Circuit Test D8 - "Check Engine" Malfunction Indicator Light
NOTE:
Enter this test only when directed here from DIAGNOSTIC ROUTINES or other test procedure. To prevent replacement of good components, be aware that the following non-EEC areas may be at fault: fuse, bulb or socket. This test is intended to diagnose only the following: ECA and harness circuit (MIL).
- Checking System Integrity - Visually check all wiring, harnesses, connectors and components for evidence of damage, overheating, shorting or looseness. If a fault is found, repair as necessary. If no faults are found, go to next step.
- Checking ECA Ground - Install breakout box, leaving ECA disconnected. With KOEO, jumper test pin No. 51 to test pin No. 20 (ground). If "CHECK ENGINE" light is on, go to CIRCUIT TEST B12 , step 1). If light is off, go to next step.
- Checking MIL Circuit For Power - Ensure MIL is connected. DO NOT pierce wire during test procedure. With KOEO, ground "W/BL" wire with jumper at connector "C235" (located at rear of instrument panel). If "CHECK ENGINE" light is on, repair "W/BL" wire between MIL light and ECA. If not, repair power circuit to "CHECK ENGINE" light or replace bulb as necessary.