Paul-R wrote: ↑25 Apr 2018, 18:39
Marc, you say that the EPB has a defined lifetime use and the number of applications is counted up. Where is the count stored? Is there a procedure to reset this to zero? Does fitting a brand new EPB unit automatically reset the counter to zero?
It seems daft that even if the EPB is still working properly that after a certain number of applications it would cease to work. I can accept that it would throw up an EML or error message but does it also mean that the BSI (or whatever) would then disallow the car to be driven. Equally driving, and thereby parking, without a parking brake could also be a problematic experience.
Ok, so the system incorporated in the X7 is made by Continental Teves.
Diagbox can read the number of handbrake 'Application / Release Cycles' that have been carried out. There are 2 readings actually, one for the normal application and one for application at maximum force.
The system is designed to operate for
16,777,214 application cycles (very specific, don't you think?) of either normal or maximum application. (so no need to panic just yet
)
There is no reset Paul - when a new EPB is installed, it must be configured and I suspect that the count information is stored directly in the EPB ECU, which is non-removable from the internal part of the EPB unit.
There are 36 possible specific fault codes returned by the system and it seems to be a very detailed and complex system. So even with some of the automatic functions inoperative the system can still be activated manually.
So no, the BSI would not stop the car or prevent the handbrake from operating whilst it is able to still do so. The counter is really for diagnostic checks and to determine how many cycles have been used in determining any faults - but anything that does fail in the unit like the sensors or actuators will necessitate a complete replacement unit. But it is encouraging at least with that duty cycle figure at least!
It's nice to have a good margin!