Diagnostic connector
The Nissan Leaf is fitted with a Type A diagnostic connector as defined in ISO 15031-3 or its equivalent SAE J1962. Type A diagnostic connectors have 16 pins arranged in two rows of eight. Nine of the pins have a mandated designation - with use of the remaining pins being at the discretion of the vehicle manufacturer.
Location
The Leaf’s diagnostic connector is located beneath the steering column as is seen in Figure 1.
Figure 1 Nissan Leaf OBD-II vehicle diagnostic connector (mating-end view)
CAN buses
The Leaf has three CAN buses commonly referred to as: AV-CAN, EV-CAN, and Car-CAN. The CAN protocol used in the Leaf is ISO 15765-4 CAN (11-bit ID, 500 kBd) which is often abbreviated to “ISO 15765‑4 (CAN 11/500).”
Each CAN bus carries messages relating to a different aspect of the vehicle’s operation:
- AV‑CAN
Messages related to the display screen.
- Car‑CAN
Messages related to general vehicle operation including EV related messages.
- EV‑CAN
Messages related to the battery and drive system.
Contact designation
Figure 2 depicts the mating-end view of the OBD-II vehicle diagnostic connector. Colours of the CAN bus symbols are selected to correspond with the colour code of four-pair ethernet cable.
Figure 2 Nissan Leaf OBD-II diagnostic connector contact designation (mating-end view)
As depicted in Table 1, the Leaf uses five contacts with a mandated designation: chassis ground, signal ground, Car‑CAN high, Car‑CAN low, and permanent +12 V DC. Designation of the remaining pins is specific to the Leaf: AV‑CAN low, +12 V DC when vehicle powered on, AV‑CAN high, EV‑CAN low, and EV‑CAN high.
Pin |
Symbol1 |
Designation |
|---|---|---|
1 |
|
No connection |
2 |
|
No connection2 |
3 |
|
AV‑CAN low3 |
4 |
|
Chassis ground2 |
5 |
|
Signal ground2 |
6 |
|
Car‑CAN high2 |
7 |
|
No connection2 |
8 |
|
+12 V DC when vehicle powered on3 |
9 |
|
No connection |
10 |
|
No connection2 |
11 |
|
AV‑CAN high3 |
12 |
|
EV‑CAN low3 |
13 |
|
EV‑CAN high3 |
14 |
|
Car‑CAN low2 |
15 |
|
No connection2 |
16 |
|
Permanent +12 V DC2 |
