Brake Boosting

phunk

I dont, but I can help you with some information from the FSM.

Pulling the fuse is the easy way to do it, but I believe this will cause your brake lights to no longer work, which is not suitable for street or road course use.

Information from the Nissan FSM, copied and pasted (property of Nissan):

P1805 BRAKE SWITCH
Description: Brake switch signal is applied to the ECM through the stop lamp switch when the brake pedal is depressed. This signal is used mainly to decrease the engine speed when the vehicle is being driven.

DTC detecting condition
A brake switch signal is not sent to ECM for extremely
long time while the vehicle is being driven.

3. Check the continuity between stop lamp switch harness connector and ECM harness connector.
Stop lamp switch Connector E110 Terminal 2
ECM Connector M107 Terminal 122


Looking at the ECU Pinout I confirm that terminal 122 at the ECU is the stop lamp signal input. Looks like it is a pink wire.

Also reconfirming this is the Connector M107 layout from the FSM. I have attached an image of a screen shot I took of this connector.

So in summary; You have 3 large connectors at the ECU. Find the one that matches the attached image and pin 122 is the pink wire for brake signal input. If you disconnect this wire, you can brake boost without losing your brake lights. But if you leave it disconnected too long you will get DTC Code P1805. This is why you would rather put a switch inline here rather than just cut the wire... so you can open the circuit when you want to brake boost without interference by the ECM, and then reconnect the signal later so you do not get the code. An alternative could be to disable P1805 in the ECM if you have UpRev. Which I think I might go ahead and do now next time I am in my ECU... then I can just de-pin terminal 122 without cutting the wire... to this day my cars wiring is all un-cut minus my injector sub-harness... prefer to keep it that way personally.

Attached Images

370zM107.gif (30.4 KB, 128 views)

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