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.

Nissan Leaf OBD-II diagnostic connector — 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.

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.

Table 1 *Nissan Leaf* vehicle diagnostic connector contact designation
Pin	Symbol[1]	Designation
1		No connection
2		No connection[2]
3		AV‑CAN low[3]
4		Chassis ground[2]
5		Signal ground[2]
6		Car‑CAN high[2]
7		No connection[2]
8		+12 V DC when vehicle powered on[3]
9		No connection
10		No connection[2]
11		AV‑CAN high[3]
12		EV‑CAN low[3]
13		EV‑CAN high[3]
14		Car‑CAN low[2]
15		No connection[2]
16		Permanent +12 V DC[2]