I/M EGR System Set Procedure
INSPECTION/MAINTENANCE (I/M) EXHAUST GAS RECIRCULATION (EGR) SYSTEM SET PROCEDUREDESCRIPTION
The purpose of this test is to satisfy the enable criteria necessary to execute I/M readiness diagnostics for the exhaust gas recirculation (EGR) system. The test may be used to set the I/M System Status indicators to YES. The I/M System Status display on the scan tool provides an indication of whether the control module has completed the required tests. The I/M System Status does not indicate that the tests have passed or failed. When all of the diagnostics for a specific system have run and passed, the I/M System Status will update to YES. If a test for a specific system has failed, the I/M System Status will update to YES, indicating a determination was made, even if all of the other tests for that system have not run.
CONDITIONS FOR RUNNING
- The barometric pressure (BARO) is more than 70 kPa.
- The engine coolant is at operating temperature, 80-110°C (176-230°F).
- The intake air temperature (IAT) is less than 50°C (122°F).
- The idle speed is steady.
- The system voltage is between 11-18 volts.
- The transmission state is steady.
- The vehicle speed is greater than 37 km/h (23 mph).
- The A/C state is steady.
DIAGNOSTIC AIDS
The control module only runs the EGR Active Tests during a gradual deceleration with a closed throttle and a vehicle speed above 37 km/h (23 mph). Several deceleration cycles may be necessary in order to accumulate a sufficient number of EGR flow samples. The procedure outlined in the table is for a clear, flat road. If the procedure is performed on a road with a slight down hill grade, the test may acquire the necessary sample counters in one or two decel trips. If the test is interrupted during the procedure, more than ten deceleration cycles may be needed to complete the test. If the status does not update, the test outlined in this procedure can be repeated until the I/M System Status updates to YES.
If there is an impending failure, the system may require more time to run the diagnostic than was allotted in the set procedure. If the test does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information for an indication of why the test does not complete. Some tests may abort due to changes in the conditions while the test is running. For example, changes in engine load, such as a cooling fan or an A/C compressor clutch turning ON, may cause the test to abort.
TEST
