> For the complete documentation index, see [llms.txt](https://docs.macchina.cc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.macchina.cc/product-documentation/m2-docs/detailed-reference/installation.md).

# Installation

The Macchina M2 was designed to be modular to give you the option of many installation options. The under-the-dash (UTD) version plugs directly into the OBD2 port of any modern car. The under-the-hood (UTH) version can be spliced into a wire harness. A connector is the only difference between the 2 versions.

![](/files/-Lhg6EisiZsZhh4wrf1P)

## Under-the-Dash (UTD)

The "Under-the-Dash" version of the M2 plugs directly into the OBD2 port of the modern car. Any car built after 1996 has an OBD2 port near the steering wheel, under the dash.

![](/files/-Lhg6EiuvBasaMv_7MQI)

The OBD2 connector is a 16 pin connector that provides power and a data connection. The image below shows the pin orientation of this 16 pin connector.

![](/files/-Lhg6Eiw_jOWCfIVcUyi)

This following table describes the functionality of each pin.

| Pin | Schematic name | function                |
| --- | -------------- | ----------------------- |
| 1   | SWC\_BUS       | Single Wire CAN         |
| 2   | J1850+\_BUS    | J1850 + BUS             |
| 3   | MSC\_BUS+      | CAN1 HIGH               |
| 4   | CHASSIS        | CHASSIS GND             |
| 5   | DGND           | Digital GND             |
| 6   | HSC\_BUS+      | CAN0 HIGH               |
| 7   | 9141\_K\_BUS   | K-LINE or LIN channel 1 |
| 8   | TP2\_NET       | Test Point              |
| 9   | TP1\_NET       | Test Point              |
| 10  | J1850-\_BUS    | J1850 - BUS             |
| 11  | MSC\_BUS-      | CAN1 LOW                |
| 12  | TP3\_NET       | Test Point              |
| 13  | TP4\_NET       | Test Point              |
| 14  | HSC\_BUS-      | CAN0 LOW                |
| 15  | 9141\_L\_BUS   | L-LINE or LIN channel 2 |
| 16  | VIN            | +12V INPUT              |

## Under-the-Hood (UTH)

The "Under-the-Hood" version of the M2 is exactly the same as the "Under-the-Dash" version, but rather than a OBD2 connector, it uses a more general purpose connector. This connector takes the form of a 24-pin pluggable connector. Typical usage for this connector would be a more permanent installation where M2 would be hard-wired or spliced into an existing cable harness.

![](/files/-Lhg6EiyAf5P1nGSKfFO)

The image below shows the pin orientation of the 24 pin connector. Notice that the top row has the ODD pins and the bottom row has the EVEN pins.

![](/files/-Lhg6Ej-XbfC9pAZ6xHk)

This following table describes the functionality of each pin.

| Pin | Schematic name | function                |
| --- | -------------- | ----------------------- |
| 1   | TP1\_NET       | Test Point              |
| 2   | SWC\_BUS       | Single Wire CAN         |
| 3   | J1850-\_BUS    | J1850 - BUS             |
| 4   | J1850+\_BUS    | J1850 + BUS             |
| 5   | DGND           | Digital GND             |
| 6   | DGND           | Digital GND             |
| 7   | MSC\_BUS-      | CAN1 LOW                |
| 8   | MSC\_BUS+      | CAN1 HIGH               |
| 9   | DGND           | Digital GND             |
| 10  | DGND           | Digital GND             |
| 11  | TP3\_NET       | Test Point              |
| 12  | CHASSIS        | CHASSIS GND             |
| 13  | TP4\_NET       | Test Point              |
| 14  | DGND           | Digital GND             |
| 15  | DGND           | Digital GND             |
| 16  | DGND           | Digital GND             |
| 17  | DGND           | Digital GND             |
| 18  | DGND           | Digital GND             |
| 19  | HSC\_BUS-      | CAN0 LOW                |
| 20  | HSC\_BUS+      | CAN0 HIGH               |
| 21  | 9141\_L\_BUS   | L-LINE or LIN channel 2 |
| 22  | 9141\_K\_BUS   | K-LINE or LIN channel 1 |
| 23  | VIN            | +12V INPUT              |
| 24  | TP2\_NET       | Test Point              |