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Home >> Suzuki >> 2003 >> Vitara 4D Utility, RWD, Automatic >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0449: EVAP System Vent Control - Circuit Malfunction (With ORVR System) >> 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 A-4: ENGINE SYSTEM CHECK  under SYSTEM TESTS, then go to next step.
  2. Turn ignition switch to LOCK position. If using scan tool, go to next step. If not using scan tool, locate ECM 30-pin harness connector C51-2 under instrument panel, behind glove box. See Figure . Check ECM connector for contamination and poor terminal contact. If contamination or poor terminal contact is found, repair as necessary and repeat DTC CONFIRMATION TEST  . If contamination or poor terminal contact is not found, turn ignition switch to ON position and measure voltage between ground and ECM harness connector C51-2 terminal No. 5 (Purple/Red wire). See Figure . If voltage is not 10-14 volts, go to next step. If voltage is 10-14 volts, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article. After repair, repeat DTC CONFIRMATION TEST  .
  3. Ensure ignition switch is in ON position. Using scan tool, clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES  under SELF-DIAGNOSTIC SYSTEM. While turning EVAP-CVV ON and OFF with scan tool, measure voltage between ground and ECM harness connector C51-2 terminal No. 5 (Purple/Red wire). See Figure . Voltage should be 10-14 volts when EVAP-CVV is turned ON, and 0-1 volt when EVAP-CVV is turned OFF. If voltage is not as specified, go to next step. If voltage is as specified, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article. After repair, repeat DTC CONFIRMATION TEST  .
  4. Turn ignition switch to LOCK position. Perform EVAP-CVV component test. See EVAP CANISTER VENT VALVE under FUEL EVAPORATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If EVAP-CVV is faulty, replace vent valve. After repair, repeat DTC CONFIRMATION TEST  . If EVAP-CVV is okay, check open or short circuit in Blue/Black wire between ECM and EVAP-CVV. Also check open or short circuit in Purple/Red wire between ECM and EVAP-CVV. If open or short circuit is found, repair as necessary and repeat DTC CONFIRMATION TEST  . If open or short circuit is not found, substitute ECM with a known good unit and repeat DTC CONFIRMATION TEST  .
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