J-2534: 2015 update

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J-2534: 2015 update

Craig Truglia is an ASE A6, A8 and L1 certified technician who presently works as a service writer for Patterson Auto Body, a repair facility in Patterson, N.Y. A former shop owner and editor of several automotive repair magazines, Truglia combines his Columbia University education with the real-world experience he sees daily in the automotive repair field. Technicians Truglia and Fred Byron took part in diagnosing the different vehicles presented as examples in this article.

Reflashing is no longer something new and neither is getting the job done with a J-2534-2 tool. By now many shops have decided that they are in it to win it or they simply sublet the work. Some shops are still not sure if they should get into it. Auto Service Professional previously published a few different articles on J-2534 reflashing, archived on our website at, that already cover a lot of the bare basics of reflashing. It is wise to review these first before continuing with this article. Here we build upon those previous articles, so that what is covered here are updates that hopefully will keep technicians abreast with changes in J-2534 in recent years.

What to do about Windows 8

We can sum up this whole section in one sentence: Don’t use a laptop with Windows 8.

It is a shame, really, that Windows 8 offers no real benefits over Windows 7 other than “apps” and the use of a touch screen. However, these things do not help us with reflashing.

In our first article on reflashing, the advice at the time was to use Windows XP when possible and if one had Windows 7, to use the compatibility mode. Now as years passed, the OEMs finally began updating their programs so that they worked with Windows 7. Therefore, the advice offered in the past is now outdated, because technology moves so quickly!

Windows 8 has been out since 2012, so one would think by now that the OEMs would update their programs to work with the program. Many haven’t. One notable exception is Chrysler (see Figure 1.)

However, the J-2534 Toolbox 3 software from Drew Tech, one of the key providers of J-2534 reflashing hardware, does not work with Windows 8 as of the writing of this article. According to Drew Technologies, their equipment “supports Windows 2000, XP, Vista (32/64-bit) and Windows 7 (32/64-bit). Windows XP or Windows 7 32-bit are recommended for compatibility with OEM applications. Currently, we recommend avoiding Windows 8.”


There are tutorials online on how to supposedly make a Windows 8 laptop functionally a Windows 7 laptop. There is also a way to open up applications using “previous versions of Windows” on Windows 8. It is recommended here to avoid doing this. Windows 8 simply does not have the same compatibility as Windows 7, and even if the program appears to start working, the only way the technician knows everything is good is when the reflash is done.

Why risk killing a module when it is unknown at present whether Windows 8 is up-to-snuff? The best advice for now is to avoid it.

J-2534 quick review

As always, keep in mind the following essential tidbits when reflashing a vehicle.

Make sure the battery is fully charged and there isn’t excessive corrosion on the battery terminals.

Be sure to have a battery maintainer, though many OEMs such as Honda still only require a battery pack on the battery. If the reflash fails, don’t turn the key onto the off position. Instead, keep reflashing the same module until it works or there is a risk of permanently ruining the module. On older GMs, this may include unplugging modules (or the fuses leading to them) that are not being reflashed.

Lastly, be sure to have any applications updating in the background of your PC turned off and have all wires properly plugged in so no connections or power is lost during the reflash.

Honda’s J-2534 program

For those with the Honda MVCI (available from OTC), they can download the HDS software (the Honda Factory Scan Tool) for $10 for a one-day subscription. At website the free J-2534 program can be downloaded by clicking on the link at the bottom right of the page (see Figure 2). Further, the HDS subscription is extremely reasonable in price. Even more “reasonable” is Honda’s J-2534 program, because it is completely free of charge. It only reflashes PCMs (for reasons pertaining to federal emissions standards), but this may be necessary to turn off Check Engine Lights and such.

On a 2004 Honda Accord, we had a vehicle with a high idle and hard shifting. This issue can become so pronounced it can set a P0507. It is wise not to reflash a vehicle unless a TSB confirms that its symptoms can be repaired by the updated software.

As seen in Figure 3, Mitchell ProDemand provides us with TSB 06-040 that informs us that in order to deal with this issue on the Honda, a PCM reflash is necessary.

The first step in repairing the vehicle was downloading the Honda program (see Figure 4). It is wise to continually get a new copy of the program, because the PCM updates are downloaded with the program itself (see Figure 5).


After downloading and starting the program (which will be in the Start menu), the technician has to pick his device. The Ease Universal Reprogrammer II is our weapon of choice on this Honda (see Figure 6). After clicking start, simply follow the directions on the screen. The program asks the technician to make sure the battery is good (see Figure 7). When one continues through the program, it automatically checks to see if the PCM is out-of-date (this 2004 Honda Accord’s PCM needed an update). If it is, it automatically chooses the update for the technician to put on the PCM (see Figure 8).

Before starting, the program gives the technician good advice to follow on any vehicle.

The long and short of it is, if the reflash fails for whatever reason, keep restarting it until it works. Honda says that the technician shouldn’t be afraid to restart the computer if necessary, but this should be avoided if at all possible.

Honda provides us a pretty good list of warnings that technicians should keep in mind when reflashing (see Figure 9). The last warning Honda gives is not to turn the key off in the middle of the reflash. This Honda took about 20 minutes to finish the reflash. It is not a quick process (see Figure 10).

Hopefully, when the OEMs finally get around to revamping their J-2534 programs, they emulate what Honda has done.

It’s foolproof and it’s free, you can’t beat that.   ‚óŹ

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