J1939 Pinout Diagram for 9-Pin CAN Connector Wiring
9-pin circular connector
Standards: SAE J1939-13, SAE J1939-11, SAE J1708, SAE J1587
What is the J1939 (Deutsch) pinout?
The J1939 Deutsch 9-Pin Connector has 9 pins. Pin A is GND (ground). Pin B is BAT (power). Pin C is CAN-H (data). Pin D is CAN-L (data). Plus 5 more pins.
Standards: SAE J1939-13, SAE J1939-11, SAE J1708, SAE J1587
Pin Assignment Table
| Pin | Signal | Type | Description |
|---|---|---|---|
| A | GND | ground | Battery Ground |
| B | BAT | power | Battery Positive (Unswitched 12V/24V) |
| C | CAN-H | data | J1939 CAN High (Yellow) |
| D | CAN-L | data | J1939 CAN Low (Green) |
| E | Shield | shield | CAN Shield (Drain) |
| F | J1708+ | data | J1708/J1587 Data+ (Legacy) |
| G | J1708- | data | J1708/J1587 Data- (Legacy) |
| H | OEM | reserved | OEM Specific |
| J | OEM | reserved | OEM Specific |
Signal Types
Common Applications
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Map this connector into the release workflow →The J1939 (Deutsch) connector has 9 pins: Pin A (GND), Pin B (BAT), Pin C (CAN-H), and Pin D (CAN-L). Plus 5 more pins. Common in Heavy Trucks and Agriculture.
SAE J1939 9-Pin Diagnostic Connector
The J1939 connector (Deutsch HD10 series) is the standard diagnostic port for heavy-duty vehicles including Class 4-8 trucks, agricultural tractors, construction equipment, and marine applications. The Type 2 Green connector supports 500 kbps CAN bus for modern J1939 networks, while the older Type 1 Black connector supports 250 kbps. Most vehicles manufactured after 2001 use the green connector exclusively.
Wiring Tips & Best Practices
Pin A (center) is Battery Ground and must be connected for any communication. Pins C (CAN-H, Yellow) and D (CAN-L, Green) are the J1939 CAN bus pair - always use twisted pair cable with 120 ohm characteristic impedance. Pins F and G carry legacy J1708/J1587 serial data for older vehicles. Pin B provides unswitched battery power (typically 12V or 24V). For DIY adapters, ensure 120-ohm termination resistors are placed at each end of the CAN bus segment.
Common Issues
CAN bus communication failures often result from missing termination resistors or incorrect cable impedance. The Type 1 (Black) vs Type 2 (Green) connectors operate at different baud rates - using the wrong adapter will fail to communicate. Pin E (Shield) should be connected to chassis ground at one end only to prevent ground loops. When tapping into the diagnostic port for telematics, avoid overloading the CAN bus with too many devices - the J1939 spec recommends a maximum of 30 ECUs per segment.
Why Use Interactive Diagrams?
- Accuracy: Hover over pins to see exact signal names and descriptions
- Clarity: Color-coded by signal type (power, ground, data)
- Printable: Export clean diagrams for shop floor reference