Operation CHARM: Car repair manuals for everyone.

HX1 - HX10




NOTE: Ford DOES NOT provide a procedure to perform the following Pinpoint Test without the Rotunda Evaporative Emission System Tester 134-00056 or equivalent.

HX1 - GDTC P0442: Visual Inspection For Small Evaporative Emission System Leaks

Continuous Memory Diagnostic Trouble Code (DTC) P0442 indicates that a fuel vapor leak has been detected [as small as 0.10 cm (0.04 inch)] in the Evaporative Emission (EVAP) system.

NOTE: Prior to performing the following diagnosis inspect the Canister Vent Solenoid (CV) for contamination. A situation may exist where contamination holds open the Canister Vent (CV) solenoid enough to set DTC P0442 and also plugs the port to atmosphere enough to keep system from being vented quickly. After cleaning contamination perform Evaporative Emissions Leak Test HX3. Other possible causes:
- After market parts and accessories nonconforming to the EVAP system specifications.
- Damaged, cross threaded or loosely installed fuel filler cap.
- Small holes or cuts in fuel vapor hoses/tubes (EVAP canister tube, EVAP canister outlet tube or EVAP return tube) in the EVAP system.
- Loose fuel vapor hose/tube connections to EVAP system components.
- EVAP system component [EVAP canister purge valve, fuel tank pressure (FTP) sensor, canister vent (CV) solenoid, fuel vapor control valve tube assembly or fuel vapor vent valve assembly] seals leaking.
- CV solenoid partially open when commanded closed.
- EVAP canister leaking.

- Check for presence of fuel filler cap. (Perform Pinpoint Test Step HX2 before tightening a loose cap or checking for a cross threaded cap).
- Verify that the CV solenoid is properly seated on the EVAP canister (if possible).
- Visually inspect for cut or loose connections to fuel vapor hoses/tubes in following locations:
- EVAP canister to EVAP canister purge valve.
- EVAP canister to fuel vapor vent valve assembly.
- Fuel vapor control valve tube assembly to fuel tank (if applicable).

- Check for fuel filler pipe damage.

Is a fault indicated?

YES CONNECT or REPLACE fuel vapor hoses/tubes as required. REPLACE damaged EVAP system components as necessary. GO to HX2.
NO GO to HX2.

HX2 - Check For Small Evaporative Emission System Leaks From The Evaporative Test Port

NOTE: When performing a check for leaks or blockages in the EVAP system, energize (close) the canister vent (CV) solenoid through the scan tool for a maximum of nine minutes per pinpoint test step. Then de-energize the CV solenoid prior to performing the subsequent pinpoint test step. This is done to assure proper closing of the solenoid.

- Disconnect and plug the EVAP return tube (EVAP canister purge valve to intake manifold) at the intake manifold vacuum source.
- Connect scan tool.
- Key on, engine off.
- Access VPWR PID. If the voltage is not 12 volts or greater, GO to HX6I
- Locate evaporative test port [marked EVAPORATIVE SERVICE PORT DO NOT USE UNREGULATED PRESSURE ABOVE 6.89 kPa (1 PSI)] near EVAP canister purge valve or EVAP canister.
- If vehicle is not equipped with the evaporative test port, GO to HX3.
- Install the Rotunda Evaporative Emission System Leak Tester 31 0-F007 (134-00056) or equivalent at the evaporative test port.
- Close CV solenoid by accessing Output Test Mode on the scan tool.
- Select ALL OFF mode and push START button.
- Regulate the nitrogen or argon gas pressure on the tester to 3.48 kPa (14 in-H 2 0).
- Follow the instructions that come with the EVAP System Leak Tester and pressurize the EVAP system.
- Perform the EVAP system leak test.

Does the pressure on the EVAP system stay above 1.99 kPa (8 in-H 20) and pass the leak test?

YES CHECK for visible damage to fuel filler cap. REMOVE the EVAP system Leak Tester from the evaporative test port. GO to HX3.
NO REMOVE the EVAP system Leak Tester from the evaporative test port. GO to HX3.

HX3 - Check For Small Leaks At Fuel Filler Cap And Evaporative Test Port

- Install the EVAP System Leak Tester at the fuel filler pipe.
- Follow the instructions that come with the EVAP System Leak Tester kit to perform TESTING AT FILLER NECK.
- Access the ultra-sonic detector from the test kit.
- Key on, engine off.
- Close CV solenoid by accessing Output Test Mode on the scan tool.
- Pressurize the EVAP system to 3.48 kPa (14 in-H 20).
- Perform the EVAP system leak test.
- Slowly pass the detector probe around the fuel filler cap and the evaporative test port.

Is an audible change around the fuel filler cap or evaporative test port causing EVAP system leak test to fail?

YES REPLACE fuel filler cap or evaporative test port. When the test port is part of the EVAP canister purge valve, REPLACE the valve. REPEAT Pinpoint Test Step HX3.

For EVAP system passing the leak test: REMOVE EVAP System Leak Tester from fuel filler pipe. RECONNECT and TIGHTEN fuel filler cap only one eighth turn so that cap initially clicks by sound or touch.

PERFORM the Vehicle Preparation for Monitor Repair Verification Drive Cycle and RERUN Evaporative Emission Running Loss Monitor Repair Verification Drive Cycle.

For EVAP system not passing the leak test: REMOVE EVAP System Leak Tester from fuel filler pipe. RECONNECT and TIGHTEN fuel filler cap only one eighth turn so that cap initially clicks by sound or touch.

GO to HX4.
NO REMOVE EVAP System Leak Tester from fuel filler pipe. RECONNECT and TIGHTEN fuel filler cap only one eighth turn so that cap initially clicks by sound or touch.

PERFORM the Vehicle Preparation for Monitor Repair Verification Drive Cycle and RERUN Evaporative Emission Running Loss Monitor Repair Verification Drive Cycle.

HX4 - Small Leak Check For EVAP System With Leak Tester Set At Fill Position

- Install EVAP System Leak Tester at evaporative test port.
- Close canister vent (CV) solenoid by accessing Output Test Mode on the scan tool.
- Select ALL OFF mode and push START button.
- Regulate the nitrogen or argon gas pressure on the tester to 3.48 kPa (14 in-H 20).
- Follow the instructions that come with the EVAP System Leak Tester.
- Turn selector on the Leak Tester to FILL POSITION.
- Pressurize the EVAP system to 3.48 kPa (14 in-H 20).

Does the pressure on the EVAP system hold between 3.43 and 3.53 kPa (13.80 and 14.20 in-H 20)?

YES GO to HX5.
NO DISCONTINUE pressurizing the EVAP system. GO to HX6.

HX5 - Check For Small Leak In The Entire Evap System With Ultra-sonic Detector

NOTE: If the EVAP canister-CV solenoid and fuel tank assemblies are not accessible to perform the following step, refer to Emissions Control Systems or Fuel Delivery and Air Induction for removal procedures.

- Key on, engine off.

NOTE: To assure that the CV solenoid remains closed do not energize the solenoid with the scan tool for more than nine minutes. If necessary, de-energize the CV solenoid with some time passing between checks. Close the CV solenoid closed by accessing Output Test Mode on the scan tool.

- Pressurize the EVAP system to 3.48 kPa (14 in-H 20).
- Access the ultra-sonic detector from the EVAP System Leak Tester kit.
- Slowly pass the detector probe over the EVAP system at the following locations:
- EVAP return tube to EVAP canister purge valve.
- EVAP canister purge valve to EVAP canister-CV solenoid assembly.
- EVAP canister-CV solenoid assembly to fuel tank.
- Fuel filler cap and fuel filler pipe.

Is a sudden audible change indicated?

YES RECONNECT loose or REPLACE damaged fuel vapor hoses/tubes (EVAP return tube, EVAP canister purge outlet tube and EVAP canister tube). GO to HX6.
NO DISCONTINUE pressurizing EVAP system. GO to HX6.

HX6 - Check For Small Evaporative Leak From EVAP Return Tube To The EVAP Canister With Ultra-sonic Detector

- Disconnect the EVAP canister tube (from the fuel tank) at the fuel vapor tee between the EVAP canister purge valve and EVAP canister (or at the F-fitting on the EVAP canister).
- Plug (cap) the fuel vapor tee (or the F-fitting on the canister).
- Close the CV solenoid by accessing Output Test Mode on the scan tool.
- Pressurize the EVAP system to 3.48 kPa (14 in-H 20) at the evaporative test port.
- Access the ultra-sonic detector from the EVAP System Leak Tester kit.
- Slowly pass the detector probe from the EVAP return tube (intake manifold to EVAP canister purge valve), EVAP canister purge outlet tube (EVAP canister purge valve to EVAP canister-CV solenoid assembly) and canister vent hose assembly.

Is a sudden audible change indicated?

YES RECONNECT loose or REPLACE damaged EVAP return tube, EVAP canister purge outlet tube or canister vent hose assembly. REPEAT Pinpoint Test Step HX6 to VERIFY fuel vapor leak no longer exists. GO to HX7.
NO REMOVE plug from fuel vapor tee (or F-fitting) on the EVAP canister. GO to HX7.

HX7 - Check For Small Evaporative Leak Between EVAP Canister Tube And The Fuel Tank At The Fuel Filler Pipe

NOTE: Remove the fuel vapor vent valve and fuel vapor control valve tube assemblies if they are not accessible to perform the following step.

- Remove the EVAP System Leak Tester equipment from the evaporative test port.
- Remove fuel filler cap.
- Install EVAP System Leak Tester at the fuel filler pipe.
- Plug the open end of the EVAP canister tube (from the fuel tank) at the fuel vapor tee (or at the F-fitting on the EVAP canister).
- Key on, engine off.
- Pressurize the EVAP system at 6.47 to 6.97 kPa (26 to 28 in-H 20) with selector on the Leak Tester at FILL POSITION.
- Access the ultra-sonic detector from the EVAP System Tester kit.
- Slowly pass the detector probe from the EVAP canister tube to the fuel tank, checking the FTP sensor, fuel vapor vent valve(s),fuel vapor control valve and fuel filler pipe.

Is a sudden audible change indicated?

YES RECONNECT loose or REPLACE damaged fuel vapor hoses/tubes (EVAP canister tube). REPLACE damaged EVAP system component as necessary. REPEAT Pinpoint Test Step HX7 to VERIFY a leak no longer exists. GO to HX8.
NO GO to HX8.

HX8 - Verification Leak Check On The EVAP System At The Fuel Filler Pipe

- Reconnect the EVAP canister tube to the fuel vapor tee (or the F-fitting on the EVAP canister).
- Key on, engine off.
- Close the CV solenoid by accessing Output Test Mode on the scan tool.
- Regulate the nitrogen or argon gas pressure on the tester to 3.48 kPa (14 in-H 20).
- Pressurize the EVAP system to 3.48 kPa (14 in-H 20) at the fuel filler pipe.
- Follow the instructions that come with the EVAP System Leak Tester. Perform the EVAP system leak Test.

Does the EVAP system pass the leak test?

YES REMOVE the EVAP System Leak Tester from the fuel filler pipe. REINSTALL the fuel filler cap. TIGHTEN the cap only one eighth turn so that the cap initially clicks by sound or touch. RECONNECT the EVAP return tube to the intake manifold vacuum. PERFORM the Vehicle Preparation for Monitor Repair Verification Drive Cycle and RERUN Evaporative Emission Running Loss Monitor Repair Verification Drive Cycle.
NO Begin at Pinpoint Test Step HX4 and locate a small leak that still exists. Proceed to Pinpoint Test Step HX8 afterwards to VERIFY repair. REMOVE the EVAP System Leak Tester. REINSTALL the fuel filler cap. TIGHTEN the cap only one eighth turn so that the cap initially clicks by sound or touch. RECONNECT the EVAP return tube to the intake manifold. PERFORM the Vehicle Preparation for Monitor Repair Verification Drive Cycle and RERUN Evaporative Emission Running Loss Monitor Repair Verification Drive Cycle.

HX10 - DTC P0443: Inspect EVAP Canister Purge Valve Circuit For Intermittent Failure

Continuous Memory Diagnostic Trouble Code (DTC) P0443 may indicate an intermittent EVAP canister purge valve circuit failure. Possible causes:
- Intermittent EVAP canister purge valve ORVPWR circuit open.
- Damaged EVAP canister purge valve.

- Rerun KOEO KOER Self-Tests and retrieve Continuous Memory DTCs.

Is DTC P0443 present in Continuous Memory Self-Test only?

YES The fault that produced Continuous Memory DTC P0443 can be intermittent. GO to HX16.
NO GO to HX11.