Motec Brake Pressure sensor

I'm currently adding a Honeywell 2000psi sensor to a car I'm working on the car is currently using a M150 ECU and I want to be able to trigger the brake lights using brake pressure from the Honeywell 2000psi sensors. Is it possible to wire the brake lights to the ECU and have it trigger the ground side of a relay to trigger the brake lights by using the brake pressure sensor? I've searched the internet on how to trigger brake lights with motec and it having problems finding any answers.

Hi Josh,

Do you only have the M150 in the vehicle, or another MoTeC device?

Most vehicles that I wire the brake lights have a separate circuit that is supplied switched and fused BattV+ feed to a brake light switch (either in the hydraulic circuit or a switch on the pedal) that directly controls the brakes lights. This means that as long as the vehicle is powered, you have working brake lights. Some OEM's I have seen use a permanently powered circuit to the brake lights as well (I have a feeling that this may have been a requirement in vehicles for a period of time)

I put code in my M1 firmware to do this. You select the brake light resource and configure that. Since I know you don't have one of my firmware packages, Here is a method that I think will work -- If you connect your Brake Pressure sensor to two inputs, you can configure one as Brake Pressure Front (or Rear) Sensor, and the other can be selected as the resource for Auxiliary Output 5 Channel Sensor Resource. This channel can be used as the input to a Duty Cycle table, and can drive the Auxiliary Output 5 Resource. You can configure the duty cycle table for switch behavior by setting the Frequency to 0.

Another much easier way if you have a MoTeC Dash or PDM is to use an Aux Output in the dash to trigger the Brake Light Relay (the dash can get the data from the M1 Brake State channel), or if you have a PDM it can also use the "Brake State" to enable a Brake Light Output.

We are also running a Motec C125 Dash. We are possibly trying to view the front and rear brake PSI so we can visually see what our brake bias is currently at on the C125 dash while somehow being able to activate the brake lights I know its alot... Both the front and rear brake master cylinders are on a balance bar. The 16 Sti were working on is running the M150 on a patch harness and the car is using an obp pedal box.

You can attach your brake pressure sensors to either the M150 or C125 -- whichever has the most I/O available and is the easiest to wire. The Aux Out on the C125 is easier to setup for the brake relay control. I can provide a table for your C125 to calculate brake bias for display on the dash in real time (useful for setting the balance bar) either on grid / pitlane or in the paddock. This is very common for the race cars we support.

check out https://veracitydata.com for my contact info.