Nissan Frontier D22. Manual - part 372

PRECAUTIONS

EC-591

[VG33E]

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Precautions

UBS00DEH

LEC027A

EC-592

[VG33E]

PRECAUTIONS

●

Always use a 12 volt battery as power source.

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Do not attempt to disconnect battery cables while engine is
running.

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Before connecting or disconnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative
battery terminal. Failure to do so may damage the ECM
because battery voltage is applied to ECM even if ignition
switch is turned off.

●

Before removing parts, turn ignition switch OFF and then
disconnect battery ground cable.

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Do not disassemble ECM.

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If a battery terminal is disconnected, the memory will return
to the ECM value.
The ECM will not start to self-control at its initial value.
Engine operation can vary slightly when the terminal is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not replace parts because of a slight variation.

●

When connecting ECM harness connector, tighten securing
bolt until the gap between orange indicators disappears.

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When connecting or disconnecting pin connectors into or
from ECM, take care not to damage pin terminals (bend or
break).
Make sure that there are not any bends or breaks on ECM
pin terminal, when connecting pin connectors.

●

Securely connect ECM harness connectors.
A poor connection can cause an extremely high (surge)
voltage to develop in coil and condenser, thus resulting in
damage to ICs.

●

Keep engine control system harness at least 10 cm (4 in)
away from adjacent harness, to prevent engine control sys-
tem malfunctions due to receiving external noise, degraded
operation of ICs, etc.

●

Keep engine control system parts and harness dry.

SEF289H

SEF707Y

: 3 - 5 N·m (0.3 - 0.5 kg-m, 26 - 43 in-lb)

SEF308Q

SEF291H

PRECAUTIONS

EC-593

[VG33E]

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Before replacing ECM, perform ECM Terminals and Refer-
ence Value inspection and make sure ECM functions prop-
erly. Refer to 

EC-667, "ECM Terminals and Reference Value"

.

●

Handle mass air flow sensor carefully to avoid damage.

●

Do not disassemble mass air flow sensor.

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Do not clean mass air flow sensor with any type of deter-
gent.

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Even a slight leak in the air intake system can cause seri-
ous incidents.

●

Do not shock or jar the camshaft position sensor’ crank-
shaft position sensor (OBD).

●

After performing each TROUBLE DIAGNOSIS, perform DTC
Confirmation Procedure or Overall Function Check.
The DTC should not be displayed in the DTC Confirmation
Procedure if the repair is completed. The Overall Function
Check should be a good result if the repair is completed. 

●

When measuring ECM signals with a circuit tester, never
allow the two tester probes to contact.
Accidental contact of probes will cause a short circuit and
damage the ECM power transistor.

●

Do not use ECM ground terminals when measuring input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use a ground other than the ECM terminals,
such as the ground.

MEF040D

SEF217U

SEF348N

EC-594

[VG33E]

PRECAUTIONS

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B1 indicates the bank 1, B2 indicates the bank 2 as shown
in the figure.

Wiring Diagrams and Trouble Diagnosis

UBS00DEI

When you read Wiring diagrams, refer to the following:

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GI-13, "How to Read Wiring Diagrams"

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PG-9, "POWER SUPPLY ROUTING"

When you perform trouble diagnosis, refer to the following:

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GI-9, "HOW TO FOLLOW TEST GROUPS IN TROUBLE DIAGNOSES"

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GI-25, "How to Perform Efficient Diagnosis for an Electrical Incident"

SEC893C