Navigating the world of heavy-duty vehicle diagnostics often involves understanding different connector types and communication protocols. Two common standards you’ll encounter are J1939 and OBD2. While OBD2 is widely recognized in passenger vehicles, J1939 is the standard for many commercial vehicles, trucks, and buses. When you need to bridge these two systems, understanding the J1939 To Obd2 Pinout becomes essential.
This article will break down the pin configuration for adapting a J1939 connection to an OBD2 interface, specifically focusing on the Volvo OBD2 style connector and general J1939 adapter wiring. We’ll also explore various adapter types available in the market to help you find the right solution for your diagnostic or connectivity needs.
Volvo J1939 (OBD2 Style Male) Connector Pinout
Volvo, among other manufacturers, has adopted an OBD2 style connector for J1939 diagnostics in some of their chassis and engines. This connector, while physically resembling an OBD2 port, carries J1939 and other communication protocols. Here’s the pinout for the Volvo OBD2 style diagnostic connector:
| Pin Number | Signal |
|---|---|
| 3 | J1939+ |
| 5 | GND |
| 6 | ISO15765+ |
| 11 | J1939- |
| 12 | J1708+ |
| 13 | J1708- |
| 14 | ISO15765- |
| 16 | BATTERY |
Understanding this pinout is crucial when you need to connect a standard J1939 diagnostic tool or device to a Volvo vehicle equipped with this OBD2 style connector. Incorrect wiring can lead to communication issues or even damage to your equipment or the vehicle’s electronic systems.
Wiring Connections for a J1939 to OBD2 Adapter
To create a functional adapter, you need to correctly wire the Volvo OBD2 style connector to a standard J1939 connector, typically a 9-pin Deutsch connector. Here’s a common wiring configuration for such an adapter:
| Volvo (OBD2 Style) | Signal | J1939 (9-Pin Deutsch) |
|---|---|---|
| 5 | Ground | A |
| 16 | Battery | B |
| 3 | J1939+ (High) | C |
| 11 | J1939- (Low) | D |
| 12 | J1708+ | F |
| 13 | J1708- | G |
This table outlines the essential connections for basic J1939 communication and power. Depending on your application, you might only need the J1939 +/- and power/ground connections. For instance, if you’re using a J1939 scanner, these are the primary pins required. If you’re working with J1708 systems, the J1708 +/- connections become relevant.
Exploring Different J1939 to OBD2 Adapter Types
Beyond the Volvo specific adapter, various other J1939 to OBD2 adapters cater to different needs and vehicle types. Here are some common examples:
J1939 Female to OBD2 Female Adapter
This type of adapter is commonly used to connect OBD2 based devices, like GPS trackers or telematics units, to vehicles equipped with a J1939 port, often the 9-pin Deutsch connector. It essentially translates the J1939 signals to be compatible with an OBD2 female connector.
J1939 Male to OBD2 Male Adapter
Conversely, this adapter allows you to use a J1939 scan tool, designed for the round 9-pin Deutsch J1939 connector, with a vehicle that uses an OBD2 style J1939 diagnostic port. This is particularly useful for technicians who have J1939 diagnostic equipment and need to work on vehicles with the OBD2 style connector.
Volvo Male to Male Adapter
Specifically designed for Volvo vehicles with the new OBD2 style diagnostic connector introduced around 2013, this adapter enables connection with standard J1939 testers using the 9-pin Deutsch connector. It’s tailored to bridge the gap between Volvo’s new connector style and existing J1939 diagnostic tools.
GMC Top Kick Male to Male Adapter
For GMC Top Kick trucks, the diagnostic connector can be OBD2 style, but the data protocol varies. Models with Cummins engines use J1708, while CAT engine models use J1939. This adapter is designed to connect a J1939/J1708 tester with a standard 9-pin J1939 connector to the GMC Top Kick’s OBD2 style port, ensuring compatibility with both data protocols.
Hino Truck Male to Male Adapter
Similar to GMC Top Kick, Hino trucks may also feature an OBD2 style connector while utilizing J1939 communication. This adapter facilitates the connection of a standard J1939 tester with a 9-pin Deutsch connector to Hino trucks equipped with the OBD2 style diagnostic port.
Allison to J1939 Adapter
Allison transmissions and some Detroit Diesel vehicles with 16-pin OBD2 style diagnostic connectors have a different ground pin configuration (pin 4 instead of pin 5). This adapter corrects this discrepancy, allowing standard J1939 accessories or testers with 9-pin plugs to connect correctly to Allison diagnostic ports.
Conclusion
Understanding the J1939 to OBD2 pinout is fundamental for anyone working with heavy-duty vehicle diagnostics and telematics. Whether you are connecting diagnostic tools, GPS trackers, or other accessories, ensuring correct pin assignments and adapter compatibility is crucial for seamless communication and preventing potential damage.
If you can’t find a pre-made adapter for your specific needs, remember that custom cable solutions are often available. Consider exploring custom cable services to get a tailored adapter that perfectly matches your unique requirements.
