Inspection and Verification

WARNING: This page is about a different car, the 2004 Lincoln LS. However, it is still accessible from the selected car via links, so may be relevant.

Verify the customer concern is with the evaporative emission (EVAP) system.

Visually inspect the following for obvious signs of mechanical damage.

VISUAL INSPECTION CHART

Mechanical
Fuel filler cap EVAP test port EVAP canister assembly or canister vent solenoid EVAP lines or hoses Vacuum lines or hoses

If the concern remains after the inspection, connect the scan tool to the data link connector (DLC) located beneath the instrument panel and select the vehicle to be tested from the scan tool menu. If the scan tool does not communicate with the vehicle:
- Check that the program card is correctly installed.
- Check the connections to the vehicle.
- Check the ignition switch position.
If the scan tool still does not communicate with the vehicle, refer to the scan tool manufacturer's manual.
Carry out the DATA LINK DIAGNOSTICS test. If the scan tool responds with:
- CKT914, CKT915 or CKT70 = ALL ECUS NO RESP/NOT EQUIP, refer to MODULE COMMUNICATIONS NETWORK .
- NO RESP/NOT EQUIP for PCM, refer to the INTRODUCTION article.
- SYSTEM PASSED, retrieve and record the continuous diagnostic trouble codes (DTCs), erase the continuous DTCs and carry out the PCM KOEO self-test.
If the DTCs retrieved are related to the concern, go to PCM DIAGNOSTIC TROUBLE CODE (DTC) INDEX .
If the concern remains after the inspection, determine the symptom. GO to SYMPTOM CHART .

PCM DIAGNOSTIC TROUBLE CODE (DTC) INDEX

DTC	Description	Source	Action
P0442	Small leak detected in EVAP system (As small as 1.02 mm [0.040 inch])	PCM	Go To PINPOINT TEST A: DTC P0442 SMALL LEAK IN EVAP SYSTEM, DTC P0456 VERY SMALL LEAK IN EVAP SYSTEM, DTC P0457 MISSING OR LEAKING FUEL FILLER CAP .
P0455	Major leak or no flow detected	PCM	Go To PINPOINT TEST B: DTC P0455 MAJOR LEAK OR NO FLOW DETECTED OR DTC P1443 VERY SMALL OR NO PURGE FLOW DETECTED IN SYSTEM .
P0456	Very small leak detected in EVAP system (as small as 0.051 mm [0.020 in])	PCM	Go To PINPOINT TEST A: DTC P0442 SMALL LEAK IN EVAP SYSTEM, DTC P0456 VERY SMALL LEAK IN EVAP SYSTEM, DTC P0457 MISSING OR LEAKING FUEL FILLER CAP .
P0457	Check for missing or leaking fuel filler cap	PCM	Go To PINPOINT TEST A: DTC P0442 SMALL LEAK IN EVAP SYSTEM, DTC P0456 VERY SMALL LEAK IN EVAP SYSTEM, DTC P0457 MISSING OR LEAKING FUEL FILLER CAP .
P1443	Very small or no purge flow detected	PCM	Go To PINPOINT TEST B: DTC P0455 MAJOR LEAK OR NO FLOW DETECTED OR DTC P1443 VERY SMALL OR NO PURGE FLOW DETECTED IN SYSTEM .
P1450	Excessive vacuum detected in the fuel tank	PCM	Go To PINPOINT TEST C: DTC P1450 EXCESSIVE VACUUM DETECTED IN THE FUEL TANK .
-	Any other PCM DTC	PCM	REFER to the INTRODUCTION article.