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 OPERATION OF CHECK ENGINE MALFUNCTION INDICATOR LAMP (MIL).
1) Turn ignition switch to OFF.

2) Disconnect test mode connector.





3) Turn ignition switch to ON.

CHECK: Does the MIL come on?

YES: Go to step 7C2.

NO: Repair the MIL circuit.

7C2: CHECK OUTPUT SIGNAL FROM ECM.





Measure voltage between test mode connector and chassis ground.

CHECK: Is voltage less than 1 V?

YES: Go to step 7C3.

NO: Go to step 7C5.

7C3: CHECK HARNESS BETWEEN ECM AND TEST MODE CONNECTOR.
1) Turn ignition switch to OFF.

2) Disconnect connector from ECM.





3) Measure resistance of harness between ECM and test mode connector.

CHECK: Is resistance less than 1 Ohm?

YES: Go to step 7C4.

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

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: Replace ECM.

7C5: CHECK GROUND CIRCUIT.
1) Turn ignition switch to OFF.

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

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

CHECK: Is resistance less than 5 Ohms?

YES: Repair poor contact in test mode connector.

NO: Repair harness and connector.

NOTE:
In this case, repair the following:
- Open circuit in harness between test mode and coupling connector (B22)
- Open circuit in harness between coupling connector (B22) and engine grounding terminal
- Poor contact in coupling connector (B22)