INT-BMW2 - Need a breakdown on how the brake wires function during remote start sequence.

Question

I'm trying to solve the no start issue on a 2006 525xi using an EVO-ALL & INT-BMW2.

After checking my wiring several times, I feel I need to understand how the brake circuit on the INT-BMW2 module works before I can further troubleshoot.

 

In the image below, I highlighted the stock function of the factory brake wires.

A) What I need to know is a breakdown of what each of the 4 brake wires from the INT-BMW2 module are doing during the remote start sequence.

 

So something like this:

Ingnition on: Brake X &  Brake Y @ 12V.

Starter on (accessory off): Brake Y @ 12V, Brake Z @ 0V.

Engine running: Brake X & Brake Y....

 

B) Also, can I get the actual pin numbers & their corresponding colors for the 14-pin connector on the INT-BMW2? Just want to confirm all the wire colours are in their appropriate pin location.

Answer 1

The pin positions and numbers are on the INT BMW2 guide on page 5, If you look closely there is  a small number 1 right next to the Lt. Blue/Black wire, this is Pin number 1 and Yellow/Black is Pin 7.  On the other row, Lt. Blue is Pin 8 all the way to Yellow which is Pin 14.

 

I will try and get the breakdown of the functionality of the brake wires, we have had a lot of people call about the INT-BMW2, and most issues were related to either connection issues or Car related as in client inside vehicle during testing (motion sensor), testing too fast, car has to sit for a few minutes after locking/arming before other commands are sent.

Comments

Just verify connections are done as follows:

 

INT-BMW2                                    Vehicle

Pink/Black                          Purple/Black Brake switch side

Pink                                   Purple/Black Car/BCM side

Orange                              Brown/Gray Brake switch side  R.S. brake input connects here too

Orange/Black                     Brown/Gray Car/BCM side

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and most issues were related to either connection issues or Car related as in client inside vehicle during testing (motion sensor), testing too fast,

THIS! Most BMW 5 series have a proximity sensor. If someone is in the car when testing the remote start, it will never work. SImilarly when testing, step out of the car, close and LOCK the doors then wait 1-3 minutes before doing trying the remote start.

I feel I need to understand how the brake circuit on the INT-BMW2 module works before I can further troubleshoot.

 The whole setup works by replciating the electrical connections made when human starts teh vehicle. (key in port, press on the brake, press on the push).

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Just verify connections are done as follows:

 

INT-BMW2                                    Vehicle

Pink/Black                          Purple/Black Brake switch side

Pink                                   Purple/Black Car/BCM side

Orange                              Brown/Gray Brake switch side  R.S. brake input connects here too

Orange/Black                     Brown/Gray Car/BCM side

That's exactly how I have wired it, checked it about 4 or 5 times now. 

 

Right now when I try remote star, this is what happens:

1. Press remote start button. Ignition & brake lights come on.
2. As soon as it's about to crank (starter engages for a fraction of a second), the brake lights shut off and the engine does not begin to fully crank. 

I think at step 2, the brake lights should stay on completely for the car to fully crank. This is why I wanted the functionality of the 4 brake wires so I can test what each one is doing during this sequence.

 

So the remote start doesn't work properly until the car has been sitting armed for a few minutes? I will try letting the car sit armed for a few minutes before starting it.

 

PS. I have the tach learned on the Viper 4806 (W2W), do you suggest a timed crank setting for this application?

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Thanks Robert, I will try Lock/arming the car for a few minutes before starting.

 

Does the factory dirarm work in the same manner? Meaning I have to leave the car Locked/Armed for several minutes before it will Unlock/Disarm.

Right now I would leave it for 15 seconds, it unlocks but no disarm.

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The disarm may work the same way.  So ideally all tests should be done as per normal use of the vehicle. Lock doors, leave the car alone 1-3 minutes, then try unlocking to see if it will disarm properly.

I had a client with similar issues 2-3 weeks ago on an 5 series and it all revolved on actually understanding how the vehicle itself works. Spent hours testing wiring for no reason :)

 

Ninja edit: don't sit in the vehicle when performing test.

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Same issue, I've locked/armed the car for 3+ minutes and kept the factory keys outside. It disarms the factory alarm (double beep) before attempting to resmote start.

It's interesting that even after leaving it for several minutes the disarm doesn't happen on unlock, but it does on remote start attempt..

 

Please see the video I made during the start sequence. I tested the Orange/Black wire (which I believe should be sending a 12V brake signal to the BCM).
https://drive.google.com/file/d/0B3Vi6SnV_VMuUktabWlmc3hxNWM/view?usp=sharing

 

I'm aware that I shouldn't be inside the vehicle, but for the sake of testing, I manually pressed the brake during remote start in this video.
https://drive.google.com/file/d/0B3Vi6SnV_VMuS2prX0UyaGNBM1E/view?usp=sharing

 

Is it possible I have a faulty module?

 

Just a note: The Ignition, Accessory, Ground While Running signal from the R.S. tests normal...

• Ignition gives 12V constant throughout the remote start sequence. 
• Accessory cuts out when the R.S, is trying to crank.
• GWR gives a ground signal throughtout the entire remote start attempt.

 

Edit - Service # added to 1st post.

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we watched your videos and a couple of things dont make sense.

In theory, you should not be able to remote start the vehicle while manually pressing on the brake pedal for a couple of reasons.

1. if everything was connected properly, pressing on the brake should not work since we open both brake wires.

2. if for some reason the brake wires are not being held open, then in theory pressing on the brake should shut down your remote starter via the analog brake input wire.

 

One test you can perform is , Put ground on the blue ground out when running wire of the int-bmw2, then manually put a 12v signal on the yellow black accessory wire to simulate acc being turned on, then removing it should crank the vehicle over (int-bmw2 reads the voltage drop from ACC during crank as a signal to crank the vehicle over) once vehicle starts reconnect the 12v to ACC yellow black wire.

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I took pictures of the brake wires, in case I was blind to a wiring mistake. And yes, I did place the brake switch back into its slot.

 

 

 

Okay, I took a video of manually jumping the GWR & ACC signals. Same simptoms as before.... just as I remove the ACC signal, the starter makes a noise for a split second, then nothing.

https://drive.google.com/file/d/0B3Vi6SnV_VMua2R2Y2c1eDlINkk/view?usp=sharing

 

Also not shown in the video, I did the same test again while pushing the brake pedal and it started the engine. But then the engine kept running when I took off the GWR signal... Had to toggle the GWR & ACC signals before the car shut off again.

 

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The other (brown) wire beside the orange is the brake sense input from the R.S.

On the right there is only one wire connected (looks like two from the angle of the photo). It is the pink/black, the tone of the pink may look a little different as I had to extend the length using some spare wire I had.

 

Edit - Here's a another view.

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Could you try this other test,

1 Ground on the GWR

2.12v on ACC wire

3.12v on IGN wire wire

4. remove 12v on ACC wire until vehicle cranks over

5. reconnect 12v on ACC wire when vehicle is running.

Thank you,

p.s. if after this test vehcile reacts the same, do you have another int-bmw2 module to test with?