Known problems with china clones of ELM327
Posted: Thu Jul 16, 2015 5:03 pm
Here we try to accumulate and analyse known problems with china clones of ELM327.
Just to clarify, 99% of devices sold as ELM327 are counterfeit clones. The only question is quality of clone. First USB clone we purchased in 2011 for $25 had very good quality. Clones purchased 1-1.5 years ago and earlier have bad quality. Many of clones sold in 2015 have nothing to do with ELM327 except the brand itself.
Known problems:
#1. Adapters reported as ELM327 v2.1. Main chip doesn't support a half of original ELM327 commands and logic. Discussion thread:
http://forscan.org/forum/viewtopic.php?f=4&t=22#p840
Everyone can make sure using a terminal and sending some commands:
This problem may exist in adapters of any type (USB, BT, WiFi)
Update 2015-09-15:
It seems the people who developed this piece of bugs have changed version from v2.1 to v1.5. So new adapter behaves the same, but returns v1.5 instead of v2.1. Also some missing commands are not the most painful problem of this adapter. Main problem is that is has very simplified and incorrect functionality comparing to original ELM327. For example, it is optimized for OBDII communication. OBDII commands are usually 2 bytes long as maximum. So the adapter doesn't read more than 2 bytes from the command string. FORScan uses service protocols that may send much more. So if FORScan tries to send, for example, 3 bytes to a module, the adapter sends only 2 of them (3rd byte is either not sent or filled with zeros). As a result, module doesn't respond or returns error instead of expected answer.
#2. Adapter is not able to process requests that return a lot of data. It simply freezes. Main chip seems to be OK (fair clone). Discussion:
http://forscan.org/forum/viewtopic.php?f=4&t=1531
This problem exists in Bluetooth devices only.
#3. Adapter is reported as v1.5, but doesn't support a half of commands of original ELM327 set (but not the same set as in case #1 described above - seems to be another clone development).
Everyone can make sure using a terminal and sending some commands:
Just to clarify, 99% of devices sold as ELM327 are counterfeit clones. The only question is quality of clone. First USB clone we purchased in 2011 for $25 had very good quality. Clones purchased 1-1.5 years ago and earlier have bad quality. Many of clones sold in 2015 have nothing to do with ELM327 except the brand itself.
Known problems:
#1. Adapters reported as ELM327 v2.1. Main chip doesn't support a half of original ELM327 commands and logic. Discussion thread:
http://forscan.org/forum/viewtopic.php?f=4&t=22#p840
Everyone can make sure using a terminal and sending some commands:
Commands answered with '?' are unknown for this adapter. Although normal ELM327 should recognize them (API specification can be found on http://elmelectronics.com/)>ATI
ELM327 v2.1
>ATPP2ASV38
?
>ATE0
OK
>ATL0
OK
>ATH0
OK
>ATR1
?
This problem may exist in adapters of any type (USB, BT, WiFi)
Update 2015-09-15:
It seems the people who developed this piece of bugs have changed version from v2.1 to v1.5. So new adapter behaves the same, but returns v1.5 instead of v2.1. Also some missing commands are not the most painful problem of this adapter. Main problem is that is has very simplified and incorrect functionality comparing to original ELM327. For example, it is optimized for OBDII communication. OBDII commands are usually 2 bytes long as maximum. So the adapter doesn't read more than 2 bytes from the command string. FORScan uses service protocols that may send much more. So if FORScan tries to send, for example, 3 bytes to a module, the adapter sends only 2 of them (3rd byte is either not sent or filled with zeros). As a result, module doesn't respond or returns error instead of expected answer.
#2. Adapter is not able to process requests that return a lot of data. It simply freezes. Main chip seems to be OK (fair clone). Discussion:
http://forscan.org/forum/viewtopic.php?f=4&t=1531
This problem exists in Bluetooth devices only.
#3. Adapter is reported as v1.5, but doesn't support a half of commands of original ELM327 set (but not the same set as in case #1 described above - seems to be another clone development).
Everyone can make sure using a terminal and sending some commands:
Commands answered with '?' are unknown for this adapter. Although normal ELM327 should recognize them (API specification can be found on http://elmelectronics.com/)>ATI
ELM327 v1.5
>ATPPS
?
>ATI
ELM327 v1.5
>ATPP2ASV38
?
>ATE0
OK
>ATL0
OK
>ATH0
OK
>ATR1
?
>ATST32
?
>ATS0
?
>ATAT1
?
>ATCF700
?
>ATCMF00
?
>ATI
ELM327 v1.5