Nissan Frontier D22. Manual - part 399

POWER SUPPLY CIRCUIT FOR ECM

EC-699

[VG33E]

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2. 

CHECK ECM POWER SUPPLY CIRCUIT-I

1.

Turn ignition switch OFF and then ON.

2.

Check voltage between ECM terminal 24 and ground with CON-
SULT-II or tester.

OK or NG

OK

>> GO TO 4.

NG

>> GO TO 3.

3. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors E43, M65

●

Harness connectors M5, F27

●

Fuse block (J/B) connector E49

●

10A fuse

●

Harness for open or short between ECM and fuse

>> Repair harness or connectors.

4. 

CHECK ECM GROUND CIRCUIT-I FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between ECM terminals 10, 19, 25, 32, 116, 124 and engine ground.
Refer to WIRING DIAGRAM.

4.

Also check harness for short to power.

OK or NG

OK

>> GO TO 15.

NG

>> GO TO 5.

5. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness for open between ECM and engine ground

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

Voltage: Battery voltage

SEF674U

Continuity should exist.

EC-700

[VG33E]

POWER SUPPLY CIRCUIT FOR ECM

6. 

CHECK ECM POWER SUPPLY CIRCUIT-II

1.

Stop engine.

2.

Check voltage between ECM terminal 80 and ground with CON-
SULT-II or tester.

OK or NG

OK

>> GO TO 8.

NG

>> GO TO 7.

7. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness connectors M81, F36

●

Fuse block (J/B) connector M27

●

10A fuse

●

Harness for open or short between ECM and fuse

>> Repair harness or connectors.

8. 

CHECK ECM POWER SUPPLY CIRCUIT-III

1.

Turn ignition switch ON and then OFF.

2.

Check voltage between ECM terminals 67, 72, 117 and ground
with CONSULT-II or tester.

OK or NG

OK

>> GO TO 14.

NG (Battery voltage does not exist.)>>GO TO 9.
NG (Battery voltage exists for more than a few seconds.)>>GO  TO

13.

Voltage: Battery voltage

SEF678U

Voltage

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

SEF679U

POWER SUPPLY CIRCUIT FOR ECM

EC-701

[VG33E]

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9. 

CHECK ECM POWER SUPPLY CIRCUIT-IV

1.

Disconnect ECM relay.

2.

Check voltage between terminals 2, 5 and ground with CON-
SULT-II or tester.

OK or NG

OK

>> GO TO 11.

NG

>> GO TO 10.

10. 

DETECT MALFUNCTIONING PART

Check the following.

●

Harness for open or short between ECM relay and harness connectors M59, F27

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

11. 

CHECK ECM OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT

1.

Disconnect ECM harness connector.

2.

Check harness continuity between ECM terminal 4 and ECM relay terminal 1.
Refer to WIRING DIAGRAM.

3.

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

OK or NG

OK

>> GO TO 12.

NG

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

12. 

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

1.

Check harness continuity between ECM terminals 67, 72, 117 and ECM relay terminal 3.
Refer to WIRING DIAGRAM.

2.

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

OK or NG

OK

>> GO TO 13.

NG

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

LEC106A

Voltage: Battery voltage

SEF625W

Continuity should exist.

Continuity should exist.

EC-702

[VG33E]

POWER SUPPLY CIRCUIT FOR ECM

13. 

CHECK ECM RELAY

1.

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

2.

Check continuity between relay terminals 3 and 5.

OK or NG

OK

>> GO TO 14.

NG

>> Replace ECM relay.

14. 

CHECK ECM GROUND CIRCUIT-II FOR OPEN AND SHORT

1.

Turn ignition switch OFF.

2.

Disconnect ECM harness connector.

3.

Check harness continuity between ECM terminals 10, 19, 25, 32, 116, 124 and engine ground.
Refer to WIRING DIAGRAM.

4.

Also check harness for short to power.

OK or NG

OK

>> GO TO 15.

NG

>> GO TO 5.

15. 

CHECK INTERMITTENT INCIDENT

Refer to 

EC-696, "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT"

 .

>> INSPECTION END.

12V (1 - 2) applied

: Continuity exists.

No voltage applied

: No continuity

SEF090M

Continuity should exist.