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M35 Brake Switch Cutoff Mod

benriches

By benriches,
in Four Door Family & Wagoneers

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benriches Contributor

benriches

Posted
Posted

Disclaimer: There's a lot of people recommending to do this mod, but I haven't seen any idiotproof guides on how to do it. I'm not saying this is the best way to do this mod, it's just how i've done it - and hopefully this will help others, even if they don't follow my way 100%.

Brief overview: The general consensus is that from Factory, M35 Stageas limit throttle to 30% for up to 3 seconds after releasing the brake pedal. This can prevent good launches/coming out of corners faster. By cutting the signal wire to the ECU, we can maintain full throttle immediately after releasing the brake. It is OK to cut this wire, however you will get a Check Engine Light after some time. By rigging it up to a switch, you are able to disable/enable the mod freely.

  1. Behind the glovebox is the ECU. You will need to dissemble the passenger side interior to access this, there's other guides online on how to do this - so I will assume you have your glovebox out and are looking at the ECU.
  2. Pull the plastic off guard off the ECU connector, it clicks off the 4 tabs on each corner.
  3. Find the VIOLET wire with the BLUE stripe - you can see it in pictures 1 + 4 of this post. I cut this wire, and attached either side to a terminal block. You can pick these up from JayCar very cheaply - I used a terminal block because I don't trust myself to solder wires coming directly off the ECU.
  4. I then picked up a small, discrete ON/OFF toggle switch (also from JayCar), which I mounted in my Glovebox - see pictures 2 + 3. Lastly just attach these wires to the remaining spots on the terminal block.
  5. Test the switch while everything is apart - This way you can fix any problems before reassembling.
  6. Done!

Picture 4 of this post explains the above if anyone is unclear.

Some people have hooked this up to the reverse switch in the car, so they don't have to touch the switch ever - however I like the idea of a toggle, so I can limit throttle power when a family member/friend drives the car.

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post-141380-0-68487200-1444126212_thumb.jpg

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benriches Contributor

benriches

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I like it but it's going to be a bit of a stretch to flick the switch when you are driving.

Definitely - Although I think of it more as a valet switch, however. When I drive the car I leave it enabled, if I take the car to a mechanic or lend to a friend I will disable the switch.

Can also disable the mod to clear any CEL that appears. You could mount the switch wherever you like, though - It's just where I put it :)

Daleo Grand Master

Daleo

Posted
Posted

I like it but it's going to be a bit of a stretch to flick the switch when you are driving.

Agreed.

Mine is a latching switch down next to my right knee; push it in, hold down brake lightly for 5 sec, push switch again to release; good to go for another week or more.

scotty nm35 Grand Master

scotty nm35

Posted
Posted

The only Violet with a white line wire I can see is the engine revs to Hicas ecu wire.

Can you take a pic of the back of the plug?

Edit, I just noticed it looks like the correct wire at the top, but the one you pointed to is not actually connected to the switch? or is it just the pic. Looks pink/white.

Never mind, I must be tired. :P

benriches Contributor

benriches

Posted
  • Author
Posted

The only Violet with a white line wire I can see is the engine revs to Hicas ecu wire.

Can you take a pic of the back of the plug?

Edit, I just noticed it looks like the correct wire at the top, but the one you pointed to is not actually connected to the switch? or is it just the pic. Looks pink/white.

Never mind, I must be tired. :P

Yeah got it from the below threads haha - It's definitely the right wire, my colour perception just isn't very good lol.

  • 2 weeks later...
DrLui Collaborator

DrLui

Posted
Posted (edited)

Now that I'm running a MAP sensor I can do cool stuff like video what this brake mod actually does. Enjoy.

Matt

Nice videos, can clearly see what this mod does.

Edited by DrLui
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