Power On Self Test in Automotive

[electronicsman]

I have this doubt generally in automotive field there are Power On self tests done like for example Memory test and other critical tests. But my doubt is this tests can fail during run time as well, then why specifically we do power on tests? Is there any specific reason attached to it? The probability of failure is more during power on?

 

[KlausST]

Hi,

What´s the alternative?
Doing memory test continously? .. And all other tests? like auto calibration routines...
..and what if the test has influence on the running system..because it modifies the values of memory cells (for sure at runtime they are filled with useful data), or just because it needs processing power.

For sure: everything is possible .. but does it improve overall functional reliability?
As so often: it has benefits, but also drawbacks.

Klaus

 

[electronicsman]

My other thinking for power on self tests is like if the vehicle is gone for maintenance and if the fault is rectified then he would do a power On off cycle to see if the faults are gone.

 

[wwfeldman]

passing power on self test means everything tested works (at least right now)
so its ok to start driving your car, or using your computer, or watching television, or ....
as opposed to the ... system isn't working, don't drive the car ... etc

clearly passing power on self test is important for the car
and in varying degrees, other things.

clearly its a safety issue