Description of On-Board Diagnostics

This section uses diagnostic tables, wiring diagrams and descriptive text in order to direct you in performing specific tests in order to locate and repair the problem. The diagnostic table is a step by step procedure in order to determine the circuit or component that is the source of the problem. The wiring diagrams and the text describing the system, test conditions, failure conditions and actions taken when a DTC is set are located on the page facing the diagnostic table.

Diagnostic trouble codes (DTC)s, when set, indicate that the IPC has detected a malfunction in a particular circuit or other system. Other system malfunctions are generally, but not exclusively, reported to the IPC via the Class 2 data message. The IPC is programmed with routines for internal checks that the IPC follows only under prescribed conditions (called Test Conditions). When these conditions exist, the IPC tests certain circuits or systems for a malfunction. These tests are called failure conditions or conditions for setting the DTC. When these conditions are true, a DTC is set. The IPC may turn a telltale Malfunction Indicator Lamp (MIL) ON. Refer to the applicable DTC Table for procedures and details. B Code Charts