Introduction to J2534 and Flash Reprogramming Edited and reposted from Drew Technologies autoboss v30

The days of diagnosing and eobd2 repairing automobiles without a laptop are fading. Newer vehicles have large number of onboard computers, each dedicated to performing specific tasks. Common onboard computers in newer vehicles include the Engine Control Module (ECM), Transmission Control Module (TCM), Fuel Injection Control Module (FICM), Anti-lock Brake System (ABS), Body Control Module (BCM) and numerous other control modules to manage every electronic system integrated into the vehicle.
Each onboard OBDII Circuit Board computer is programmed at the factory with software enabling it to perform certain tasks. Inside the ECM is software containing hundreds or even thousands of parameters to control spark, fuel, cruising, emissions, idle, economy, drivability, and performance. Similarly, a TCM will have software to control how the transmission and torque converter function. Sometimes, after the vehicle is shipped from the automaker, updates are released to improve emissions, fuel economy, drivability, performance, or specific bugs in the original software that have caused warranty issues. Updating this software autoboss v30 can be a proactive fix because often it will resolve problems that a customer hasn't reported or noticed yet...
The practice of updating software in these modules is more commonly known as flash reprogramming. At new car dealerships, flash reprogramming is a relatively straightforward process because service technicians are connected to the automaker and have the expensive, specialized tools dedicated to reprogramming. The independent repair shops have faced a more difficult challenge because most shops typically service more than one make of automobiles. This increases the complexity, cost, and training required to operate dozens of different factory service tools.