Check MIL Does Not Blink At A Cycle of 3 Hz

C: CHECK ENGINE MALFUNCTION INDICATOR LAMP (MIL) DOES NOT BLINK AT A CYCLE OF 3 Hz.

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

TROUBLE SYMPTOM:
- When inspection mode, MIL does not blink at a cycle of 3 Hz.

Wiring Diagram:

WIRING DIAGRAM

7C1: CHECK STATUS OF CHECK ENGINE MALFUNCTION INDICATOR LAMP (MIL).

1. Turn ignition switch to OFF.
2. Disconnect test mode connector.





3. Turn ignition switch to ON. (engine OFF)

CHECK: Does the MIL come on?

YES: Go to step 7C2.

NO: Repair the MIL circuit.

7C2: CHECK HARNESS BETWEEN COMBINATION METER AND ECM CONNECTOR.

1. Turn ignition switch to OFF.
2. Disconnect connector from ECM.





3. Turn ignition switch to ON.

CHECK: Does the MIL come on?

YES: Repair ground short circuit in harness between combination meter and ECM connector.

NO: Go to step 7C3.

7C3: CHECK HARNESS BETWEEN TEST MODE CONNECTOR AND CHASSIS GROUND.

1. Turn ignition switch to OFF.
2. Disconnect connector from ECM.

Connector & Terminal - [(B76) No.1 - Chassis Ground]:

3. Measure resistance of harness between test mode connector and chassis ground.

CHECK: Is resistance less than 1 Ohm?

YES: Go to step 7C4.

NO: Repair harness and connector.

NOTE: In this case, repair the following:
- Open circuit in harness between test mode connector and chassis ground

7C4: CHECK POOR CONTACT.
Check poor contact in ECM connector.

CHECK: Is there poor contact in ECM connector?

YES: Repair poor contact in ECM connector.

NO: Go to step 7C5.

7C5: CHECK HARNESS BETWEEN ECM AND TEST MODE CONNECTOR.

1. Connect test mode connector.

Connector & Terminal - [(B135) No.14 - Chassis Ground]:

2. Measure resistance of harness between ECM and chassis ground.

CHECK: Is resistance less than 1 Ohm?

YES: Go to step 7C6.

NO: Repair open circuit in harness between ECM and test mode connector.

7C6: CHECK POOR CONTACT.
Check poor contact in ECM connector.

CHECK: Is there poor contact in ECM connector?

YES: Repair poor contact in ECM connector.

NO: Replace ECM.