Brake Cut Off Mod - How To Guide?

[jackbh241]

Hi all,

I know this has been posted a million times but I was just wondering if anyone has written a succinct how to guide for the brake cut off mod on the m35? Can only find 100 page discussions and no actual how to.

Any help would be greatly appreciated and sorry about the noob-ness.

[Commsman]

All info you need is here: http://www.skylinesaustralia.com/forums/topic/397960-m35-stagea-brake-cut-off-mod/page-1, but read all the way thru to get all the tips.

There's no fully detailed DIY 'how to' as such, mainly because it's really easy.

Find wire on ECU.

Cut wire.

Run to switch or some other 12V source to allow ECU to 'reset' CEL.

Edited December 26, 2013 by Commsman

[scotty nm35]

Don't worry about running it to a 12V source. I have had to replace an ecu which blew from fiddling around with 12V to pin 55.

Just cut the wire and put a switch over the cut. Run it to wherever you need to mount the switch.

[Rudi_ARX-TURBO]

and the purpose of this is ? better take off?

[Brick]

The ecu doesnt allow full acceleration for the first 3 seconds after the brakes have been applied. But cutting the brake wire stops the ecu knowing you have braked.

[Brick]

  On 27/12/2013 at 8:14 AM, Rudi_ARX-TURBO said:

and the purpose of this is ? better take off?

It also makes it possible to do the big stall ups I was doing the night we went to WSID Rudi

[joshm35]

Then again its a wagon. Not a gtr

[Commsman]

  On 26/12/2013 at 12:54 PM, scotty nm35 said:

Don't worry about running it to a 12V source. I have had to replace an ecu which blew from fiddling around with 12V to pin 55.

Just cut the wire and put a switch over the cut. Run it to wherever you need to mount the switch.

Sounds like someone did something wrong then. 12V is 12V. How does the ECU know if you've got your foot on the brake or the wire is connected to the reverse lights (for example)?

  On 27/12/2013 at 9:08 AM, joshm35 said:

Then again its a wagon. Not a gtr

True, but why does anyone do mods at all? This is about the easiest mod & best bang-for-buck of any available for a M35 imo. Even if you never drag it ('cause it's a wagon, not a GTR ), being able to give it more than 30% throttle immediately after you've braked for a corner is worth the few minutes spent doing it.

Edited December 27, 2013 by Commsman

[Rudi_ARX-TURBO]

  On 27/12/2013 at 9:03 AM, Brick said:

It also makes it possible to do the big stall ups I was doing the night we went to WSID Rudi

did it take you long to do the mod?

[Brick]

  On 27/12/2013 at 10:28 AM, Rudi_ARX-TURBO said:

did it take you long to do the mod?

Not really. The wires going into the ecu don't have much play so it was fiddly , but other then that it's prob a 30 min jon by the time you pull the kick panels off etc.

[joshm35]

[quote name="Commsman" post="7154590" timestamp="1388140065"

True, but why does anyone do mods at all? This is about the easiest mod & best bang-for-buck of any available for a M35 imo. Even if you never drag it ('cause it's a wagon, not a GTR ), being able to give it more than 30% throttle immediately after you've braked for a corner is worth the few minutes spent doing it.

My reason for not doing is 'Not' because its a wagon, its that im color blind and cant figure out what wire to cut....

[scotty nm35]

Pin 55, not hard to find mate, you don't need the color... Just makes it easier.

Perhaps you can get someone color capable to tell you if you have the correct wire?

ECU_PINOUTS 13_12_10.PDFFetching info...

[joshm35]

Yeah. Might catch up with leon soon

[Rudi_ARX-TURBO]

  On 27/12/2013 at 10:32 AM, Brick said:

Not really. The wires going into the ecu don't have much play so it was fiddly , but other then that it's prob a 30 min jon by the time you pull the kick panels off etc.

did you have to connect to 12v power josh? eg cigaret socket

[Brick]

  On 27/12/2013 at 11:38 PM, Rudi_ARX-TURBO said:

did you have to connect to 12v power josh? eg cigaret socket

No just throw a switch across the cut wire. Then when the car throws the code. Just flick the switch on and hit the brakes a few times

[Commsman]

  On 27/12/2013 at 4:11 PM, joshm35 said:

Yeah. Might catch up with leon soon

Let me know next time you're driving south into NSW & I'll do it for you Josh.

[joshm35]

  On 28/12/2013 at 12:47 AM, Commsman said:

Let me know next time you're driving south into NSW & I'll do it for you Josh.

cheers leon. I think rob (galaxieman 1963) was going to do a meet and greet soon so ill tag along with uim for s drive.

[joshm35]

  On 27/12/2013 at 11:38 PM, Rudi_ARX-TURBO said:

did you have to connect to 12v power josh? eg cigaret socket

the main 12v power source used is the reverse light circuit which can be found in boots top panel where compliance putsvthe baby seat holding points. All you will need is a test light to find the wire once the reverse gear is selected. Hope that makes sence

[Rudi_ARX-TURBO]

  On 28/12/2013 at 1:25 AM, joshm35 said:

the main 12v power source used is the reverse light circuit which can be found in boots top panel where compliance putsvthe baby seat holding points. All you will need is a test light to find the wire once the reverse gear is selected. Hope that makes sence

would you do this on the ecu wirring for reverse?

[scotty nm35]

  On 27/12/2013 at 11:43 PM, Brick said:

No just throw a switch across the cut wire. Then when the car throws the code. Just flick the switch on and hit the brakes a few times

This. ^^

As there are many other people who are going to read this, just crimp some spade terminals onto the wires and run it to a switch, that way you can easily reset the code every month or two.

Leon seems to think everyone is an electronics guru, but there is absolutely no need to automate such a simple signal. All the ecu needs is a 5 second burst of power which is easily automated but I have seen so many wiring faults caused by DIY brake cut fiddling after owners reading threads like this... Now I just recommend the simple wire cut. (unless you feel very confident).