Malfunction Indicator Lamp Flashes with Ignition Switch ON
Wiring Diagram
1. Relay box 5. Malfunction indicator lamp in combination meter 9. “IGN1” fuse
2. Ignition switch 6. “FI” fuse 10. ECM
3. Fuse box 7. “IG” fuse 11. Monitor connector
4. Main relay 8. “MTR” fuse      
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 Action YES NO
MIL flashing pattern check
1) With the ignition switch ON position, check MIL flashing pattern.
Does MIL flashing pattern indicate DTC (diagnostic trouble code)?
Go to Step 2.
Diagnosis switch terminal check
1) With the ignition switch ON position, check voltage between “E114-13” terminal of ECM coupler and ground.
Is voltage 4 – 5 V?
Substitute a known-good ECM and recheck.
“WHT/BLU” wire (diagnosis switch terminal) shorted to ground circuit. If OK, substitute a known-good ECM and recheck.