Self-Diagnostic System: Notes
Self-diagnostic system will operate in 2 modes which are manually selected using a screwdriver through access port on ECM. With ignition switch in ON position and engine not running, use screwdriver to turn switch fully clockwise. Wait at least 2 seconds. Turn screwdriver fully counterclockwise. MIL will begin to flash.
NOTE:
Modes cannot be switched while engine is running. When ignition switch is turned to OFF position while in Mode II, ECM switches to Mode I.