Hi,
I have finally got around to getting a thread started that captures my notes and findings in regards to getting a brake controller operational for my 2004 X5 4.4. I figured I would throw this in a separate thread to avoid it getting buried in the pages and pages of tow hitch installation threads already out there. Hope it helps.
To start, my X5 did not come with the factory hitch. I scored one from a dealer, mounted it up and wired it in with the factory harness and control module. For the short term, towing my non-brake, single axle, standard bulb, 4-pin trailer harness, this worked fine. I didn't need a brake controller, the PDC was disabled when I plugged in the trailer, the signals blinked at the proper rate, no programming was required. Bliss.
Then I needed to tow a trailer with dual axle, brakes, 7-pin connector. I looked at the hard wired solutions and having to tap in the modules up at the front of the car - not desirable. I came across the Tekonsha Prodigy RF Wireless unit.
Tekonsha Prodigy RF Wireless Trailer Brake Controller - 1 to 3 Axles - Proportional Tekonsha Brake Controller 90250
All indicators were that it would work. I called etrailer's tech support and they said it uses the signals from the connector for "brake" to activate the braking. This was perfect as the factory harness did not have the "brake" signal in it. So I ordered up the controller and prepped for the first tow. Great price, service and shipping. No issues with the etrailer folks.
Notes on the unit:
- It mounts to the trailer and plugs into the X5. Pretty straightforward. No wiring and/or programming required on the X5. You only have to plug the wireless controller part into the cigarette lighter for power and control from the driver's seat.
- I was renting a trailer, so drilling screws into the rental frame was a no-no, so I had to make up a bracket. It was pretty simple. I took a flat piece of aluminum and bent it in an "S" shape to position the module such that the top cleared the trailer frame (as per mounting instructions).
- I used heavy duty zip ties to secure the unit to the frame. I put some large headed screws into the unit's mounting holes to keep the zip ties from slipping off the end.
- The cable from the Tekonsha unit to the X5 is long enough to not have to worry. I wrapped the spare length around the jack without issues.
- Then the trailer cable plugs into it. Finding a spot on the frame rails that allows the safety wire, input and output plugs to clear, plus has it poking above the rail, left me with just one spot on the rental.
- Pairing was exactly as the instructions said. No issues. Once it was paired, I could unplug the unit from the X5 and/or the wireless unit from up front and it would retain the pairing. Some people who had had issues pairing on certain vehicles do the pairing on another car and then transfer the unit to their car (some VW's had this issue I think - my X5 did not).
- I could use the manual button on the wireless controller to activate the brakes to whatever level I wanted, whenever I wanted.
- There are several levels of boost. Select according to load.
Trailer items to note:
- The rental trailer I had was a mix of standard and LED bulbs. They all worked, but they made the X5 signals blink like crazy. No bulb out errors appeared though.
- If you hung around the back of the trailer, every so often you would see a pulse flick in the LED lights. I suspect this was the pulse signal to test the signal circuit. I've heard of other cars on other forums actually disabling the trailer circuits if the signals pulses fail. I towed for 7 or 8 hours without the signals or trailer lights dropping out the whole trip. Only thing was the fast blinking signals. I couldn't stand it.
- I went on a limb and ordered the following 7-pin to 7-pin adapter (also from the etrailer folks). Although no site I found, nor the etrailer site says this will work for BMW's, it wasn't too pricey so I took the risk. This adapter basically cuts the trailer lights out of the brake test circuit and is supposed to fix the fast blinking signals. I tested it tonight and it works.
- The Tow Ready adapter goes between the Tekonsha box mounted on the trailer and the trailer cable. With nothing plugged into the Tekonsha, my signals didn't blink fast, so I knew the issue was after the Tekonsha unit.
Tow Ready Adapter #20142
Trailer Connector Adapter w/ Lamp-Out Sensor Bypass - 7-Way RV to 7-Way RV - Vehicle End Tow Ready Wiring 20142
Cheers.