Bendix Commercial Vehicle Systems VORAD VS-400 INSTALLATION NOTES - Manual (Page 23)

General Information
21
Pretest Procedures
Step Procedure
M 1. Vehicle Ignition: Key-OFF.
2 . Measure the resistance across pins 4 and 9 (J1939 High to Ground) .
3 . Measure the resistance across pins 5 and 9 (J1939 Low to Ground) .
a. If the resistance is greater than 100K ohms or open (Infinite Resistance).
i .
Test Complete .
b. If the resistance is between 0 to 100K ohms.
i . Test Failed . Check for shorted connections in the vehicle's J1939 data link harness .
Unplug all J1939 data link components from the data link to isolate a potential
defective component . (See Note)
Note: Refer to vehicle OEM repair manual or contact the OEM for more information on the J1939 data link harness .