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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 to LOCK position. Disconnect EGR valve 6-pin harness connector, located at rear of intake manifold. See Figure . Check EGR valve connector for contamination and poor terminal contact. See Figure . 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, perform EGR valve component test. See EXHAUST GAS RECIRCULATION under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. After repair, repeat DTC CONFIRMATION TEST  .
  3. Reconnect EGR valve harness connector. Locate and disconnect ECM harness connector under instrument panel, behind glove box. See Figure . Disconnect ECM harness connectors C51-2 and C51-3 and measure resistance between specified ECM harness connectors and terminals. Resistance should be 20-24 ohms at 68°F (20°C). Also measure resistance between ground and ECM harness connector C51-2 specified terminals. See CHECKING EGR VALVE SYSTEM CIRCUITS RESISTANCE  table. See Figure . If all resistances are as specified, problem is intermittent. See INTERMITTENTS in TROUBLE SHOOTING - NO CODES article. If resistance is not as specified, repair open or short to ground in appropriate circuit. After repair, repeat DTC CONFIRMATION TEST  .
    CHECKING EGR VALVE SYSTEM CIRCUITS RESISTANCE

    Measure Between ECM Harness Connector/Terminal (Wire Color) Measure Between ECM Harness Connector/Terminal (Wire Color)
    C51-2/13 (Light Green/Red) C51-3/4 (Blue/Black)
    C51-2/14 (Green/Yellow) C51-3/4 (Blue/Black)
    C51-2/15 (Light Green/White) C51-3/4 (Blue/Black)
    C51-2/16 (Light Green) C51-3/4 (Blue/Black)
    C51-2/13 (Light Green/Red) Ground
    C51-2/14 (Green/Yellow) Ground
    C51-2/15 (Light Green/White) Ground
    C51-2/16 (Light Green) Ground
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