Vehicle applicability: This diagnostic supplement covers multiple Ford vehicles and engines. Follow the application named in the source below. Some references apply to vehicles other than Mustang.
• Relieve the fuel pressure. Refer to the Workshop Manual Section 310-00, Fuel System for the Fuel System Pressure Release procedure.
• Mechanical fuel pressure gauge connected.
• Pressurize the fuel system. Refer to the Workshop Manual Section 310-00, Fuel System for the Fuel System Pressure Release procedure to pressurize the fuel system.
• Ignition ON, engine running.
• Allow the fuel pressure to stabilize.
• Ignition OFF.
• Ignition ON, engine running.
• Access the PCM and control the FP (MODE) PID.
• Run the fuel pump to obtain maximum fuel pressure.
Is the fuel pressure within range for the vehicle being diagnosed?
Yes | No |
|---|---|
GO to H12 . | GO to Pinpoint Test HC . |
H12 CHECK THE FUEL SYSTEM FOR PRESSURE STABILITY - FAST LEAKDOWN
Note: When the fuel pump is commanded off, the fuel pressure may substantially decrease and then stabilize.
Note: During output state control, the fuel pump stays commanded on for approximately 5 seconds.
• Ignition OFF.
• Ignition ON, engine OFF.
• Access the PCM and control the FP (MODE) PID.
• Run the fuel pump to obtain maximum fuel pressure.
• Command the fuel pump OFF.
• Allow the fuel pressure to stabilize.
• Record the stabilized reading.
• Monitor the fuel pressure for 10 seconds.
Does the fuel pressure remain within 34 kPa (5 psi) of the recorded reading after 10 seconds?
Yes | No |
|---|---|
GO to H14 . | GO to H13 . |
H13 CHECK FOR AN EXTERNAL FUEL LEAK
• Inspect the fuel tank, lines, and filler pipe for a fuel leak.
Is a concern present?
Yes | No |
|---|---|
REPAIR as necessary. REFER to the fuel system WARNING information at the beginning of Pinpoint Test HC. GO to Pinpoint Test HC . RESET the keep alive memory (KAM). | For KA with DTCs P0171 or P2195, Unable to duplicate or identify the concern at this time. GO to Pinpoint Test Z . For DTCs P219A, P219B, P219C, P219D, P219E, P219F, P21A0 or P21A1, GO to H14 . |
2016 Mustang workshop publication supplied to Mustang Atlas. Original technical text and illustrations; HTML formatting by Mustang Atlas. Source page numbering is retained for traceability. Follow the configuration, revision, warnings, and cross-references in the material. About this edition.