ENGINE (DIAGNOSTICS)(H4DO) > Diagnostics for Engine Starting Failure

IGNITION CONTROL SYSTEM

CAUTION:

After servicing or replacing faulty parts, perform Clear Memory Mode and Inspection Mode .

WIRING DIAGRAM:

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1.CHECK SPARK PLUG CONDITION.

1) Remove the spark plug.

2) Check the spark plug condition.

Is the spark plug condition OK?

Replace the spark plug.

2.CHECK IGNITION SYSTEM FOR SPARKS.

1) Connect the spark plug to ignition coil.

2) Release the fuel pressure.

3) Contact the spark plug thread portion to engine.

4) While opening the throttle valve fully, crank the engine to check that spark occurs at each cylinder.

Does spark occur at each cylinder?

Check fuel pump system.

3.CHECK POWER SUPPLY CIRCUIT OF IGNITION COIL.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from ignition coil.

3) Turn the ignition switch to ON.

4) Measure the power supply voltage between ignition coil connector and engine ground.

Connector & terminal

(E31) No. 3 (+) — Engine ground (−):

(E32) No. 3 (+) — Engine ground (−):

(E33) No. 3 (+) — Engine ground (−):

(E34) No. 3 (+) — Engine ground (−):

Is the voltage 10 V or more?

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit of harness between ignition coil and ignition switch connector

• Poor contact of coupling connector

4.CHECK HARNESS OF IGNITION COIL GROUND CIRCUIT.

1) Turn the ignition switch to OFF.

2) Measure the resistance between ignition coil connector and engine ground.

Connector & terminal

(E31) No. 2 — Engine ground:

(E32) No. 2 — Engine ground:

(E33) No. 2 — Engine ground:

(E34) No. 2 — Engine ground:

Is the resistance less than 5 Ω?

Repair the open circuit in harness between ignition coil connector and engine ground.

5.CHECK HARNESS BETWEEN ECM AND IGNITION COIL CONNECTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connectors from ECM.

3) Disconnect the connector from ignition coil.

4) Measure the resistance of harness between ECM and ignition coil connector.

Connector & terminal

(B134) No. 22 — (E34) No. 1:

(B134) No. 23 — (E33) No. 1:

(B134) No. 24 — (E32) No. 1:

(B134) No. 25 — (E31) 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 ignition coil connector

• Poor contact in coupling connector

6.CHECK HARNESS BETWEEN ECM AND IGNITION COIL CONNECTOR.

Measure the resistance of harness between ECM and engine ground.

Connector & terminal

(B134) No. 22 — Engine ground:

(B134) No. 23 — Engine ground:

(B134) No. 24 — Engine ground:

(B134) No. 25 — Engine ground:

Is the resistance 1 MΩ or more?

Repair the ground short circuit of harness between ECM and ignition coil connector.

7.CHECK POOR CONTACT.

Check for poor contact of ECM connector.

Is there poor contact in ECM connector?

Repair poor contact in ECM connector.

Check fuel pump circuit.