MIL Does Not Come ON or Dims Ignition Switch On, Engine Off

Malfunction Indicator Lamp Does Not Come "ON" or DIMS at Ignition Switch ON (But Engine at Stop)

Wiring Diagram:

Wiring Diagram

Circuit Description
When the ignition switch is turned ON, ECM causes the main relay to turn ON (close the contact point). Then, ECM being supplied with the main power, turns ON the malfunction indicator lamp (MIL). When the engine starts to run and no malfunction is detected in the system, MIL goes OFF but if a malfunction was or is detected, MIL remains ON even when the engine is running.

Step 1 - 2:

Troubleshooting