A 2007-2008 Chrysler Pacifica may experience a hard start or no start with MIL on and DTC P0452 stored (EVAP pressure switch stuck closed). The hard start or no start most likely occurs when the fuel tank is full from a recent over-fill event.
These conditions can be caused by fuel that has accumulated in the evaporative lines. A liquid sump can trap negative pressure in the canister line even though the fuel tank is vented. The ESIM switch may remain closed due to the blockage. Liquid fuel can be pulled into the purge valve and create a hard-to-start condition.
Installing a fuel/vapor separator will ensure that no liquid will enter the purge valve and the canister line will communicate properly to the fuel tank.
Using a scan tool, (wiTECH) with the appropriate diagnostic procedures available in TechCONNECT, verify that all engine systems are functioning as designed. If DTCs are present other than the one listed above, record them and repair as necessary before proceeding further.
Part needed: 68048869AA (separator, fuel/vapor kit.
Follow the instruction sheet supplied with the kit to install the fuel/vapor separator.
1. Connect wiTECH to the vehicle.
2. Select PCM.
3. Select Systems Test tab.
4. Select and run the “ESIM Forced Monitor Test.” Follow the instructions on the screen.
If the test passed, the repair is complete. If not, further diagnosis is required.
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