Diagnostic Circuit Check

Diagnostic Circuit Check:

NOTE: Check and correct any problems with vacuum hoses, electrical harness connections and routing before proceeding with this check.

The Diagnostic Circuit Check ensures that the on-board diagnostic system is functioning, determines the trouble codes to be displayed and guides diagnosis to other problem areas.

Be aware that open circuits are often difficult to locate by sight because terminal misalignment or oxidation are hidden by connectors. An open circuit condition can often be discovered by wiggling a connector on a sensor or in the wiring harness. This should always be considered when troubleshooting has indicated an open circuit or failed sensor in the system.

For Diagnostic Circuit Check Charts, refer to DIAGNOSTIC CHARTS.