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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