TEST .
  7. Check components and systems which can cause engine low or high idle: EGR valve malfunction (leakage), EVAP system malfunction, accessory engine load and engine mechanical (engine compression). If all systems and components are okay, go to next step. If any system or component is faulty, repair as necessary and repeat DTC CONFIRMATION TEST .
  8. Adjust idle speed and idle air control duty. See IDLE SPEED under IDLE SPEED & MIXTURE in ON-VEHICLE ADJUSTMENTS article. If specified idle speed and idle air control duty are obtained after adjustment, repeat DTC CONFIRMATION TEST . If specified idle speed and idle air control duty can not be obtained, check idle air passage for clog. If clog is found, repair as necessary and repeat DTC CONFIRMATION TEST . If clog is not found, substitute ECM with a known good unit and repeat DTC CONFIRMATION TEST .
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