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6-14 Chapter 6 Emissions and engine control systems 6.5 Checking the EGR valve (arrow) using a hand-operated vacuum pump 6.1b EGR system component location - V6 engine 1 Solenoid/transducer 2 EGR valve 3 Tube from the exhaust ports through the EGR The EGR system consists of the EGR valve, the EGR solenoid/transducer assem- the solenoid to control vacuum to the trans- ducer. The transducer is controlled by the EGR valve. When exhaust system back- pressure becomes high enough, it fully the PCM de-energizes the solenoid and allows vacuum to flow through the trans- the engine for combustion. Check EGR valve Refer to illustration 6.5 3 Check the condition of all the EGR sys- tem hoses and tubes for leaks, cracks, kinks or hardening of the rubber hoses. Make sure with the EGR check. 4 Check the Vehicle Emission Control Information (VECI) label (see Section 1) for the correct EGR system hose routing. Reroute the hoses if necessary. Detach the vacuum hose from the top of the EGR valve and attach a hand-operated 6 Start the engine and warm it to its nor- mal operating temperature. Apply approximately 5 in-Hg of vacuum to the EGR valve with the engine at idle indicates that the EGR system is operating change, this indicates a possible faulty EGR Turn off the engine. 8 Next, apply approximately 15 in-Hg of vacuum to the EGR valve and see if the stem plugged with carbon deposits, do not attempt to scrape them out, replace it with a new one. Apply approximately 15 in-Hg of vac- uum to the EGR valve and see if the vacuum the EGR valve or the vacuum pressure does- n't remain constant, the diaphragm inside the Solenoid/transducer assembly Refer to illustration 6.10 10 Disconnect the electrical connector from the solenoid (see illustration). Detach vacuum hose connecting the solenoid/transducer to the intake manifold Attempt to apply approximately 15 in- Hg of vacuum to the solenoid. No vacuum Next, connect one of the solenoid elec- trical terminals to the positive remote battery another jumper wire, connect the other termi- 6.10 EGR solenoid/transducer (arrow) - V6 engine shown solenoid - be careful not to short them Check the transducer diaphragm; detach the back-pressure hose from the Replacement Note: Because the EGR valve and sole- noid/transducer are a calibrated unit, they 14 Disconnect the electrical connector and vacuum hoses from the solenoid/transducer |