Reflashing Toyota ECUs back in 2005

Reflashing in the early days

In 2005, Toyota promised “an era of unprecedented cooperation with independent repair shops”. Part of this new philosophy is providing access to all of the tools and information available to dealership mechanics to independent mechanics.

Information in the form of repair manuals, technical service bulletins, campaigns, and even Toyota’s dealer training programs can be accessed through Toyota’s TIS website. Special tools and software can also be ordered through TIS.

Toyota TIS webpage screen

Reprogramming the ECU (engine control unit) is one of the repairs we’ve had to send to a dealer in the past. Without the software and the tool to do the reprogramming, an independent, no matter how well trained, can not do an ECU update.

Thanks to Toyota’s excellent new attitude, we’ve been able to buy the factory scan tool and software and we can install ECU updates here at Art’s Automotive! This is a Rav4 that had a check engine light and a code P0420 (catalyst efficiency code). There was not a problem with the catalytic converter, the computer was simply being over-critical in it’s analysis of the converter’s performance.

Toyota realized there was a problem, rewrote the monitoring software, had it approved by the US EPA and the California Air Resources Board, then made it available to dealers and independent shops via download or CD. Failing to follow the reprograming instructions carefully can make a paperweight of a $800 computer, so it’s not a job for impatient mechanics or Toyota novices.

MasterTech scantool screen showing reflashing progress

Having the factory scan tool also provides access to more information and testing capabilities than are available using a generic OBDII scanner. OBDII is a specification for access to diagnostic information from the ECU. All manufacturers must meet the minimum requirements of the OBDII specification. However, manufacturers also add proprietary diagnostic capabilities to their computer control systems that are accessible only with the factory scanner.

Toyota’s willingness to sell the scanner and software to us has made our job a lot easier. Systems inaccessible with a generic scanner, like SRS (air bag), ABS (anti-lock brakes), and many others can be inspected using the MasterTech. There are also many bi-directional tests that can be performed to quickly check system operation without disassembly and hands on inspection. Anything that saves time while paying for by-the-hour diagnosis makes everyone happy.

2011 note: we wouldn’t use the Mastertech for this procedure these days. We use the laptop-based Toyota Techstream for all software updates and diagnostic work.