Diagnostic Aids
WARNING: This page is about a different car, the 2004 Pontiac Vibe. However, it is still accessible from the selected car via links, so may be relevant.
- The EVAP control system is required to detect evaporative emission fuel system leaks as small as 0.020 inch, between the fuel fill cap, and the purge solenoid.
- To help locate intermittent leaks, use the J 41413-200 Evaporative Emissions System Tester (EEST) to introduce smoke into the EVAP system. Move all EVAP components while observing smoke with the J 41413-SPT High Intensity White Light.
- A temporary blockage in the EVAP purge solenoid, purge pipe or EVAP canister could cause an intermittent condition. Inspect and repair any restriction in the EVAP system.
- In order to improve the visibility of the smoke exiting the EVAP system, observe the suspected leak area from different angles with the J 41413-SPT .
- Reviewing the Freeze Frame Records vehicle mileage since the diagnostic test last failed may help determine how often the condition that caused the DTC to be set occurs. This may assist in diagnosing the condition.
- The test for leaks with smoke is performed with the system subjected to positive pressure. The trouble code diagnostic tests for a leak with vacuum or negative pressure. Perform the Purge/Seal test with the scan tool in order to test for leaks using vacuum pressure. Refer to Purge/Seal Function in Service Bay Test . If the Purge/Seal test fails, inspect the EVAP system o-ring seals for failure. O-ring seals can provide a good seal with pressure applied in one direction, but leak when the pressure is applied in the opposite direction.
- Operating the vehicle in Check Mode will increase the ability of the powertrain control (PCM) module to detect engine control system malfunctions. Refer to Check Mode in Service Bay Test .
- For intermittent conditions refer to Intermittent Conditions .