Exhaust Gas RECIRCULATION (EGR) System Test
NOTE:
EGR systems contain different components and have different operating parameters depending on application. See Figure-29. When testing EGR system and components, use proper illustration to determine component location.
- Ensure EGR vacuum modulator filter is clean and in good condition. Clean filter with compressed air (if necessary).
- Using "T" connector, install vacuum gauge in vacuum line to EGR valve. Start engine. Ensure engine runs idles smoothly to ensure proper seating of EGR valve.
- Install Jumper Wire (SST 09843-18020) between terminals TE1 and E1 of data link connector No. 1, located in engine compartment. See Figure.NOTE: The EGR system components can 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 RPM. See EGR TESTING SPECIFICATIONS table. No vacuum reading should be obtained.
- Warm engine to normal operating temperature. Operate engine at specified engine RPM again. See EGR TESTING SPECIFICATIONS table. Ensure a low vacuum reading is now obtained.
- To check EGR valve operation, remove vacuum hose from 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.
EGR TESTING SPECIFICATIONS
| Application | Minimum Temperature | Engine RPM |
|---|---|---|
| Corolla | 117°F (47°C) | 2500 |