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Home >> Suzuki >> 1999 >> Grand Vitara JS, Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0400: Exhaust Gas RECIRCULATION (EGR) Flow Malfunction >> Diagnosis & Repair Procedure
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Diagnosis & Repair Procedure

  1. If using scan tool, check EGR system referring to EXHAUST GAS RECIRCULATION (EGR) under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article. If scan tool is unavailable, go to next step.
  2. Turn ignition off. Disconnect EGR valve harness connector. Turn ignition on. Using DVOM, measure voltage between ground and EGR valve harness connector terminals No. 2 and No. 5 (Blue/Black wires). If 10-14 volts exists on both terminals, go to next step. If 10-14 volts does not exist on both terminals, repair open Blue/Black wire. See WIRING DIAGRAMS article. Retest system.
  3. Turn ignition off. Connect EGR valve harness connector. Remove PCM cover, located below right side of instrument panel. Disconnect PCM connectors. Connect one lead of ohmmeter to PCM 28-pin connector "D" terminal No. 20 (Blue/Black wire). While observing DVOM reading, connect other lead of ohmmeter to PCM 28-pin connector "D" terminals No. 4 (Light Green/White wire), No. 5 (Light Green wire), No. 16 (Light Green/Red wire) and No. 17 (Light Green/Yellow wire). Resistance should be 20-24 ohms at each terminal. If resistance is as specified, go to next step. If resistance is not as specified, go to step  5 .
  4. Check for a stuck or faulty EGR valve. Check for clogged EGR passage in intake manifold. Repair as necessary. If EGR valve and passage are okay, check MDP sensor. See SYSTEM & COMPONENT TESTING article. If MDP sensor checks okay, replace PCM. See REMOVAL, OVERHAUL & INSTALLATION article. Retest system.
  5. Check for open or short in Light Green wire, Light Green/White wire, Light Green/Red wire and Light Green/Yellow wire between EGR valve and PCM. See WIRING DIAGRAMS article. Repair as necessary. If wiring between EGR valve and PCM is okay, test EGR valve. See EXHAUST GAS RECIRCULATION (EGR) under EMISSION SYSTEMS & SUB-SYSTEMS in SYSTEM & COMPONENT TESTING article.
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