BCM issues

[volvo4fun]

2004 XC70 with 285K.

My daughters have been complaining about the brakes not working right on this vehicle.

Ended up buying a VIDA Dice unit to help me diagnose. The codes I am getting are all over the place:
BCM-0130 - brake pressure sensor 1 too low
BCM-0136 - brake pressure sensors 1 & 2 signal outside its permitted range
BCM-011 - left front wheel sensor fault signal (got this ones fixed I think)
BCM-0012 - left front wheel sensor mechanical error (got this one fixed)
BCM-0050 - control module faulty signal

Their description of what was happening is not helpful at all, so finally I started taking test drives in the vehicle in the morning. As they said it only happened early in the morning.

Within a few hundred yards from leaving the driveway I hear a chattering sound in front of me. Either in the dash or in the engine compartment.
Through the brake pedal I feel pulses of about 1 per two seconds.
Seems like the car is dragging a little bit.

The ABS light comes on and the warning message is shown.

The sound and pulsing goes away by itself within 30 seconds and the car drives normally afterwards.

The brakes worked regardless.

Can VIDA provide different information from a moving vehicle while the problems begin?

Any other suggestions would be appreciated.

[SuperHerman]

I think VIDA will provide you more information. You need to move into another section of the program.

See this link, although for a different car and issue, it provides a frame work for how to navigate within VIDA.

http://forums.swedespeed.com/showthread ... -VIDA-DiCE

I have used VIDA in a similar manner for other issues. I would imagine that once you find the correct test mode you will be able to activate the various module(s)/parts involved.

Hopefully some one with actual experience with the BCM can chime in and provide additional information. For now follow the frame work in the link, but focus on the BCM.

Other than VIDA, how is your brake fluid level?

[chrism]

Each time you start up the car, the ABS will do a self test which occurs at about 15 MPH. It only does it once for each time you start the car. It won't do it again until the next time you start the car and accelerate to the ~15 MPH. The self test is normally slightly audible as a "click" noise. It might be that yours is getting hung up in that self test. What you do to remedy the problem is better addressed by someone that has experienced the same issue.

[volvo4fun]

@Super.... thanks I will review the information and report back what I learned

I drove the vehicle again for about 2.5 hours over the weekend.
On the way to my destination I felt the pulsations but no lights come on.
On the return trip, I started the car but did not immediately drive away. All the lights came on sitting there, including brake failure, pull over safely.
When I drive away the brakes functioned normally.
At the end of the drive way I stopped the car, and pulled the key, then restarted ==> no lights, nothing at all.

[chrism]

If it comes down to the BCM, Xemodex apparently repairs them.

https://xemodex.com/us/product/brake-co ... 456-10-20/