ENGINE (DIAGNOSTICS)(H4DOTC DIESEL) > Diagnostics for Engine Starting Failure

STARTER MOTOR CIRCUIT

1. MODEL WITHOUT PUSH BUTTON START

CAUTION:

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

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK BATTERY.

Check the battery voltage.

Is the voltage 12 V or more?

Charge or replace the battery.

2.CHECK OPERATION OF STARTER MOTOR.

Does the starter motor operate?

3.CHECK DTC.

Is DTC displayed?

Check the appropriate DTC using the List of Diagnostic Trouble Code (DTC).

The circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

NOTE:

In this case, temporary poor contact of connector may be the cause.

4.CHECK INPUT SIGNAL FOR STARTER MOTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from starter motor.

3) Turn the ignition switch to START.

4) Measure the voltage between the starter motor connector terminal and the engine ground.

Connector & terminal

(B14) No. 1 (+) — Engine ground (−):

Is the voltage 10 V or more?

Check the starter motor.

5.CHECK HARNESS BETWEEN BATTERY AND IGNITION SWITCH CONNECTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from ignition switch.

3) Measure the voltage between ignition switch connector and chassis ground.

Connector & terminal

(B72) No. 3 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Check the following item and repair or replace if necessary.

• Blown out of fuse

• Open or short circuit to ground in harness between ignition switch connector and battery

6.CHECK IGNITION SWITCH.

Measure the resistance between ignition switch terminals after turning the ignition switch to START position.

Terminals

No. 3 — No. 2:

No. 3 — No. 6:

Is the resistance less than 5 Ω?

Replace the ignition switch.

7.CHECK INPUT VOLTAGE OF STARTER RELAY.

1) Turn the ignition switch to OFF.

2) Remove the starter relay.

3) Connect the connector to ignition switch.

4) Measure the voltage between starter relay connector and chassis ground after turning the ignition switch to START position.

Connector & terminal

LHD model

(B225) No. 9 (+) — Chassis ground (−):
(B225) No. 11 (+) — Chassis ground (−):

RHD model

(B225) No. 24 (+) — Chassis ground (−):
(B225) No. 22 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Check the following item and repair or replace if necessary.

• Blown out of fuse

• Open circuit in harness between starter relay and ignition switch connector

• Poor contact of ignition switch connector

8.CHECK STARTER RELAY.

1) Connect the battery to starter relay terminals No. 11 and No. 12 (LHD model) or No. 22 and No. 23 (RHD model).

2) Measure the resistance between starter relay terminals.

Terminals

LHD model

No. 9 — No. 10:

RHD model

No. 24 — No. 25:

Is the resistance less than 1 Ω?

Replace the starter relay.

9.CHECK HARNESS BETWEEN STARTER RELAY CONNECTOR AND STARTER MOTOR.

Measure the resistance of harness between starter relay connector and starter motor.

Connector & terminal

LHD model

(B225) No. 10 — (B14) No. 1:

RHD model

(B225) No. 25 — (B14) No. 1:

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 starter relay connector and starter motor

• Poor contact of OP joint connector (RHD model)

10.CHECK HARNESS BETWEEN ECM AND STARTER RELAY CONNECTOR.

1) Turn the ignition switch to OFF.

2) Disconnect the connector from ECM.

3) Measure the resistance of harness between ECM connector and starter relay connector.

Connector & terminal

LHD model

(B134) No. 36 — (B225) No. 12:
(B135) No. 20 — (B225) No. 10:

RHD model

(B134) No. 36 — (B225) No. 23:
(B135) No. 20 — (B225) No. 25:

Is the resistance less than 1 Ω?

Check the engine control module (ECM) power supply and ground line.

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit of harness between ECM connector and starter relay connector

• Poor contact of short connector (RHD model)

2. MODEL WITH PUSH BUTTON START

CAUTION:

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

WIRING DIAGRAM:

STEPCHECKYESNO

1.CHECK BATTERY.

Check the battery voltage.

Is the voltage 12 V or more?

Charge or replace the battery.

2.CHECK OPERATION OF STARTER MOTOR.

Does the starter motor operate?

3.CHECK DTC.

Is DTC displayed?

Check the appropriate DTC using the List of Diagnostic Trouble Code (DTC).

The circuit has returned to a normal condition at this time. Reproduce the failure, and then perform the diagnosis again.

NOTE:

In this case, temporary poor contact of connector may be the cause.

4.CHECK PUSH BUTTON IGNITION SWITCH.

Press the push button ignition switch twice with the ignition OFF (ACC OFF).

NOTE:

Release the clutch pedal.

Does the ignition turn to ON?

Check the push button start system.

5.CHECK PUSH BUTTON IGNITION SWITCH.

1) Depress the clutch pedal.

2) Check the push button ignition switch indicator.

Does the indicator turn to green?

Check the following item and repair or replace if necessary.

• Blown-out of fuse (F/B No. 21)

• Open or ground short circuit of harness between battery and clutch start switch connector

• Open circuit or short circuit to ground in harness between clutch start switch connector and power supply CM

• Poor contact of clutch start switch

6.CHECK CLUTCH SWITCH SIGNAL FOR SMART.

1) Read the data of clutch switch signal for smart using Subaru Select Monitor.

NOTE:

For detailed operation procedures, refer to “READ CURRENT DATA FOR ENGINE”.

2) Depress the clutch pedal.

Does the data of clutch switch signal for smart turn to ON?

Repair the open circuit of harness between ECM connector and clutch start switch connector.

7.CHECK START SWITCH SIGNAL.

1) Read the waveform of start switch signal using Subaru Select Monitor.

NOTE:

For detailed operation procedures, refer to “READ CURRENT DATA FOR ENGINE”.

2) Press the push button ignition switch once with the clutch pedal depressed.

Does waveforms of the start switch signal occur?

8.CHECK HARNESS BETWEEN ECM AND POWER SUPPLY CM.

1) Turn the ignition to OFF.

2) Disconnect the connectors from ECM and power supply CM.

3) Measure the resistance of harness between ECM connector and power supply CM.

Connector & terminal

(B134) No. 27 — (B420) No. 39:

Is the resistance less than 1 Ω?

Repair the open circuit of harness between ECM connector and power supply CM connector.

9.CHECK HARNESS BETWEEN ECM AND POWER SUPPLY CM.

Measure the resistance between ECM connector and chassis ground.

Connector & terminal

(B134) No. 27 — Chassis ground:

Is the resistance 1 MΩ or more?

Repair the short circuit to ground in harness between ECM connector and power supply CM connector.

10.CHECK START SWITCH SIGNAL.

1) Connect the connector to ECM and power supply CM.

2) Read the waveform of start switch signal using an oscilloscope.

3) Press the push button ignition switch once with the clutch pedal depressed.

Connector & terminal

(B134) No. 27 (+) — Chassis ground (−):

Does waveforms of the start switch signal occur?

Repair the poor contact of ECM connector.

Repair the poor contact of power supply CM connector.

11.CHECK INPUT SIGNAL FOR STARTER MOTOR.

1) Turn the ignition to OFF.

2) Disconnect the connector from starter motor.

3) Place the shift lever in neutral.

4) Press the push button ignition switch once with the clutch pedal depressed.

5) Measure the voltage between the starter motor connector and the engine ground.

Connector & terminal

(B14) No. 1 (+) — Engine ground (−):

Is the voltage 10 V or more?

Check the starter motor.

12.CHECK IG RELAY 1 (PUSH BUTTON START) POWER SUPPLY.

1) Remove the IG relay 1 (push button start).

2) Turn the ignition to ON.

3) Measure the voltage between the IG relay 1 (push button start) connector and chassis ground.

Connector & terminal

(B425) No. 34 (+) — Chassis ground (−):

(B425) No. 36 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Check the following item and repair or replace if necessary.

• Blown out of fuse

• Open circuit or short circuit to ground in harness between IG relay 1 (push button start) connector and power supply CM

• Open circuit or short circuit to ground in harness between IG relay 1 (push button start) connector and battery

13.CHECK HARNESS BETWEEN IG RELAY 1 (PUSH BUTTON START) CONNECTOR AND CHASSIS GROUND.

1) Turn the ignition to OFF.

2) Measure the resistance of harness between the IG relay 1 (push button start) connector and chassis ground.

Connector & terminal

(B425) No. 35 — Chassis ground:

Is the resistance less than 5 Ω?

Repair the open circuit in harness between the IG relay 1 (push button start) connector and chassis ground.

14.CHECK IG RELAY 1 (PUSH BUTTON START).

1) Connect the battery to IG relay 1 (push button start) terminals No. 34 and No. 35.

2) Measure the resistance between IG relay 1 (push button start) terminals.

Terminals

No. 36 — No. 37:

Is the resistance less than 1 Ω?

Replace the IG relay 1 (push button start).

15.CHECK STARTER RELAY (PUSH BUTTON START) POWER SUPPLY.

1) Install the IG relay 1 (push button start).

2) Remove the starter relay (push button start).

3) Turn the ignition to ON.

4) Measure the voltage between starter relay (push button start) connector and chassis ground.

Connector & terminal

(B425) No. 22 (+) — Chassis ground (−):

(B425) No. 24 (+) — Chassis ground (−):

Is the voltage 10 V or more?

Check the following item and repair or replace if necessary.

• Blown-out of fuse (F/B No. 26)

• Open circuit or short circuit to ground in harness between starter relay (push button start) connector and IG relay 1 (push button start) connector

• Open circuit in harness between starter relay (push button start) connector and battery

16.CHECK HARNESS BETWEEN STARTER RELAY (PUSH BUTTON START) CONNECTOR AND CHASSIS GROUND.

1) Turn the ignition to OFF.

2) Measure the resistance of harness between starter relay (push button start) connector and chassis ground.

Connector & terminal

(B425) No. 23 — Chassis ground:

Is the resistance less than 5 Ω?

Repair the open circuit in harness between starter relay (push button start) connector and chassis ground.

17.CHECK STARTER RELAY (PUSH BUTTON START).

1) Connect the battery to starter relay (push button start) terminals No. 22 and No. 23.

2) Measure the resistance between starter relay (push button start) terminals.

Terminals

No. 24 — No. 25:

Is the resistance less than 1 Ω?

Replace the starter relay (push button start).

18.CHECK HARNESS BETWEEN STARTER RELAY (PUSH BUTTON START) CONNECTOR AND STARTER CUT RELAY CONNECTOR.

1) Remove the starter cut relay.

2) Measure the resistance of harness between starter relay (push button start) connector and starter cut relay connector.

Connector & terminal

(B425) No. 25 — (B425) No. 1:

(B425) No. 25 — (B425) No. 5:

Is the resistance less than 1 Ω?

Repair the open circuit in harness between starter relay (push button start) connector and starter cut relay connector.

19.CHECK HARNESS BETWEEN ECM AND STARTER CUT RELAY CONNECTOR.

1) Disconnect the connector from ECM.

2) Measure the resistance between starter cut relay and chassis ground.

Connector & terminal

(B425) No. 3 — Chassis ground:

Is the resistance 1 MΩ or more?

Repair the short circuit to ground in harness between ECM connector and starter cut relay connector.

20.CHECK STARTER CUT RELAY.

Measure the resistance between starter cut relay terminals.

Terminals

No. 2 — No. 5:

Is the resistance less than 1 Ω?

Replace the starter cut relay.

21.CHECK HARNESS BETWEEN STARTER CUT RELAY CONNECTOR AND STARTER RELAY CONNECTOR.

Measure the resistance of harness between starter cut relay connector and starter relay connector.

Connector & terminal

LHD model

(B425) No. 2 — (B225) No. 10:

RHD model

(B425) No. 2 — (B225) No. 24:

Is the resistance less than 1 Ω?

Repair the open circuit in harness between starter cut relay connector and starter relay connector.

22.CHECK HARNESS BETWEEN ECM AND STARTER RELAY CONNECTOR.

Measure the resistance of harness between ECM connector and starter relay connector.

Connector & terminal

LHD model

(B134) No. 36 — (B225) No. 11:
(B135) No. 20 — (B225) No. 9:

RHD model

(B134) No. 36 — (B225) No. 23:
(B135) No. 20 — (B225) No. 25:

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 connector and starter relay connector

• Poor contact of short connector (RHD model)

• Poor contact of OP joint connector (RHD model)

23.CHECK STARTER RELAY.

1) Connect the battery to starter relay terminals No. 11 and No. 12 (LHD model) or No. 22 and No. 23 (RHD model).

2) Measure the resistance between starter relay terminals.

Terminals

LHD model

No. 9 — No. 10:

RHD model

No. 24 — No. 25:

Is the resistance less than 1 Ω?

Replace the starter relay.

24.CHECK HARNESS BETWEEN STARTER RELAY CONNECTOR AND CLUTCH START SWITCH CONNECTOR.

Measure the resistance of harness between starter relay connector and clutch start switch connector.

Connector & terminal

LHD model

(B225) No. 12 — (B106) No. 2:

RHD model

(B225) No. 22 — (B106) No. 2:

Is the resistance less than 1 Ω?

Repair the open circuit in harness between starter relay connector and clutch start switch connector.

25.CHECK HARNESS BETWEEN STARTER RELAY CONNECTOR AND STARTER MOTOR.

Measure the resistance of harness between starter relay connector and starter motor.

Connector & terminal

LHD model

(B225) No. 9 — (B14) No. 1:

RHD model

(B225) No. 25 — (B14) No. 1:

Is the resistance less than 1 Ω?

Check the engine control module (ECM) power supply and ground line.

Repair the harness and connector.

NOTE:

In this case, repair the following item:

• Open circuit in harness between starter relay connector and starter motor

• Poor contact of OP joint connector (RHD model)