H: Fuel Control H: Introduction — 2016 workshop reference 5126

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.

REFER to Section 2, Resetting The Keep Alive Memory (KAM). REPEAT the self-test.

For all others, GO to H22 .

H14 CHECK THE FUEL SYSTEM FOR PRESSURE STABILITY - SLOW LEAKDOWN

• Continue to monitor the fuel pressure for 1 minute.

Does the fuel pressure remain within 34 kPa (5 psi) of the recorded reading (MRFS) or greater than 275 kPa (40 psi) (ERFS) after 1 minute?

Yes	No
For DTCs P219A or P219B, INSTALL a new Universal HO2S. REFER to the Workshop Manual Section 303-14, Electronic Engine Controls. RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM). REPEAT the self-test. For DTCs P219C, P219D, P219E, P219F, P21A0 or P21A1, GO to H15 . For E100 vehicles, GO to H22 . For all others, GO to H16 .	GO to HC12 .

Yes

For DTCs P219A or P219B, INSTALL a new Universal HO2S. REFER to the Workshop Manual Section 303-14, Electronic Engine Controls.

RESET the keep alive memory (KAM). REFER to Section 2, Resetting The Keep Alive Memory (KAM).

REPEAT the self-test.

For DTCs P219C, P219D, P219E, P219F, P21A0 or P21A1, GO to H15 .

For E100 vehicles, GO to H22 .

For all others, GO to H16 .

GO to HC12 .

H15 CHECK FOR ELECTRICAL NOISE

• Ignition OFF.

• Check the crankshaft position (CKP) sensor harness for routing, alterations, incorrect shielding or electrical interference from other systems.

• Check for radio frequency interference and excessive audible generator noise.

Is a concern present?

Yes	No
REPAIR as necessary. Clear the PCM DTCs. REPEAT the self-test.	UNABLE to duplicate or identify the concern at this time. GO to Pinpoint Test Z .

Yes

REPAIR as necessary.

Clear the PCM DTCs. REPEAT the self-test.

UNABLE to duplicate or identify the concern at this time.

GO to Pinpoint Test Z .

H16 CHECK THE SEPARATION LEVEL OF THE ETHANOL, WATER AND GASOLINE MIXTURE IN THE FUEL

Note: This step requires the use of a locally obtained 200 ml beaker and a 25 ml graduated cylinder.

Note: After approximately 3 minutes of standing, the ethanol and water mixes together and settles to the bottom of the 25 ml graduated cylinder. The gasoline rises to the top.

Source reference 5126

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.