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The days of diagnosing and repairing automobiles without a laptop beside you are quickly fading. Newer vehicles include a large number of onboard computers that are each dedicated to performing specific tasks. Common onboard computers in newer vehicle 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 from power door locks to crash data.

Each onboard 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, idle, cruising, emissions, economy, drivability, and performance. Likewise, 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 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 relatively straight forward because service technicians are connected to the automaker and have the expensive, specialized dealer service 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.

J2534 – A Solution Arrives In 2000, the Environmental Protection Agency had been watching this issue and decided to take action. The EPA requested a standard be developed within the SAE that led to

Show Desktop.scf J2534, a mandated specification to which automakers who sell vehicles in the United States must conform. The original J2534 specification was later updated to J2534-1 in order to support all automakers. The EPA mandate requires automakers to support aftermarket repair shops with J2534-1 flash reprogramming for any emissions related computer modules on a vehicle that can be reprogrammed by a new car dealership. This mandate took effect for all 2004 and newer vehicles, but many automakers have decided to offer J2534-1 support for vehicles older than 2004 and some vehicles as early as model year1996.

J2534-1 is a system devised of two independent parts: subscription software and a J2534- 1 compliant PassThru vehicle interface. The subscription software comes directly from

Drew Technologies, Copyright 2009


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