ElmScan 5 Compact is a “Clone”

Some months ago in October 2009, we had a news items that contained an item about the release of the new ElmScan 5 Compact from Scantool.net. At the time, we were in contact with Scantool.net and asked them if we would need to make any changes to OBD 2007. We received a reply that stated "You don't need to make any changes to OBD 2007. It works with ElmScan 5 Compact out of the box". On receiving that advice, we announced that OBD 2007 now supported the ElmScan 5 Compact.

Only in the last couple of weeks, have we discovered that the ElmScan 5 Compact does not contain an Elm327 v1.3, but is powered by a clone chip.

The brand name ElmScan 5 has always been synonymous with Elm327 chips since Scantool.net released their first ElmScan 5 scan tool, so we naturally assumed that when Scantool.net discontinued their ElmScan 5 USB, Bluetooth and Serial models, they were just consolidating their scan tool range with the one compact unit which did away with the need for the cable between the scan tool and the DLC connector of the vehicle. Unfortunately, we never contemplated that they may have swapped to a clone chip.

Even more remarkable, Scantool.net has been extremely vocal on many automotive forums, championing the cause about the use of these illegal Chinese clones. Their aim was to stress to the OBDII scan tool community, that the cheap scan tools available on eBay contained Chinese clones of the Elm327 chip and should be avoided at all costs. They even started a thread on their own forum in June 2007 with the heading “Why you shouldn’t buy an Elm327 Clone”. That thread has been read by nearly 25,000 readers, so I presume most readers here are very well aware of the term “clone”.

It was only when we noticed some of support logs on the Scantool.net forum that are sent by Scantool.net customers, at the request of the Scantool.net support staff, that we started noticing odd differences between their now discontinued models and the new ElmScan 5 Compact. We then studied a couple of our OBD 2007’s diagnostic logs from an ElmScan 5 Compact and got identical results. The following are the results of some of the AT commands sent to both an ElmScan 5 USB and the new ElmScan 5 Compact.

ElmScan 5 USB, ElmScan 5 and ElmScan 5 Bluetooth (all now discontinued)
Command Response
ATI Elm327 v1.3a
AT@2 123456789012 e.g. a serial number – 12 characters or empty string if not set
ElmScan 5 Compact (released October 2009)
ATI Elm327 v1.3a
AT@1 OBDII to RS232 Interpreter
AT@2 SCANTOOL.NET – 12 characters

The giveaway is the response to the AT@1 command, known as the display device description command as per the Elm327 datasheet. The default factory response to AT@1 is “OBDII to RS232 Interpreter”, so consequently every clone chip responds with that response.

The reputable scan tool manufacturers, who purchase Elm327 chips from Elm Electronics, are offered custom code to modify the AT@1 response, so that they can identify their product through code. Most manufacturers choose to display their company name, hence the discontinued ElmScan 5s responded with “SCANTOOL.NET LLC”. OBDII software such as OBD 2007 could then identify the scan tool that OBD 2007 was connected to. There are many legitimate uses of this string, one of which is used to restrict access of certain products to only work with particular scan tools.

So the clone manufacturers are stuck with “OBDII to RS232 Interpreter”. However that suited the Chinese cloners’ just fine. Let’s face it, if you are stealing some else’s work you are not likely to want to advertise who you are, even if hidden away in China. To counter that problem, Elm Electronics introduced two new commands in the 1.3 version of their chip, AT@2 and AT@3. AT@2 displays a 12 character string, as set by the AT@3 command. The logic behind the AT@2 command was to allow the scan tool manufacturer to display further information about their device such as a serial number, product code or production date etc. Basically anything that would help the scan tool manufacturer further identify their product. The only limitation is there is a limit of 12 ASCII characters that can be displayed. No custom code from Elm Electronics is required to set the 12 characters.

As Scantool.net no longer have the custom software option available to them to write the AT@1 response they are forced to compromise and use AT@3 to write their company name for the AT@2 response, albeit now limited to 12 characters. They obviously use this string in their own software to prevent their software from working with other scan tools. There was an embarrassing incident on their forum when a user who had just purchased an ElmScan 5 Compact complained, that Scantool.net’s own software refused to connect to his vehicle, because the software claimed that his newly purchased ElmScan 5 Compact was a clone. Quite ironical, when you consider how correct that was.

As a company we have decided to no longer recommend Scantool.net products, as we have no wish to be associated with any company that blatantly steals another company’s product. We suspect the other software companies presently associated with Scantool.net will most likely also withdraw their support.

We have checked with Elm Electronics and they have confirmed that Scantool.net now only occasionally purchase small quantities of Elm327 chips, most likely for warranty work for the now discontinued ElmScan 5 models. Scantool.net also confirmed that they no longer purchase from Elm Electronics, but didn’t offer to reveal their new source.

We have no wish to penalize any user of OBD 2007 who has purchased a Scantool.net product. If we were gullible enough to be duped, we can hardly blame our users for also being duped, and therefore we will not prevent our products working with either the ElmScan 5 Compact or their OBDLink scan tool now or in the future. However we will now withdraw all recommendations for any product from Scantool.net.