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. Note that many electronic engine control tests require the use of a "Scan" tool.
For Diagnostic Circuit Check Charts, refer to DIAGNOSTIC CHARTS.