I/M EVAP System Set Procedure
INSPECTION/MAINTENANCE (I/M) EVAPORATIVE EMISSION (EVAP) SYSTEM SET PROCEDURE
DESCRIPTION
The purpose of this procedure is to satisfy the enable criteria necessary to execute inspection/maintenance (I/M) readiness diagnostics for the Evaporative Emission (EVAP) System. The procedure may be used to set the EVAP I/M System Status display on the scan tool to YES. The EVAP I/M System Status display indicates whether or not the control module has completed the readiness diagnostics. The readiness diagnostics complete when all DTCs comprising the diagnostics run and pass, or any DTC comprising the diagnostics illuminates the malfunction indicator lamp (MIL). If the diagnostics pass during one drive cycle, seventeen hours must elapse, regardless of whether the vehicle is driven or not. Then, the diagnostics will run again during the next drive cycle in which the conditions for running are met. Once the diagnostics have passed during the third drive cycle, the EVAP I/M System Status display will be updated to YES. A failed or aborted diagnostic will require the vehicle to cool down in order to meet the enable criteria for another drive cycle. Therefore, performing a visual inspection prior to running the EVAP test may prevent having to repeat the drive cycle.
CONDITIONS FOR RUNNING
- At least 17 hours have elapsed since the last drive cycle met the Conditions for Running.
- The difference between the start-up engine coolant temperature (ECT) and the start-up intake air temperature (IAT) is less than 8°C (14.4°F).
- The barometric pressure (BARO) is more than 74 kPa.
- The start-up ECT is between 4-30°C (39-86°F).
- The start-up IAT is between 4-30°C (39-86°F).
- The fuel level is between 15-85 percent.
- The battery voltage is between 10-18 volts.
- The fuel level does not increase more than 9 percent during this drive cycle.
- The engine run time is at least 10 minutes.
- The vehicle has been driven at least 5 km (3.15 miles) this drive cycle.
- The estimated ambient temperature at the end of this drive cycle is between 2-32°C (36-89°F).
- The shutdown ECT is at least 70°C (158°F).
- The ignition is turned OFF for at least 1 hour after this drive cycle.
DIAGNOSTIC AIDS
Extreme high or low ambient temperatures may prevent the EVAP System Tests from initiating. A loose fuel cap may cause a test to abort or fail and prevent the I/M System Status from updating. A failed or aborted diagnostic will require the vehicle to cool down in order to meet the enable criteria for another drive cycle.
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 diagnostic does not run after numerous attempts and no DTC is set, review the appropriate scan tool data list and the service information. This will give an indication of why the test does not complete. Some diagnostics 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 diagnostic to abort.
TEST
