Ford Racing Performance Parts New Engine Harness - Bumpside Build-On

This is the fuel pressure sensor and it has a big gray plug that's hard to miss. It is on the front of the driver side fuel rail.

Some of the plugs, like this one for the throttle position sensor on the throttle body, have a little red lock tab that you slide in after the plug is clicked into place. These obviously are important.

This plug is for the variable cam timing oil control solenoid. The PCM calculates throttle position, load, and a few other things to vary the cam timing on the '05 and up 4.6L and 5.4L engines for optimal valve control and more power. Remember, there is a cam in each head and two intake/one exhaust valve per cylinder in the Ford three-valve engines.

Along with the variable cam timing oil control solenoids, there is a cam position sensor in the front of each head that needs to be hooked up to the harness.

There is a plug down behind the oil filter on the left side of the engine. This is for the oil temp sensor.

This unique plug goes to the mass air flow sensor in the cold-air tube.

Since this is a drive-by-wire system, there is a plug on the passenger side of the of the throttle body that will work in conjunction with the throttle pedal.

There are a few plugs behind the engine tied up together. The green ones plug into the heated exhaust gas oxygen sensor (5C5Z-9F472-AA), aka HEGO, or O2 sensors. O2 sensors in a closed-loop EFI system monitor the exhaust gases to see how the engine is running and help the PCM make the engine run more efficiently.

There is no distributor on these engines, but they still need to know the position of the crankshaft. The crank position sensor does just this and is on the lower right side of the engine. That's it for the major stuff on the engine itself, though there are a few other little plugs that are easy to figure out where they need to go.

To connect the main engine harness to the cowl wiring harness, this connector with the green cover goes into the PDB once it's opened up. There is a stud in the printed circuit board that holds the connector securely in the PDB.

Both harnesses need to connect to the PCM. The main engine harness plugs into the two outside ports on the PCM. The cowl harness plugs into the center port. Each terminal has a flip-down safety latch to keep them from coming unplugged.

From here, the PDB and PCM can be mounted in the engine compartment or under the dash should you choose. In a production Mustang they are under the hood and thus suitable to be in that environment.

Last but not least is the OBD-II port. Those of you with late-model vehicles have this same plug that's used to help diagnose engine problems and to read codes using an OBD-II scanner. This should be mounted under the driver side area of the dash that's easy to access and also out of the way of your feet. Next month we'll actually be firing up the engine for the first time with the help from the folks at Ford Racing!

Going away from the engine, PCM, and PDB we find ourselves in what should be the cab of your truck. There is plenty of lead on the wiring going to the drive-by-wire throttle pedal. The pedal base is flat and should mount to most any firewall easily with three bolts. The green wire in my left hand will go to the positive side of the fuel pump. The labeled wires in my right hand will go under the dash to the gauges and ignition switch.