Reset Master Cylinder Pressure Sensor Zero


New member
  • I moved to Maine about 5 weeks ago and bought my first Subaru from out of Georgia before I came. The car needed some work, but it is finally running good and on the road. When I bought it, the brake light was flashing with a solid lit traction control light. It was assumed that it happened after the battery died and a new battery was installed. I hooked up my scan tool and saw that the Master Cylinder Pressure Sensor was reading 3 bar. and that was causing my code, C0074. My scan tool cannot reset it. I can reset the lateral g sensor, steering angle, but cannot reset the Master Cylinder Pressure Sensor on my tool. I found an Autel MP808 does it, but they are $700., which I cannot spend right now.
  • I am attaching the TSB for this issue, which sounds kind of common, maybe that will make it easier to understand what I am trying to do in case I am confusing things.
  • I also dug deeper and along with the C0074 Master Cylinder Pressure Sensor Zero code, I have a B0202 code for the Integrated Unit that describes the code as CAN-HS counter abnormal, and CAN-HS bus off. I also have a U1202 code in the CAN System that is also described as CAN-HS bus off. Here is where I wonder of this is all connected. In the CAN System, it lists the fault location as Communication Line Failure (ECM/VDC/ABS to Unit), or Integrated Unit Failure.
  • Originally I ignored these thinking they only pertained to the Body Unit. But upon digging deeper, the Communication Line Failure got me to wondering if it may be my problem. My Master Cylinder Pressure Sensor reads 3 bar with no pedal input. It does function when the brake pedal is pressed, so it seems to be communicating. But, from what I read, the sensor is supposed to read and reset zero when the key is turned off.
  • Can anyone tell me if these are related, and point me in the right direction?
  • I moved to Maine, and need to get the car registered and it will need inspected immediately after that. I am told it cannot pass with the brake light flashing and VDC light steady.
  • Does anyone near the Jay/Auburn/Augusta area have a tool that can reset my Master Cylinder Pressure Sensor to see if it will clear up the blinking brake light and VDC?
Hope you guys can help, the temp tag ran out on the car and now my other car is down waiting for parts.


  • Service Bulletin.pdf
    638.2 KB · Views: 0

Latest posts