What is Car ECU reflash?

ECU stands for "engine control unit." It's the program that reads things like 02 and CO2 sensor output, engine rpm and controls engine performance by making inputs to the variable valve timing, fuel to air ratio, and the like.

How does ECU it work?

The computer "chip" that is the heart of the vehicle computer is commonly an EEPROM -- an Electronically Erasable Programmable Read Only Memory chip. The Read Only part of that means the chip retains its decoding without periodic electric refreshing; loss of chipped power doesnt lead to the chip losing its decoding (It's like the CMOS BIOS of a computer).

Why reflash?

"Flashing" the chip involves electronically erasing the read only program and replacing it with new, updated information (the engine control 'map'). Typically, when an vehicle computer is flashed, a new map is decked that allows the engine to handle 'hotter,' providing more Horsepower, altered valve timing, etc. This often makes the motor vehicle faster, but can decrease its credibility and durability.

Why locksmith?

In some vehicles (Toyota/Acura/Honda/Ford and few more) depends on model and year, when a driver lose all the keys to the car, there is no interface to deal with the situation and the ECU needs to be reflashed to accept a new set of keys.