Engine Controls - System/component Tests - 1.8L: Diagnosis

Engine Controls - System/component Tests - 1.8L: Diagnosis Toyota Corolla VIII

EXHAUST GAS RECIRCULATION (EGR) SYSTEM TEST

Note. EGR systems contain different components depending on application. (Scheme 42) When testing EGR system and components, use proper illustration to determine component location.

Note. When performing EGR system test, it may be necessary to monitor engine RPM by using scan tool. For scan tool connections, see IDLE SPEED & MIXTURE in ADJUSTMENTS article.

Ensure EGR vacuum modulator filter is clean and in good condition. Clean filter with compressed air (if necessary). NOTE: EGR vacuum modulator filter must be installed with coarse side facing upward, away from EGR vacuum modulator.
Using "T" connector, install vacuum gauge in line with vacuum hose on top of EGR valve. Start engine. Ensure engine idles smoothly to ensure proper seating of EGR valve.
Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 on data link connector No. 1 located in engine compartment. see scheme 17 NOTE: The EGR system components must be checked with engine coolant temperature less than minimum temperature and engine at specified engine RPM.
Operate engine with engine coolant temperature less than minimum temperature and at specified engine RPM. See «EGR TESTING SPECIFICATIONS»(ref-22352-S09552282792001010300000) table. No vacuum reading should be obtained.
Warm engine to more than the specified operating temperature. See «EGR TESTING SPECIFICATIONS»(ref-22352-S09552282792001010300000) table. Operate engine at specified engine RPM again. See «EGR TESTING SPECIFICATIONS»(ref-22352-S09552282792001010300000) table. Ensure a low vacuum reading is obtained with engine at the specified RPM.
Disconnect vacuum hose from port "R" on EGR vacuum modulator. (Scheme 41) Using additional hose, connect port "R" on EGR vacuum modulator directly to intake manifold. High vacuum reading should be obtained at specified engine RPM. See «EGR TESTING SPECIFICATIONS»(ref-22352-S09552282792001010300000) table. NOTE: Engine should misfire due to large amounts of exhaust gas being injected into intake manifold.
Remove vacuum hose, vacuum gauge and reconnect original vacuum hoses. To check EGR valve operation, remove and plug vacuum hose, located on top of EGR valve.
Using vacuum pump, apply vacuum directly to EGR valve with engine idling. Engine should run rough or stall. If EGR system does not operate as described, each individual component should be tested. Shut engine off. Remove jumper wire from data link connector No. 1.