Bits and Bytes on J2534 Module Programming

Bits and Bytes on J2534 Module Programming

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Reprogram in my shop? Really?

Motor Age — Sometimes knowing “just a little bit” about something in today’s auto repair world is more than enough for me. I know just enough about automatic transmission rebuilding, for example, to know those jobs (for me personally anyway) are best left to a transmission specialist. Not so with other areas of our repair world.

Some technologies are so intertwined in the entire vehicle you really need to embrace that technology before it runs you over. Case in point: For more than 20 years, every technician performing electrical or drivability work has needed more than “just a little bit” of knowledge about standard electrical theory, proper Digital Volt-Ohm Meter (DVOM) usage and scan tool know-how. More recently, we can add oscilloscope testing and module programming to our required knowledge set. Maybe you’re reading this and thinking to yourself, “I’m fine with electrical theory, meter usage and scanner operation and I’m getting there on the scope but module programming? Come on! That’s for the new car dealer who has the factory scan tool!”

We all know that dealers and independents that are fortunate enough to own factory scan tools can perform various software programming and configuration procedures on Engine Control Modules (ECMs) on today’s vehicles. What many independent techs and shop owners don’t know is that most OEMs are migrating toward field programmable software for non-emissions-related modules. That list is extensive for some OEMs and includes everything from Body Control Modules (BCMs) to heating, ventilation and air conditioning (HVAC) heads.

Many of today’s service fixes are accomplished exclusively with software updates simply meaning that if you don’t do module programming — you don’t fix the vehicle, period. The generation for improvements to drivability, false DTCs, system performance, in car odors, false airbag deployments, even making parts last longer all through software updates has arrived.


Not that many years ago, modules either were replaced or had a pluggable chip replaced to update that module’s software. This wasn’t cost efficient for the OEMs to do under warranty so they evolved to programming electronically via Electronically Erasable Programmable Read Only Memory (EEPROM). Another factor in the increase of software updates/repairs is the sheer proliferation of electronics on the vehicle. Add it all up and you’ll find $8,000 worth of electronics, software and wiring in the average $20,000 vehicle.

Source: Motor Age

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About the Author

Nick Taylor

Nick Taylor is the SureTrack Community Administrator and a Senior Applications Specialist at Mitchell 1 with over 25 years of experience with electronic repair data systems. Nick previously worked in the automotive dismantling and engine rebuilding industries.