Infiniti F50. Manual - part 374

POWER SUPPLY CIRCUIT FOR ECM

EC-137

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4. 

CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I

1.

Turn ignition switch “OFF”.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between ECM terminals 156, 159, 165, 168 and engine ground.
Refer to Wiring Diagram.

4.

Also check harness for short to power.

OK or NG

OK

>> GO TO 6.

NG

>> GO TO 5.

5. 

DETECT MALFUNCTIONING PART

Check the following.

●

Joint connector-29

●

Harness for open or short between ECM and ground

>> Repair open circuit or short to power in harness or connectors.

6. 

CHECK POWER SUPPLY-II

1.

Disconnect ECM relay.

2.

Check voltage between ECM relay terminals 2, 5 and ground
with CONSULT-II or tester.

OK or NG

OK

>> GO TO 8.

NG

>> GO TO 7.

Continuity should exist.

PBIB0040E

PBIB0071E

EC-138

POWER SUPPLY CIRCUIT FOR ECM

7. 

DETECT MALFUNCTIONING PART

Check the following.

●

10A fuse

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20A fuse

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Fuse block (J/B) No. 2 connector E215

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Fuse, fusible link and relay block (J/B) connector E3

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Harness for open or short between ECM relay and battery

>> Repair open circuit or short to ground or short to power in harness or connectors.

8. 

CHECK OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Check harness continuity between ECM terminal 42 and ECM relay terminal 1.
Refer to Wiring Diagram.

2.

Also check harness for short to ground and short to power.

OK or NG

OK

>> Go to 

EC-641, "IGNITION SIGNAL"

 .

NG

>> GO TO 9.

9. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M135, F105

●

Fuse block (J/B) No. 2 connector M143

●

Harness for open or short between ECM relay and ECM

>> Repair open circuit or short to ground or short to power in harness or connectors.

10. 

CHECK ECM POWER SUPPLY CIRCUIT-III

1.

Turn ignition switch “ON” and then “OFF”.

2.

Check voltage between ECM terminals 12, 163, 166 and ground
with CONSULT-II or tester.

OK or NG

OK

>> GO TO 16.

NG (Battery voltage does not exist.)>>GO TO 11.
NG (Battery voltage exists for more than a few seconds.)>>GO TO 13.

Continuity should exist.

Voltage:

After turning ignition switch "OFF", battery 
voltage will exist for a few seconds, then 
drop approximately 0V.

PBIB1875E

POWER SUPPLY CIRCUIT FOR ECM

EC-139

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11. 

CHECK ECM POWER SUPPLY CIRCUIT-IV

1.

Disconnect ECM relay.

2.

Check voltage between ECM relay terminal 7 and ground with
CONSULT-II or tester.

OK or NG

OK

>> GO TO 13.

NG

>> GO TO 12.

12. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness for open or short between ECM relay and 10A fuse

>> Repair open circuit or short to ground or short to power in harness or connectors.

13. 

CHECK HARNESS CONTINUITY BETWEEN ECM RELAY AND ECM FOR OPEN AND SHORT

1.

Check harness continuity between ECM terminals and ECM relay terminals as follows.
Refer to Wiring Diagram.

2.

Also check harness for short to ground and short to power.

OK or NG

OK

>> GO TO 15.

NG

>> GO TO 14.

14. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M135, F105

●

Fuse block (J/B) No. 2 connector M143

●

Harness for open or short between ECM and ECM relay

>> Repair open circuit or short to ground or short to power in harness or connectors.

PBIB0040E

Voltage:

Battery voltage

PBIB0074E

ECM terminal

ECM relay terminal

12

3

163, 166

6

Continuity should exist.

EC-140

POWER SUPPLY CIRCUIT FOR ECM

15. 

CHECK ECM RELAY

Refer to 

EC-140, "Component Inspection"

 .

OK or NG

OK

>> GO TO 16.

NG

>> Replace ECM relay.

16. 

CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-II

1.

Turn ignition switch “OFF”.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between ECM terminals 156, 159, 165, 168 and engine ground.
Refer to Wiring Diagram.

4.

Also check harness for short to power.

OK or NG

OK

>> GO TO 18.

NG

>> GO TO 17.

17. 

DETECT MALFUNCTIONING PART

Check the following.

●

Joint connector-29

●

Harness for open or short between ECM and ground

>> Repair open circuit or short to power in harness or connectors.

18. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-132, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END

Component Inspection

EBS00LWI

ECM RELAY

1.

Apply 12V direct current between ECM relay terminals 1 and 2.

2.

Check continuity between relay terminals 3 and 5, 6 and 7.

3.

If NG, replace ECM relay.

Continuity should exist.

Condition

Continuity

12V direct current supply between
terminals 1 and 2

Yes

OFF

No

PBIB0077E