ENGINE (DIAGNOSTICS)(H4DO) > Malfunction Indicator Light > MALFUNCTION INDICATOR LIGHT DOES NOT BLINK

ENGINE (DIAGNOSTICS)(H4DO) > Malfunction Indicator Light

MALFUNCTION INDICATOR LIGHT DOES NOT BLINK

DIAGNOSIS:

• The malfunction indicator light circuit is open or shorted.

• The delivery (test) mode connector circuit is open.

TROUBLE SYMPTOM:

Malfunction indicator light does not blink during Inspection Mode.

WIRING DIAGRAM:

STEP	CHECK	YES	NO
1.CHECK STATUS OF MALFUNCTION INDICATOR LIGHT. 1) Turn the ignition switch to OFF. 2) Disconnect the delivery (test) mode connector. 3) Turn the ignition switch to ON. (engine OFF)	Does the malfunction indicator light illuminate?		Repair the malfunction indicator light circuit.
2.CHECK HARNESS BETWEEN ECM AND COMBINATION METER CONNECTOR. 1) Turn the ignition switch to OFF. 2) Disconnect the connector from ECM. 3) Turn the ignition switch to ON.	Does the malfunction indicator light illuminate?	Repair the ground short circuit of harness between ECM and combination meter connector.
3.CHECK HARNESS BETWEEN ECM AND DELIVERY (TEST) MODE CONNECTOR. 1) Turn the ignition switch to OFF. 2) Disconnect the connector from ECM. 3) Measure the resistance of harness between delivery (test) mode connector and chassis ground. Connector & terminal (B76) No. 1 — Chassis ground:	Is the resistance less than 1 Ω?		Repair the harness and connector. NOTE: In this case, repair the following item: • Open circuit in harness between delivery (test) mode connector and chassis ground • Poor contact of joint connector • Poor contact of coupling connector
4.CHECK HARNESS BETWEEN ECM AND DELIVERY (TEST) MODE CONNECTOR. Measure the resistance of harness between ECM and delivery (test) mode connector. Connector & terminal (B135) No. 22 — (B75) No. 1:	Is the resistance less than 1 Ω?		Repair the harness and connector. NOTE: In this case, repair the following item: • Open circuit of harness between ECM and delivery (test) mode connector • Poor contact of test mode sub connector
5.CHECK POOR CONTACT. Check for poor contact of ECM connector.	Is there poor contact of ECM connector?	Repair the poor contact of ECM connector.	Replace the ECM.