15
Pretest Procedures
Step Procedure
G 1. VehicleIgnition:Key-OFF.
2. Measure the resistance across pins 7 and 5 (J1939 High to Ground.)
3. Measure the resistance across pins 6 and 5 (J1939 Low to Ground.)
a. Ifbothresistancesaregreaterthan100Kohmsoropen(InniteResistance).
i. Proceed to Step H.
b. Ifeitherresistanceisbetween0to100Kohms.
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.
V
COM
A
Pin #Description