Using the Evaporative Emission System Trigger Test

The Evaporative Emission System Trigger Test works best in combination with HDS and is found in the "Select Systems" menu on the Scan Tool.





1. Set up the HDS as you normally would to monitor the Evap System by selecting from the "Signal Waveforms" screen the Canister Close Valve, the Canister Purge Valve and the Differential Pressure Sensor (DPS). Set the MS/DIV (millisecond/division) to 300.





2. Make sure the vehicle is running at normal operating temperature, there are no codes present (clear any code before performing test) and the oxygen sensor is active.

3. If all conditions are met, start the Evaporative Emission Test and the Scan Tool will display "Now Trying to Trigger Evap Test". After a few seconds "Start Recording on the HDS System" message will display. At this point click the RUN button on HDS to start recording.





4. About 30 seconds later the message "Wait about 10 seconds then stop recording on the HDS System" will be displayed. After 10 seconds, stop the recording on the HDS. The HDS should have captured the Evaporative Emission System cycle. If the Evap Test did not perform as described above, disconnect and then re-connect the scan-tool before attempting to perform the Evap Test again.

Note:

i) After performing the Evap Test, it may be necessary to cycle the key off and back on to view engine codes and data. This resets the powertrain control module (PCM) communication system.

ii) The Evap Test can only be performed twice during one key on cycle. Turn the engine off and wait about 15 seconds before trying to run the test again.