Volvo FM 9: Addressing the 'Stop brake system failure' Message and the Role of Ad-blue

Tells you to check the brakes.
Go to diagnostics from the dashboard and read what the "Brake System" says.

Most often, this message is displayed in the case of wear / difference between the left and right side of the brake pads, damage to the wear sensors, ABS sensors.

The message itself does not say much. There may be many reasons for this. As long as you do not read the faults (and the codes provided with them), there is no way to help you.

Buddy ..... no matter how much you write, without entering the codes, your further writing does not make sense. Read the codes it will make any diagnosis easier.

Marioo1977 wrote:

The car was at the mechanic's and they took out the muffler, there were literally rocks ... which had to be chained

He is a weak mechanic, seeing a brake fault and doing a silencer.

Marioo1977 wrote:

Sensor breke pedal Data erratic ... Mid 136 Sid 76 FMI 2 ..... and the second Data link Mid 144 Mech or el fault Active some magician today came to the mechanic and read on the computer that this is the main valve of the brake pedal, how do you think? ??

The most real fault. The brake valve (under the pedal) is not only pneumatics. There are also two potentiometers that read the position of the pedal.

Separately, it is probably impossible to buy (maybe something has changed), the entire valve remains to be replaced.
And don't allow any half measures. Brakes are essential

One piece of advice: change the mechanic. Because personally, I would be afraid to give him a rake, because it would probably spoil it.

Hello after the "forced" break, heh. I do not see the need to fly experts. Emergency brake mode is exactly what is displayed in English. There is also a red triangle. Then the ABS system fault will be written. And further, depending on what the controller deems right, the same repair of the fault may not be enough, because there are various additional steps to take the brake electronics out of the emergency mode. Ie. the system does not work although it has already been repaired. Most often, the so-called "Reset test: brake pedal activation" (to be found on the forum), which must be done very carefully for various reasons. And so, for example, the reset test must be accepted by the controller, which will signal it with about three times the modulators self-test, so first of all the brake pedal must be functional, because the controller, seeing the threat, will of course reject it with an appropriate error code. You still have to be sure that the fault is fixed, otherwise the system will go back to safe mode just as it wants, not knowing when to start all over again. It is also important that a certain group of errors, being repaired, brings them out of the emergency immediately. How it behaves then, you can successfully check it by making an attempt such as detaching and reconnecting the brake pedal sensor cube, the triangle will go out in the eyes. Their division into requiring and not requiring activation in emergency brake mode is not fully known to me, although it is explained extensively in the Volvo documentation. I presume that such a list is not prepared intentionally to read the instructions, because brakes are the basis of driving. Maybe someone knows, he will show it off. In addition, it is important to distinguish between the message on the clocks informing about the emergency mode of the anti-skid system and the message about the emergency mode of the brakes, because these are two fundamentally different failures including their consequences!

Welcome back. I have such a request for you at this point. If there are a lot of time and patience for the emergency brake mode here, I invite you to an in-depth analysis of the fault, because I just found out about the ambiguities in the repair instructions and public knowledge about it. It would be good to talk about it on the occasion of FMI 14 like here Link , but unfortunately the topic is closed with a demanding attitude in getting rid of the problem temporarily. The point is that when an emergency mode of the brakes is reported and a suspect component is functionally turned off with an error, then there is also the possibility of seriously impaired computer diagnosis of the brakes something like an electronic (i.e. very similar to immo in the French) active component lock, about which no the manual I know so far does not even mention it. It looks exactly as if the manufacturer did not agree to the measurement of damage via OBD (what a simplicity!), And therefore the impossibility of activating the pedal until it is repaired / replaced with a working one, the only way to obtain information about the fact remains only in the sphere of extremely time-consuming analysis (qwa have!) drawn conclusions !!! I figured it out after a heavy pneumatic failure on a really neglected tractor with a compressor failure - such as in the link. I would like to mention that by investigating the stubborn topic (the reason for ignorance), I came to the trial and error method that there is an update of the driver software that eliminates the defect of signaling (i.e. on the board) activation and deactivation of this lock, because I turned off this possibility in a tractor serviced by Galaauto, where it has been updated with the so-called crap. slot machine. I encourage you to take the tests, or finally a request for teaching help in this direction.