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

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.




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

CHECK: Is resistance less than 1 Ohms?

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.




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

CHECK: Is resistance less than 1 Ohms?

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.