Connecting a J1939 diagnostic tool to a vehicle with an OBD2 style connector often requires a specialized adapter. This article discusses the OBD2 to 9 pin adapter, its wiring, and various applications, focusing on Hino trucks. Understanding these adapters is crucial for technicians working with heavy-duty vehicles.
Understanding the OBD2 to 9 Pin Adapter for Hino Trucks
Hino trucks, like many heavy-duty vehicles, utilize the J1939 communication protocol for diagnostics. However, some Hino models feature an OBD2 style diagnostic port, requiring an adapter to connect a standard 9-pin J1939 diagnostic tool. There are two versions of this adapter available, one for older and one for newer Hino models (approximately 2014 and newer).
Wiring Specifications: Decoding the Connections
The wiring configuration for each adapter version is crucial for proper functionality. The table below outlines the pin connections for both old and new style Hino adapters:
| 16-pin (OBD2) | Old Signal | Old J1939 | New Signal | New J1939 |
|---|---|---|---|---|
| 1 | 24V Battery | B | 24V Battery | B |
| 2 | ISO-L Line | – | J1939+ | C |
| 3 | J1939- | D | J1939- | D |
| 6 | Autolevel Rx | – | – | – |
| 7 | – | – | ISO-K Line | – |
| 9 | Autolevel Init | – | – | – |
| 10 | ISO-K Line | – | – | – |
| 11 | J1939+ | C | – | – |
| 12 | Signal Ground | A | – | – |
| 13 | Chassis Ground | – | – | – |
| 14 | Autolevel Tx | – | – | – |
| 15 | – | – | Ground | – |
| 15 | – | – | Ground | A |
This detailed pinout ensures accurate data transmission between the diagnostic tool and the vehicle’s J1939 network. Identifying the correct adapter for your Hino truck’s model year is essential.
Other J1939 and OBD2 Adapter Applications
Beyond Hino trucks, various other adapters facilitate communication between J1939 and OBD2 systems. These include:
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J1939 Female to OBD2 Female: Enables connection of an OBD2 diagnostic tool to a vehicle with a J1939 9-pin connector. Commonly used for connecting GPS trackers designed for OBD2 vehicles to heavy-duty trucks.
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J1939 Male to OBD2 Male: Allows a J1939 scan tool to connect to a vehicle equipped with an OBD2 style connector.
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Volvo M-M Adapter: Specifically designed for Volvo trucks manufactured from 2013 onwards, accommodating their unique OBD2 style diagnostic connector.
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GMC Top Kick M-M Adapter: Enables connection of a J1939/J1708 tester to GMC Top Kick trucks with Cummins or CAT engines.
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Allison to J1939 Adapter: Addresses the grounding difference in Allison and some Detroit Diesel vehicles, allowing connection of standard J1939 accessories.
Finding the right adapter is crucial for accurate diagnostics and troubleshooting. Consult your vehicle’s documentation or a qualified technician to ensure compatibility. Having the correct OBD2 to 9 pin adapter ensures seamless communication with your vehicle’s diagnostic system.
