i have a hyundai matrix with kefico ecu .

the problem is that when the car is cold the engine starts. after a while engine do not start again.
someone program again the key and the same problem.
check engine lamp off when car starts.
dtc problems in memory was throttle and camshaft , both was check and was ok, after it does not start there is no dtc stored.

when the car do not starts ,there is no signal at ignition , injector and fuell pump

ecu is bosch kefico with memory 29f400 ,tms374 .

technician (key) says than is often problem and sometimes ecu is overvoltage and not recognises key data.

we do not know aboul alarm if cuts fuell, ignition.......


any suggestions to check what is wrong ? ecu or a signal
?