Re: How to diag a faulty coil pack
There's a TSB on that. It's more than likely your trucks problem. It covers 2003 also.
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04-21-10 MIL ON WITH DTC P0354
Publication Date: October 13, 2004
FORD: 2004 F-150
Some 2004 F-150 vehicles equipped with a 5.4L 3-Valve engine may exhibit the malfunction indicator lamp (MIL) on with diagnostic trouble code (DTC) P0354 (Cylinder Number 4 Primary/Secondary Coil Fault). This condition may be due to the A/C line coming in contact with the number 4 coil wire takeout from main harness loom.
Reroute main harness loom by relocating the two (2) harness retainers on the right hand side of the engine. Inspect both wires of coil takeout number 4 for damage, and for pullout damage of wires at the wire harness connector to coil number 4.
Disconnect and remove the PCM Bracket.
Inspect the wiring harness (12B637) loom at the right hand corner of the engine to determine if there is contact with the A/C line (Figure 1).
NOTE: IF HARNESS IS DAMAGED REFER TO TSB 03-11-06 FOR PROPER REPAIR PROCEDURES.
If contact is present, loosen the harness from the front and rear cam cover studs.
Remove the plastic rear stud retainer from the bottom of the wiring harness. Relocate this retainer approximately 3/4" (20 mm) rearward and fasten it to the TOP of the harness (Figure 2).
Remove the front stud retainer from the harness and reposition the harness as needed to remove any slack that may be present.
Reinstall the retainers on the cam cover studs.
Tape down coil number 4 take out.
Verify there is no contact between the A/C line and the wiring harness (Figure 3).
Eligible Under Provisions Of New Vehicle Limited Warranty Coverage And Emissions Warranty Coverage
OPERATION DESCRIPTION TIME
042110A Check For Diagnostic Trouble Codes, Inspect, And Relocate Wire Harness (For Any Wire Repairs Refer To TSB 03-11-06 Use Actual Time In Accordance With The Warranty And Policy Manual Guidelines) 0.7 Hr.
BASIC PART NO. CONDITION CODE
NOTE: The information in Technical Service Bulletins is intended for use by trained, professional technicians with the knowledge, tools, and equipment to do the job properly and safely. It informs these technicians of conditions that may occur on some vehicles, or provides information that could assist in proper vehicle service. The procedures should not be performed by "do-it-yourselfers". Do not assume that a condition described affects your car or truck. Contact a Ford, Lincoln, or Mercury dealership to determine whether the Bulletin applies to your vehicle. Warranty Policy and Extended Service Plan documentation determine Warranty and/or Extended Service Plan coverage unless stated otherwise in the TSB article. The information in this Technical Service Bulletin (TSB) was current at the time of printing. Ford Motor Company reserves the right to supercede this information with updates. The most recent information is available through Ford Motor Company's on-line technical resources.
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