Understanding the Obd2 J1939 Pinout is crucial when working with Volvo and other heavy-duty vehicles utilizing the SAE J1939 standard but with an OBD2 style connector. This guide will clarify the pin assignments and explain how to interface with these systems effectively.
Volvo, starting from 2013, adopted a new diagnostic connector style that resembles the OBD2 connector commonly found in passenger vehicles. However, under the hood, these connectors operate on the J1939 protocol, which is standard for heavy-duty trucks and buses. This shift can be confusing, as standard OBD2 tools won’t directly communicate with these J1939 systems. This is where understanding the OBD2 J1939 pinout and the necessary adapters becomes essential.
Volvo OBD2 (Male) J1939 Pinout Diagram
The following table details the pinout for the Volvo OBD2 style diagnostic connector, specifically outlining the J1939 signal assignments:
| Pin Number | Signal |
|---|---|
| 3 | J1939+ |
| 5 | GND |
| 6 | ISO15765+ |
| 11 | J1939- |
| 12 | J1708+ |
| 13 | J1708- |
| 14 | ISO15765- |
| 16 | BATTERY |
This pinout reveals that while the connector physically resembles OBD2, it carries both J1939 and J1708 communication protocols, alongside power and ground. Pins 3 and 11 are specifically designated for the J1939 CAN bus high (+) and low (-) signals, respectively.
Alt text: Wiring diagram for Volvo OBD2 to J1939 adapter, illustrating pin connections between Volvo OBD2 style connector and standard J1939 connector.
Wiring Connections for J1939 Adapters
To connect standard J1939 diagnostic tools or devices to these Volvo OBD2 style connectors, adapters are necessary. These adapters bridge the gap between the OBD2 physical interface and the standard J1939 9-pin Deutsch connector. Here’s a typical wiring configuration for such adapters:
| Volvo Pin | Signal | J1939 Pin |
|---|---|---|
| 5 | Ground | A |
| 16 | Battery | B |
| 3 | J1939+ (H) | C |
| 11 | J1939- (L) | D |
| 12 | J1708+ | F |
| 13 | J1708- | G |
This table clarifies how each pin on the Volvo OBD2 connector corresponds to the pins on a standard J1939 connector. Notably, pins A, B, C, and D of the J1939 connector are crucial for J1939 communication and power, while F and G are for older J1708/J1587 networks, which might also be present in some Volvo systems.
Adapter Solutions for Volvo J1939 OBD2 and Beyond
Beyond Volvo, several other heavy-duty applications utilize OBD2 style connectors with J1939 or related protocols. Adapters are available for various scenarios:
- J1939 Female to OBD2 Female: For connecting OBD2 GPS trackers or scanners to J1939 vehicles with a standard Deutsch connector.
Alt text: Image of a J1939 female to OBD2 female adapter, designed to connect OBD2 devices to vehicles with J1939 9-pin ports.
- J1939 Male to OBD2 Male: Enables J1939 scan tools (designed for the 9-pin Deutsch) to be used with vehicles that have an OBD2 style J1939 connector.
Alt text: Photograph of a J1939 male to OBD2 male adapter, used for connecting J1939 scanners to OBD2 style J1939 ports.
- Volvo M-M Adapter: Specifically for Volvo chassis with Volvo engines from 2013 onwards, allowing standard J1939 testers to connect to the new OBD2 style diagnostic port.
Alt text: Picture of a Volvo male to male J1939 adapter, designed for connecting standard J1939 tools to Volvo’s OBD2 style diagnostic connectors.
- GMC Top Kick M-M Adapter: For GMC Top Kick trucks, accommodating both Cummins (J1708) and CAT (J1939) engines with OBD2 style connectors, allowing connection of J1939/J1708 testers.
Alt text: Image of a GMC Top Kick male to male J1939 adapter, facilitating connection to Top Kick trucks with OBD2 style ports using J1939/J1708 testers.
- Hino Truck M-M Adapter: For Hino trucks with OBD2 style connectors, enabling the use of standard J1939 testers.
Alt text: Hino truck male to male J1939 adapter, designed for connecting J1939 testers to Hino trucks equipped with OBD2 style diagnostic ports.
- Allison to J1939 Adapter: Addresses specific wiring differences in Allison transmissions and some Detroit Diesel applications where ground is on pin 4 instead of pin 5 in the OBD2 style connector.
Alt text: Allison to J1939 adapter, addressing specific grounding configurations in Allison and Detroit Diesel OBD2 style connectors for J1939 device compatibility.
Conclusion
Navigating the world of heavy-duty diagnostics requires understanding the nuances of connectors and protocols. The Volvo OBD2 J1939 pinout is a prime example of where physical appearance might be misleading. By understanding the pin assignments and utilizing the correct adapters, technicians and vehicle operators can effectively diagnose and interface with these advanced vehicle systems. If you require a specific configuration not listed, custom cable solutions are also available to meet your unique diagnostic needs.
