Pin | Signal | Description |
1 | TD | Engine rotation speed |
2 | CAN-High | CAN OBD-II diagnostic |
3 | CAN-Low | |
4 | Shielding | |
7 | Oil service and Inspection reset | |
11 | External starter turn on | may be N/C |
12 | Battery indicator | may be N/C |
14 | Battery power | +12V |
15 | ISO 9141-2 L Line | ISO 9141-2 RXD- Diagnostic Data link |
16 | Ignition +12V | KL.15 power |
17 | ISO 9141-2 K Line | may be n/c |
18 | PGSP | Programming line |
19 | GND | |
20 | ISO 9141-2 K Line | TXD - Diagnostic data link |
Pins 17 and 20 may be shorted in diagnostic cable.
Some OBD-II cables schemes:
OBD-2 ISO 9141-2 (14230-4, KWP2000) simple serial cable
OBD-2 J1850 PWM, J1850 VPW serial ELM327 cable