ELM327 v2.3

OBD to RS232 Interpreter – firmware version 2.3

Quantity Pricing

The following are the unit prices, as you vary the quantity purchased:






All prices are in Canadian dollars. We use the total number of v2.3 ICs purchased (ELM327P + ELM327SM) for the calculation.


Almost all of the automobiles produced today are required, by law, to provide an interface for the connection of diagnostic test equipment. The data transfer on these interfaces follow several standards, but none of them are directly usable by PCs or smart devices. The ELM327 is designed to act as a bridge between these On-Board Diagnostics (OBD) ports and a standard serial interface.

In addition to being able to automatically detect and interpret nine OBD protocols, the ELM327 also provides support for high speed communications, a low power sleep mode, and the J1939 truck and bus standard. It is also completely customizable, should you wish to alter it to more closely suit your needs.

The data sheet discusses all of the ELM327’s features in detail, how to use it and configure it, as well as providing some background information on the protocols that are supported. There are also schematic diagrams and tips to help you to interface to microprocessors, construct a basic scan tool, and to use the low power mode.

If you are wondering what the differences are between the many ELM327 versions, you may find the Version History section in Help / OBD / Tips to be helpful.


  • Diagnostic trouble code readers
  • Automotive scan tools
  • Teaching aids


  • Power Control with standby mode
  • Universal serial (RS232) interface
  • Automatically searches for protocols
  • Fully configurable with AT commands
  • Low power CMOS design

Connection Diagram

( PDIP or SOIC, top view )
ELM327 connection diagram

Block Diagram

ELM327 block diagram


The ELM327 data sheet (ver L, 439K):
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A list of the AT Commands that are supported by this version (209K):
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The Programmable Parameters that are supported by this version (78K):
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ELM327 Version History

Although this is provided in the data sheet, many people still write to ask what the differences are between the versions. To help with this, we also provide a summary of the Version History in the OBD Help section.

Alternative Labelling

To help us meet demand, Microchip Technology has been programming and labelling some of the ELM327 chips for us. These ICs may look different, but are functionally identical. You may receive ICs that look like those shown above, or as shown below. The differences are only in appearance:

sku: ELM327P sku: ELM327SM sku: ELM327SM

Related Products

The following product may also be of interest to you:

And you may find it convenient to order CAN transceivers from us:

The following offer only specific OBD protocols: