Check MIL Does Not Come ON

A:CHECK ENGINE MALFUNCTION INDICATOR LAMP (MIL) DOES NOT COME ON.

DIAGNOSIS:
- The CHECK ENGINE malfunction indicator lamp (MIL) circuit is open or shorted.

TROUBLE SYMPTOM:
- When ignition switch is turned ON (engine OFF), MIL does not come on.




WIRING DIAGRAM

7A1: CHECK OUTPUT SIGNAL FROM ECM.

1. Turn ignition switch to ON.




2. Measure voltage between ECM connector and chassis ground.

CHECK: Is the voltage less than 1 V?

YES: Go to step 7A4.

NO: Go to step 7A2.

7A2: CHECK POOR CONTACT.

CHECK: Does the MIL come on when shaking or pulling ECM connector and harness?

YES: Repair poor contact in ECM connector.

NO: Go to step 7A3.

7A3: CHECK ECM CONNECTOR.

CHECK: Is ECM connector correctly connected?

YES: Replace ECM.

NO: Repair connection of ECM connector.

7A4: CHECK HARNESS BETWEEN COMBINATION METER AND ECM CONNECTOR.
1. Turn ignition switch to OFF.
2. Remove combination meter.
3. Disconnect connector from ECM and combination meter.




4. Measure resistance of harness between ECM and combination meter connector.

CHECK: Is resistance less than 1 Ohms?

YES: Go to step 7A5.

NO: Repair harness and connector.

NOTE: In this case, repair the following:
- Open circuit in harness between ECM and combination meter connector
- Poor contact in coupling connector (i2)

7A5: CHECK POOR CONTACT.
Check poor contact in combination meter connector.

CHECK: Is there poor contact in combination meter connector?

YES: Repair poor contact in combination meter connector.

NO: Go to step 7A6.

7A6: CHECK HARNESS BETWEEN COMBINATION METER AND IGNITION SWITCH CONNECTOR.
1. Turn ignition switch to ON.




2. Measure voltage between combination meter connector and chassis ground.

CHECK: IS voltage more than 10 V?

YES: Go to step 7A7.

NO: Check the following and repair if necessary.

NOTE:
- Broken down ignition relay.
- Blown out fuse (No.5).
- If replaced fuse (No.5) blows easily, check the harness for short circuit of harness between fuse (No.5) and ignition relay connector.
- Open or short circuit in harness between fuse (No.5) and battery terminal
- Open circuit in harness between fuse (No.5) and ignition relay connector
- Poor contact in ignition relay connector
- Poor contact in ignition switch connector

7A7: CHECK LAMP BULB.
Remove engine malfunction indicator lamp bulb.

CHECK: Is lamp bulb condition OK?

YES: Repair combination meter connector.

NO: Replace lamp bulb.