Use Diagnostic Trouble Codes (DTCs) (from the DTC checks) in the table below to determine the trouble area and proper inspection procedure. The Supplemental Restraint System (SRS) diagnostic trouble code chart is shown below as an example.

Symptom simulation
Problem symptoms tableSelecting trailer ball
Use the correct trailer ball for your application.
Trailer ball load rating
matches or exceeds the gross
trailer weight rating of the trailer.
Ball diameter
matches the size of the trailer coupler.
Most couplers are stamped
with the required trailer ball size.
Shank len ...