So, since the warnings are still there what would the next step be? The voltages a a little higher than you stated. Do we need to bring them down more and how would that be achieved? Thank you. I tried to PM you but didn’t know if it went through. It’s probably better here so others can see what has been done too.

 

I just measured mine; using the chassis as the ground and got almost identical voltages: 3.08 and 2.52. It seems like your circuit is correct and functional.

I wonder if that second sensor is the issue. Does anyone know what the second vacuum booster sensor on the '07 is called, what it does, or a part number?

It could also be possible that the earlier EBCMs needed a greater voltage drop when pushing the brake pedal? You could replace your circuit with a radial potentiometer: https://a.co/d/8WEO1ev

You could use the potentiometer to manually vary the voltage drop when you push the brake pedal.

 

Took these pictures today... let me know if you need any other pictures:






Oh, I was also curious to when the "Service Brakes Soon" message appears? Does it appear shortly after starting the engine, or after you push the brake pedal for the first time? It is important to not push the brake pedal when starting the engine to determine this. If the message appears after starting, but before you push the brake pedal, then your initial voltage (3.08 volts) is either too low or too high. If the message does not appear until after you push the brake pedal, then your initial voltage is good, and you just need to adjust your voltage drop up or down.

Of course, if that second booster sensor is the issue, then testing for when the message appears may not be very fruitful.

 

I get the service brake warning as soon as a start it. If I clear it and start in motion I get stabilatrac and traction control within about 20’ of motion. I’m pmed pictures of the other sensor. I did try connecting the 2 wires and it did not help. Thank you.

 

The second sensor is on the top right looking at the picture.

 

I'm not sure what that sensor is measuring, but if it is only a 2-wire, you might just measure the resistance of the sensor and replace the sensor with a resistor of the same value.

 

Thank you, I’ll try that v