My mom wants to know something.Does a computer box on a Mazda have anything to do w/ it starting & cuting off?
Year:2000
Model:Prozeda XL

When you sometimes cut it off, it wo not start & sometimes it cuts off in the middle of the road.

Yes, it does. Generally known as the Powertrain Control Module, or P.C.M. But it is usually not the source of a no-start trouble. l would check for fuel and spark first. Be sure to include the year, make, and model of the vehicle for future questions.

It could. The ECM usually controls the fuel injection and ignition system.

It is just my guess, but l think there is a loose connector some where. Think back about what work has been done (fuel pump, cam belt & such) this may give u a clue as to where to look.
Also it could just be a bad ignition switch, being Pro Mazda, l hate to admit that l have problems with one in mine. l have also heard of others that have experienced the same thing. But mine has never cut out driving down the road.
Off the wall, but something cheap to replace that may be causing this problem may be the fuel filter. If u do not know that it has been replaced in the past 30000 miles, just do it. Because this could be causing the problem & will lead to a bad fuel pump in time.

The computer does control engine functions, however sometimes the ignition system has a separate module of it is own that can cause this problem. Parts for this vechile r expensive & non-returnable if installed.Save yourself time & money by taking ur car to a qualified tech who can troubleshoot this problem for you. the most expensive thing in fixing a vechile is guessing at the problem & throwing parts at it. Always ask for a written estimate before repairs r made & never be afraid to ask for a second opinion.

nice question.. this is more complex to explain that u might think

the ecu or computer box has to do with both things but at the same time it not have to do.. explanation

with no ecu car will not start. why because when u hit the key to start the engine first u activated the acc & the main unit so the ecu will switch on, the starter will rotate the engine & the ecu detect the engine is spinning & then it starts to work sending fuel & activate the ignition to start the engine that is why when u hit the key the car will not start inmediately, the engine spins a few times then start

and for the cuting off... well.. when u hit the key to turn off the car the ecu dont shut down the fuel & ignition.. the switch itself shut down the ignition, ecu detect no ignition power & then it stops from sending fuel

so the start up is like a warm up for the ecu, it checks everything is ready for start but when shut down the key will shut down the engine & ecu will shutdown it self when it detects no ignition power

it has many other details for complete the explanation but for now is all u have to know