Infiniti M45 (Y34). Manual - part 362

POWER SUPPLY AND GROUND CIRCUIT

EC-137

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4. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten two ground screws. 
Refer to 

EC-141, "Ground Inspection"

 .

OK or NG

OK

>> GO TO 5.

NG

>> Repair or replace ground connections.

5. 

CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I

1.

Disconnect ECM harness connector.

2.

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

3.

Also check harness for short to power.

OK or NG

OK

>> GO TO 7.

NG

>> GO TO 6.

6. 

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.

PBIB1118E

Continuity should exist.

EC-138

POWER SUPPLY AND GROUND CIRCUIT

7. 

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 9.

NG

>> GO TO 8.

8. 

DETECT MALFUNCTIONING PART

Check the following.

●

10A fuse

●

20A fuse

●

Fuse block (J/B) No. 2 connector E215

●

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

●

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.

9. 

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 11.

NG

>> GO TO 10.

10. 

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.

PBIB0040E

Voltage

:Battery voltage

PBIB0071E

Continuity should exist.

POWER SUPPLY AND GROUND CIRCUIT

EC-139

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11. 

CHECK ECM RELAY

Refer to 

EC-142, "Component Inspection"

 .

OK or NG

OK

>> Go to 

EC-649, "IGNITION SIGNAL"

 .

NG

>> Replace ECM relay.

12. 

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 18.

NG (Battery voltage does not exist.)>>GO TO 13.
NG (Battery voltage exists for more than a few seconds.)>>GO TO 15.

13. 

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 15.

NG

>> GO TO 14.

Voltage:

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

PBIB1875E

PBIB0040E

Voltage:

Battery voltage

PBIB0074E

EC-140

POWER SUPPLY AND GROUND CIRCUIT

14. 

DETECT MALFUNCTIONING PART

Check the following;

●

10A fuse

●

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.

15. 

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

1.

Disconnect ECM harness connector.

2.

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

3.

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

OK or NG

OK

>> GO TO 17.

NG

>> GO TO 16.

16. 

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.

17. 

CHECK ECM RELAY

Refer to 

EC-142, "Component Inspection"

 .

OK or NG

OK

>> GO TO 18.

NG

>> Replace ECM relay.

18. 

CHECK GROUND CONNECTIONS

1.

Turn ignition switch OFF.

2.

Loosen and retighten two ground screws. 
Refer to 

EC-141, "Ground Inspection"

 .

OK or NG

OK

>> GO TO 19.

NG

>> Repair or replace ground connections.

ECM terminal

ECM relay terminal

12

3

163, 166

6

Continuity should exist.

PBIB1118E