Diagnostic Test Procedures

Each diagnostic trouble code is diagnosed by following a specific testing procedure. The diagnostic test procedures contain step-by-step instructions for determining cause of trouble codes as well as no trouble code problems. It is not necessary to perform all of tests in this book to diagnose an individual code.

Always begin by reading diagnostic trouble codes using DRBIII(R). This will direct you to specific test(s) that must be performed. DTC tests are organized by scan tool "P" code number. See DTC CODES & MESSAGES  table.