Genuine Nissan Xterra EGR Valve

Nissan Xterra EGR Valve Parts Questions & Answers

• Valve Assembly-SOLENOID
  14956-38U01
  Q: How does the Exhaust Gas Recirculation (EGR) system,EGR Vacuum Solenoid and EGR Valve work and how to inspect and replace on Nissan Xterra?

  A: To decrease the amount of NOx released, a portion of exhaust gases are forced back into the intake manifold by Exhaust Gas Recirculation (EGR) system found in four-cylinder and 3.3L V6 models. This mixture lessens combustion temperatures reducing NOx formation. The EGR system comprises parts like the EGR control solenoid valve, EGR valve, EGR temperature sensor, and EGR control backpressure transducer valve. By use of vacuum signals, PCM operates the EGR control solenoid. In the vacuum system there is a tap in the air intake system while in ported vacuum control system there is a throttle body exposed to manifold vacuum during acceleration. It assists in controlling EGR vacuum signal by monitoring exhaust backpressure; also the PCM takes its orders from EGT sensor on changes happening inside of this passage. Properly function your systems by checking hoses, connections and inspecting for damage, cracks or leaks. Bring engine to operating temperature before testing EGR system allowing it to idle and opening/closing throttle to observe movement of egr valve steam which indicates proper workability of the system if it moves but check vacum signal and connections if it does not move. These can include clogged passages or faulty valves that may need service such as cleaning or replacing diaphragm movements and so on. Additionally, examine voltage signals and operations for an egr control solenoid when you replace it should any be found wanting while blown at coolers should be unclogged then flushed with water. Also when subjected to vacuum this may cause hissing sound but should cease when pressure goes beyond 0.145 psi in case of an egr control backpressure transducer valve leaking . Finally immerse its tip into hot water during resistance checks for an egr temperature sensor so that any marked decrease suggests malfunction. Service or replace them by taking out deposits from mounting surfaces once you have cleaned EGR valve before rechecking for proper installation. For a control solenoid of an EGR system, you can begin by unplugging its electrical connectors then detaching vacuum hose before removing the solenoid and reinstalling it again. An EGR temperature sensor is dismantled by disconnecting electrical connector first then unscrewing the sensor plug.