OEM BMW X5 brake controller
07-23-2017, 03:34 PM
#1
Rennlist Member
Thread Starter
OEM BMW X5 brake controller
Anyone installed or used the OE BMW brake controller on an F15 X5? How does it connect? Is there any splicing required? Can. It be unplugged when not in use? Does it work well?
07-23-2017, 11:38 PM
#2
I'm interested to know as well. THis RF unit has some annoying tendencies and dangerous behavior IMO. When I had the OEM hitch installed last year the dealer in Austin said there was no brake controller option yet. On the E70, the cable ran from harness in trunk to front cupholder, where a BMW badged Tekonsha Prodigy P2 sat in a cup holder mount.
07-23-2017, 11:49 PM
#3
Rennlist Member
I use the Tekonsha by BMW. It comes with a long cord that plugs into the factory harness in the rear right cargo area. No splicing required.
I unplug the wire and remove the unit when not in use. Coil up the wire and store it behind the interior panel by the fuse box. I didn't bother running the wire under the carpet/ trim. Just drape it over / between the seats when in use. It also comes with a mount that sits in the cup holder. Works great.
I unplug the wire and remove the unit when not in use. Coil up the wire and store it behind the interior panel by the fuse box. I didn't bother running the wire under the carpet/ trim. Just drape it over / between the seats when in use. It also comes with a mount that sits in the cup holder. Works great.
07-23-2017, 11:55 PM
#4
Rennlist Member
I'm interested to know as well. THis RF unit has some annoying tendencies and dangerous behavior IMO. When I had the OEM hitch installed last year the dealer in Austin said there was no brake controller option yet. On the E70, the cable ran from harness in trunk to front cupholder, where a BMW badged Tekonsha Prodigy P2 sat in a cup holder mount.
07-23-2017, 11:58 PM
#5
Your dealer is wrong. Remove the interior panel over the rear fuse box on pass side cargo area. You will see a black plastic connector with 4 wires connected. That is where the wire for the controller plugs in. I've used the same controller on my 2012, 2015 and 2017 X5 s. I bought it at BMW in 2013 but it is the Tekonsha Prodigy P2.
07-31-2017, 11:28 PM
#6
Three Wheelin'
Tekonsha Prodigy RF Wireless Trailer Brake Controller - 1 to 3 Axles - Proportional
Has anyone got this to work with an F15 X5? Tekonsha Prodigy RF Wireless Trailer Brake Controller - 1 to 3 Axles - Proportional? https://www.etrailer.com/Brake-Contr...sha/90250.html
It requires an 12v wire in order to pair the hand held unit with the main unit that is mounted to the trailer. I got all the new class III OEM BMW Trailer hitch installed (different from E70 kit), but I don't believe they installed the 12v wire so the to units will not pair, unless there is another problem...
Another issue is the 7-way plug from the Prodigy to the X5 does not seem to fit well into the X5 7-way receptacle. No issue with the trailer plug into the Prodigy.
It requires an 12v wire in order to pair the hand held unit with the main unit that is mounted to the trailer. I got all the new class III OEM BMW Trailer hitch installed (different from E70 kit), but I don't believe they installed the 12v wire so the to units will not pair, unless there is another problem...
Another issue is the 7-way plug from the Prodigy to the X5 does not seem to fit well into the X5 7-way receptacle. No issue with the trailer plug into the Prodigy.
08-01-2017, 06:33 PM
#7
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Thread Starter
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08-01-2017, 08:30 PM
#8
Three examples:
1) When your signal light is on in the X5, the brakes in the trailer are pulsed as the light blinks (the controller interprets tail-lights activated together as a brake signal...if one is blinking then...). So as you are braking coming up to a 90 degree turn, you need to take manual control or the trailer will buck, or worse in the rain.
2) If a trailer tail light stops working (LED tail lights can cause this because there is not enough current load) and the X5 decides the bulb is burnt, it will turn off that bulb. When this happens, the brakes stop working because the controller needs two brake light signals to assume you are applying the brakes. I had a ton of trouble when I upgraded to LED tail lights on my trailer. Finally I put a resistor on each light to create a much larger load to make the ECU happy. That brought some other issues, but I think I have things working consistently now.
3) If the trailer plug jiggles, the X5 can decide something is wrong and turn off individual circuits. I've had instances where the controller completely disconnects and stops working, leaving me without trailer brakes for no apparent reason....and not noticing that it has happened until I need the brakes. As the 7-way plugs get old, especially if they are not used often, they corrode/get crap trapped in the contacts that can cause connection issues. I tried lube, cleaning them, etc - I ended up cutting off the plug and putting a new one on.
2&3 are things you can tune out by solving problems as they come up, but they are things that don't happen with a wired brake controller.
In the scary situations I've been saved by the fact that the X5M has ridiculous brakes.
1) When your signal light is on in the X5, the brakes in the trailer are pulsed as the light blinks (the controller interprets tail-lights activated together as a brake signal...if one is blinking then...). So as you are braking coming up to a 90 degree turn, you need to take manual control or the trailer will buck, or worse in the rain.
2) If a trailer tail light stops working (LED tail lights can cause this because there is not enough current load) and the X5 decides the bulb is burnt, it will turn off that bulb. When this happens, the brakes stop working because the controller needs two brake light signals to assume you are applying the brakes. I had a ton of trouble when I upgraded to LED tail lights on my trailer. Finally I put a resistor on each light to create a much larger load to make the ECU happy. That brought some other issues, but I think I have things working consistently now.
3) If the trailer plug jiggles, the X5 can decide something is wrong and turn off individual circuits. I've had instances where the controller completely disconnects and stops working, leaving me without trailer brakes for no apparent reason....and not noticing that it has happened until I need the brakes. As the 7-way plugs get old, especially if they are not used often, they corrode/get crap trapped in the contacts that can cause connection issues. I tried lube, cleaning them, etc - I ended up cutting off the plug and putting a new one on.
2&3 are things you can tune out by solving problems as they come up, but they are things that don't happen with a wired brake controller.
In the scary situations I've been saved by the fact that the X5M has ridiculous brakes.
08-01-2017, 10:46 PM
#9
Rennlist Member
Thread Starter
Three examples:
1) When your signal light is on in the X5, the brakes in the trailer are pulsed as the light blinks (the controller interprets tail-lights activated together as a brake signal...if one is blinking then...). So as you are braking coming up to a 90 degree turn, you need to take manual control or the trailer will buck, or worse in the rain.
2) If a trailer tail light stops working (LED tail lights can cause this because there is not enough current load) and the X5 decides the bulb is burnt, it will turn off that bulb. When this happens, the brakes stop working because the controller needs two brake light signals to assume you are applying the brakes. I had a ton of trouble when I upgraded to LED tail lights on my trailer. Finally I put a resistor on each light to create a much larger load to make the ECU happy. That brought some other issues, but I think I have things working consistently now.
3) If the trailer plug jiggles, the X5 can decide something is wrong and turn off individual circuits. I've had instances where the controller completely disconnects and stops working, leaving me without trailer brakes for no apparent reason....and not noticing that it has happened until I need the brakes. As the 7-way plugs get old, especially if they are not used often, they corrode/get crap trapped in the contacts that can cause connection issues. I tried lube, cleaning them, etc - I ended up cutting off the plug and putting a new one on.
2&3 are things you can tune out by solving problems as they come up, but they are things that don't happen with a wired brake controller.
In the scary situations I've been saved by the fact that the X5M has ridiculous brakes.
1) When your signal light is on in the X5, the brakes in the trailer are pulsed as the light blinks (the controller interprets tail-lights activated together as a brake signal...if one is blinking then...). So as you are braking coming up to a 90 degree turn, you need to take manual control or the trailer will buck, or worse in the rain.
2) If a trailer tail light stops working (LED tail lights can cause this because there is not enough current load) and the X5 decides the bulb is burnt, it will turn off that bulb. When this happens, the brakes stop working because the controller needs two brake light signals to assume you are applying the brakes. I had a ton of trouble when I upgraded to LED tail lights on my trailer. Finally I put a resistor on each light to create a much larger load to make the ECU happy. That brought some other issues, but I think I have things working consistently now.
3) If the trailer plug jiggles, the X5 can decide something is wrong and turn off individual circuits. I've had instances where the controller completely disconnects and stops working, leaving me without trailer brakes for no apparent reason....and not noticing that it has happened until I need the brakes. As the 7-way plugs get old, especially if they are not used often, they corrode/get crap trapped in the contacts that can cause connection issues. I tried lube, cleaning them, etc - I ended up cutting off the plug and putting a new one on.
2&3 are things you can tune out by solving problems as they come up, but they are things that don't happen with a wired brake controller.
In the scary situations I've been saved by the fact that the X5M has ridiculous brakes.
08-01-2017, 10:54 PM
#10
I looked at the OEM wiring harness, and it DOES have a plug for a wired brake controller, so all I need is the cable to string to the front cupholder. i might have to get the $220 package to get the cable since they don't sell it separately (I have a controller left over from my E70).
08-01-2017, 11:00 PM
#11
Rennlist Member
It's been a while since I've had my Land Rover, but I seem to recall issues even with a hard-wired brake controller on a trailer with LED lights and any tow vehicle that has broken bulb sensing via resistance change. I do believe that the wiring a resistor solution referenced above solved that problem, but it's not a simple plug and play fix. May or may not apply here, but something to consider if you still have problems.
08-01-2017, 11:02 PM
#12
Rennlist Member
Thread Starter
It's a function of ECU's management of the trailer interface, and also a function of the old engineering of the RF unit. I don't think it has anything to do with the OEM plug or wiring harness. You have to buy the module and the OEM harness, I don't think you can simply splice into the tail lights a-la uhaul parking lot style.
I looked at the OEM wiring harness, and it DOES have a plug for a wired brake controller, so all I need is the cable to string to the front cupholder. i might have to get the $220 package to get the cable since they don't sell it separately (I have a controller left over from my E70).
I looked at the OEM wiring harness, and it DOES have a plug for a wired brake controller, so all I need is the cable to string to the front cupholder. i might have to get the $220 package to get the cable since they don't sell it separately (I have a controller left over from my E70).
08-01-2017, 11:11 PM
#13
Are you fairly confident that the wired BMW brake controller will not have any of these issues? I just ordered my trailer last week with electric brakes and there may still be time for me to change the order to surge brakes. That brings me to my second question: if you were me, would you try to change to surge brakes or would you stay with electric and buy the BMW controller?
I have had nothing but trouble with the electric brakes.
08-01-2017, 11:26 PM
#14
Rennlist Member
Thread Starter
I was happy with surge on my open trailer. They are brain dead simple and reliable. Noisy/clunky - yes, and you have no way to take over control, but it was never a problem for me. Eventually you need to replace the damper.
I have had nothing but trouble with the electric brakes.
I have had nothing but trouble with the electric brakes.
08-16-2017, 10:53 AM
#15
Verified that the BMW P2 wired controller for the E70 plugs right into the F15/F85 OEM trailer electrics wiring harness. Got it from ECSTuning.
Picked up trailer this morning from storage and the P2 worked great. Thanks for the Tip guys.
Picked up trailer this morning from storage and the P2 worked great. Thanks for the Tip guys.