User's Manual

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.

SAE J2534 is a standard devised of two independent parts: subscription

software and a J2534 compliant Pass Thru vehicle interface. The

subscription software comes directly from the automaker, runs on your

shop PC or laptop, and can either be web-based or CD-based. The

subscription fees are charged differently for each automaker.

1.3 Pass-Thru Vehicle Interface

The second part of the system is a SAE J2534 compliant Pass-Thru

vehicle interface. This device acts as a gateway between the vehicle’s

onboard computers and the technician’s personal computer. It translates

messages from the PC into the protocols used by the automobile and

vice versa.

Performing J2534 reprogramming requires computer knowledge and

experience. The technician will need to operate a laptop or desktop, the

Pass-Thru device, and the reprogramming software. Operation will also

require a good high-speed connection to the Internet such as DSL, Cable,

or T1.