I recently installed a Tekonsha P3 in my 2003 Super Duty (6.0L PS with factory tow package) as an upgrade fromvthe OEM unit, and Tekonsha says that in order to recognize the trailer I have to have Ford reflash my ECU. I took the truck to Ford yesterday and they told me that they do not have a software to reflash for the 2003's. Has anybody installed the P3 on a 2003 6.0L F-350, and what all did you have to do to get it to work? I really do not want to run new wiring, and I have to tow in 3 days! Thanks in advance!

 

I cannot envision a reason that you would need an ECU update to connect a brake controller. There are 4 wires to your controller, one is power, one is ground, one connects to the brake switch so it knows your foot is on the brake and one goes to the trailer.

Does your controller have power? The P3 should turn on the first time you touch the brakes. If not, check fuses.

How did you connect the P3. Did you use the pre-wired cable from Tekonsha?

Also, I'm confused when you say you replaced the OEM unit. As far as I know, Ford didn't have an OEM brake controller until 2005.

 

Yeah, I unplugged the one that came with the truck and installed the P3 in the same harness using the plug and play harness. The unit powers on fine, but says "No trailer connected" for the first five seconds or so. The controller was changed in 2005_ to one in the dash I believe, but the pre-2005s also had one. It hung down from the bottom of the dash right around the OBD-!! port. Lol, I agree with you, I have no idea why the controller would go through the ECU... seems like a stupid idea to me.

 

As dchamberlain suggested, did you check the fuse going to the brake system for being either not installed or blown? Not for sure just where the fuse would be located - are they still under the brake reservoir in 2003?

 

Don't think it is the fuse. The unit powers on fine, and the other brake controller (oem) worked well before I upgraded.

 

Have you checked the trailer plug (both on the truck and the trailer), and the trailer wiring for corrosion. Check the ground wire to frame connections on both the truck and trailer as well.

I could see a situation where their is enough resistance in the trailer brake circuit to prevent the P3 from detecting the trailer.

 

Actually, I plugged in the old controller, and it recognized the trailer but not the new one. Here is the issue in hand. Sorry it took me a while to snag some pics.

This is the harness that I have. I think it is a six prong, it has a six blades but one center prong.


I had this in my truck. It is the original controller that came with the truck.


I upgraded to this. I bought the harness to make it all "plug and play". I installed it by plugging it into the block under the inspection panel under the steering wheel.


And mounted it in the same location as the OEM.








And when I hit the brake pedal to turn it on, this is what it looks like.


LOVE IT! But then I plug in the trailer, and it flashes between this...


And this.

 

I would still open up the back of the truck connector, and open up the trailer connector and look for corrosion or partially broken wires. Check ground wire to frame connections on the truck and the trailer as well.

Both the original controller and the P3 detect the trailer by putting a small voltage across the brakes. If the original controller uses more voltage, it may push through corrosion where the P3 won't.

 

Looked up under the truck and I did not see any corosion. Same with the trailer and the harness. No broken wires either.

 

David,
Do you have a P3 or aftermarket controller? If so, did your truck come with a factory tow package, and what did you have to do anything different in order to make the controller work, or was it all plug and play?

 

I have the P3 controller. All I had to do was plug it in.

I'm still somewhat confused by the whole OEM controller issue. As far as I know, no such thing existed before 2005. If it did, I've never heard of it. Did you buy the truck new with the brake controller in it? If so, I'd say it must have been a dealer installed aftermarket controller. If you bought it used then the previous owner probably installed it.

Either way, it shouldn't have any effect on the operation of the P3. I suppose it's possible that you got a bad P3. But that doesn't seem likely.

 

Thanks for the tech David. Actually, I did get the truck used but have seen many other 2003-04 350s with the same exact unit installed. Ford also had a direct plug and play harness, so I think it was a factory unit. Unlike the 2005+, my 2003 was not located in the dash pocket next to the upfitter switches. Apparently, on '03-04s they were bolted to the bottom of the dash around the OBDII port. Anyhow, I figured it out. I probed the harness at the signal end behind the controller and found that I got voltage (.-2-3.0V, depending on the slider switch position) when grounding to the chassis. Then, I clipped the DVOM to the ground and signal wires at the harness, and bingo! When I set the DVOM to ohms to close the circuit, the controlled recognized the trailer. Upon the advice of a tech with Tekonsha, I closed the wires on the trailer a little to make the connection tight, and Yatzi! Turned out one of the prongs was just opened a little too much on the trailer end. Thanks again for all the help!

 

Just road tested it... everything is good to go! I'm happier than a pervert at Hooters!

 

First, that is a 7 pin trailer connection, not a 6.

Second, that "Brake Force" controller is not Ford OEM. OEM (Original Equipment Manufacturer) means the part or component was designed into the equipment (in this case, truck) from the get go...

The Brakeforce controller may have simply been a common, inexpensive, and readily available option for dealers to install...Ford, however, did not ever install them.

Ford has, to my knowledge at least as long as the Super Duty has existed, provided a harness in the dash to allow simpler installation of an aftermarket brake controller.

 

Ah, thanks for the info. Like I said, I am new to towing. As for the controller, I assumed it was factory since I have seen so many other F-350s with the same exact model, one recently was from Fla., so it made me think it was not dealership installed. Thanks for the information though, I got it swapped out and working so everything is good now.