Diagnostic Aids
- A leak in the EVAP system can be verified by the use of the flow meter on the J 41413-200 Evaporative Emissions System Tester (EEST). See Special Tools . Refer to J 41413-200 operation manual for flow meter use.
- To help locate intermittent leaks, use the J 41413-200 to introduce smoke into the EVAP system. See Special Tools . Move all EVAP components while observing smoke with the High Intensity White Light.
- To improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the High Intensity White Light.
- A condition may exist where a leak in the EVAP system only exists under a vacuum condition. By using the scan tool Purge/Seal function to create a vacuum, seal the system and observe the FTP parameter for vacuum decay, this type of leak may be detected.
- For intermittent conditions, refer to Testing for Intermittent Conditions and Poor Connections .
- Introducing smoke in 15-second intervals may allow smaller leak areas to be more noticeable. When the system is less pressurized, the smoke will sometimes escape in a more condensed manner.