How to use a Jumper Box to connect to J1939 3pin (Cummins) OBD Connector
3 Pin Deutsch J1939 Backbone Connector as shown below
Pin |
Value |
A |
CAN/J1939 Hi |
B |
CAN/J1939 Lo |
C |
CAN/J1939 Shield |
FCAR Jumper Box to 3 Pin mapping:
-
Pin 1 Pin 6 pin out to A (CAN/J1939 Hi, 2.6v) Pin 10 - Power LED Pin 2 Pin 7 Pin 11 Pin 14 pin out to B (CAN/J1939 Lo- 2.4v) Pin 3 Pin 8 J1939 Sheild Pin 12 Pin 15 Pin 4 (GND-) pin out to battery nagative Pin 9 Pin 13 Pin 16 (VCC+) pin out to Battery 12v positive
in short, connect pin A to 6 and pin B to 14, pin C is CAN Shield, you can pin out to Pin 8.
When you plug in the main diagnostic scan tool lead (FCAR DB15) you can try to use the program Diesel OBD at first scan to see whether it will communicate and then try to use program to scan. From ECU information page, you will see if this is a Cummins engine.
If this is the Cummins engine, please select Diesel Engine and Cummins program to have all bi-directional features.