Installation

Under-the-dash (UTD) vs. under-the-hood (UTH) and their respective pinouts

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.

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.

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.

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.

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.

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