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Nissan Pathfinder (2010 year). Manual - part 429

GI-38

< BASIC INSPECTION >

SERVICE INFORMATION FOR ELECTRICAL INCIDENT

lowing section illustrates ways to simulate the conditions/environment under which the owner experiences an

electrical incident.

The section is broken into the six following topics:

• Vehicle vibration

• Heat sensitive

• Freezing

• Water intrusion

• Electrical load

• Cold or hot start up

Get a thorough description of the incident from the customer. It is important for simulating the conditions of the

problem.

VEHICLE VIBRATION

The problem may occur or become worse while driving on a rough road or when engine is vibrating (idle with

A/C on). In such a case, you will want to check for a vibration related condition. Refer to the following illustra-

tion.

Connector & Harness

Determine which connectors and wiring harness would affect the electrical system you are inspecting. Gently

shake each connector and harness while monitoring the system for the incident you are trying to duplicate.

This test may indicate a loose or poor electrical connection.

Hint

Connectors can be exposed to moisture. It is possible to get a thin film of corrosion on the connector termi-

nals. A visual inspection may not reveal this without disconnecting the connector. If the problem occurs inter-

mittently, perhaps the problem is caused by corrosion. It is a good idea to disconnect, inspect and clean the

terminals on related connectors in the system.

Sensor & Relay

Gently apply a slight vibration to sensors and relays in the system you are inspecting.

This test may indicate a loose or poorly mounted sensor or relay.

Engine Compartment

There are several reasons a vehicle or engine vibration could cause an electrical complaint. Some of the

things to check for are:

• Connectors not fully seated.

• Wiring harness not long enough and is being stressed due to engine vibrations or rocking.

• Wires laying across brackets or moving components.

• Loose, dirty or corroded ground wires.

• Wires routed too close to hot components.

To inspect components under the hood, start by verifying the integrity of ground connections. (Refer to Ground

Inspection described later.) First check that the system is properly grounded. Then check for loose connection

by gently shaking the wiring or components as previously explained. Using the wiring diagrams inspect the

wiring for continuity.

Behind the Instrument Panel

An improperly routed or improperly clamped harness can become pinched during accessory installation. Vehi-

cle vibration can aggravate a harness which is routed along a bracket or near a screw.

Under Seating Areas

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SERVICE INFORMATION FOR ELECTRICAL INCIDENT

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< BASIC INSPECTION >

An unclamped or loose harness can cause wiring to be pinched by seat components (such as slide guides)

during vehicle vibration. If the wiring runs under seating areas, inspect wire routing for possible damage or

pinching.

HEAT SENSITIVE

• The customer's concern may occur during hot weather or after car

has sat for a short time. In such cases you will want to check for a

heat sensitive condition.

• To determine if an electrical component is heat sensitive, heat the

component with a heat gun or equivalent.

CAUTION:

Do not heat components above 60

C (140

• If incident occurs while heating the unit, either replace or properly

insulate the component.

FREEZING

• The customer may indicate the incident goes away after the car

warms up (winter time). The cause could be related to water freez-

ing somewhere in the wiring/electrical system.

• There are two methods to check for this. The first is to arrange for

the owner to leave his car overnight. Make sure it will get cold

enough to demonstrate his complaint. Leave the car parked out-

side overnight. In the morning, do a quick and thorough diagnosis

of those electrical components which could be affected.

• The second method is to put the suspect component into a freezer

long enough for any water to freeze. Reinstall the part into the car

and check for the reoccurrence of the incident. If it occurs, repair or

replace the component.

WATER INTRUSION

The incident may occur only during high humidity or in rainy/snowy

weather. In such cases the incident could be caused by water intru-

sion on an electrical part. This can be simulated by soaking the car

or running it through a car wash.

CAUTION:

Do not spray water directly on any electrical components.

ELECTRICAL LOAD

The incident may be electrical load sensitive. Perform diagnosis with

all accessories (including A/C, rear window defogger, radio, fog

lamps) turned on.

COLD OR HOT START UP

On some occasions an electrical incident may occur only when the car is started cold, or it may occur when

the car is restarted hot shortly after being turned off. In these cases you may have to keep the car overnight to

make a proper diagnosis.

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2010 Pathfinder

GI-40

< BASIC INSPECTION >

SERVICE INFORMATION FOR ELECTRICAL INCIDENT

Circuit Inspection

INFOID:0000000005255368

DESCRIPTION

• In general, testing electrical circuits is an easy task if it is approached in a logical and organized method.

Before beginning it is important to have all available information on the system to be tested. Also, get a thor-

ough understanding of system operation. Then you will be able to use the appropriate equipment and follow

the correct test procedure.

• You may have to simulate vehicle vibrations while testing electrical components. Gently shake the wiring

harness or electrical component to do this.

NOTE:

Refer to

GI-34, "How to Check Terminal"

to probe or check terminal.

TESTING FOR “OPENS” IN THE CIRCUIT

Before you begin to diagnose and test the system, you should rough sketch a schematic of the system. This

will help you to logically walk through the diagnosis process. Drawing the sketch will also reinforce your work-

ing knowledge of the system.

Continuity Check Method

The continuity check is used to find an open in the circuit. The digital multimeter (DMM) set on the resistance

function will indicate an open circuit as over limit (no beep tone or no ohms symbol). Make sure to always start

with the DMM at the highest resistance level.

To help in understanding the diagnosis of open circuits, please refer to the previous schematic.

• Disconnect the battery negative cable.

• Start at one end of the circuit and work your way to the other end. (At the fuse block in this example)

• Connect one probe of the DMM to the fuse block terminal on the load side.

• Connect the other probe to the fuse block (power) side of SW1. Little or no resistance will indicate that por-

tion of the circuit has good continuity. If there were an open in the circuit, the DMM would indicate an over

limit or infinite resistance condition. (point A)

• Connect the probes between SW1 and the relay. Little or no resistance will indicate that portion of the circuit

has good continuity. If there were an open in the circuit, the DMM would indicate an over limit or infinite resis-

tance condition. (point B)

• Connect the probes between the relay and the solenoid. Little or no resistance will indicate that portion of the

circuit has good continuity. If there were an open in the circuit, the DMM would indicate an over limit or infi-

nite resistance condition. (point C)

Any circuit can be diagnosed using the approach in the previous example.

Voltage Check Method

To help in understanding the diagnosis of open circuits please refer to the previous schematic.

In any powered circuit, an open can be found by methodically checking the system for the presence of voltage.

This is done by switching the DMM to the voltage function.

• Connect one probe of the DMM to a known good ground.

• Begin probing at one end of the circuit and work your way to the other end.

• With SW1 open, probe at SW1 to check for voltage.

voltage; open is further down the circuit than SW1.

OPEN

A circuit is open when there is no continuity through a section of the circuit.

SHORT

There are two types of shorts.

• SHORT CIRCUIT

When a circuit contacts another circuit and causes the normal resistance to
change.

• SHORT TO GROUND

When a circuit contacts a ground source and grounds the circuit.

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SERVICE INFORMATION FOR ELECTRICAL INCIDENT

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< BASIC INSPECTION >

no voltage; open is between fuse block and SW1 (point A).

• Close SW1 and probe at relay.

voltage; open is further down the circuit than the relay.

no voltage; open is between SW1 and relay (point B).

• Close the relay and probe at the solenoid.

voltage; open is further down the circuit than the solenoid.

no voltage; open is between relay and solenoid (point C).

Any powered circuit can be diagnosed using the approach in the previous example.

TESTING FOR “SHORTS” IN THE CIRCUIT

To simplify the discussion of shorts in the system, please refer to the following schematic.

Resistance Check Method

• Disconnect the battery negative cable and remove the blown fuse.

• Disconnect all loads (SW1 open, relay disconnected and solenoid disconnected) powered through the fuse.

• Connect one probe of the DMM to the load side of the fuse terminal. Connect the other probe to a known

good ground.

• With SW1 open, check for continuity.

continuity; short is between fuse terminal and SW1 (point A).

no continuity; short is further down the circuit than SW1.

• Close SW1 and disconnect the relay. Put probes at the load side of fuse terminal and a known good ground.

Then, check for continuity.

continuity; short is between SW1 and the relay (point B).

no continuity; short is further down the circuit than the relay.

• Close SW1 and jump the relay contacts with jumper wire. Put probes at the load side of fuse terminal and a

known good ground. Then, check for continuity.

continuity; short is between relay and solenoid (point C).

no continuity; check solenoid, retrace steps.

Voltage Check Method

• Remove the blown fuse and disconnect all loads (i.e. SW1 open, relay disconnected and solenoid discon-

nected) powered through the fuse.

• Turn the ignition key to the ON or START position. Verify battery voltage at the battery + side of the fuse ter-

minal (one lead on the battery + terminal side of the fuse block and one lead on a known good ground).

• With SW1 open and the DMM leads across both fuse terminals, check for voltage.

voltage; short is between fuse block and SW1 (point A).

no voltage; short is further down the circuit than SW1.

• With SW1 closed, relay and solenoid disconnected and the DMM leads across both fuse terminals, check for

voltage.

voltage; short is between SW1 and the relay (point B).

no voltage; short is further down the circuit than the relay.

• With SW1 closed, relay contacts jumped with fused jumper wire check for voltage.

voltage; short is down the circuit of the relay or between the relay and the disconnected solenoid (point C).

no voltage; retrace steps and check power to fuse block.

GROUND INSPECTION

• Ground connections are very important to the proper operation of electrical and electronic circuits. Ground

connections are often exposed to moisture, dirt and other corrosive elements. The corrosion (rust) can

become an unwanted resistance. This unwanted resistance can change the way a circuit works.

• Electronically controlled circuits are very sensitive to proper grounding. A loose or corroded ground can

drastically affect an electronically controlled circuit. A poor or corroded ground can easily affect the circuit.

Even when the ground connection looks clean, there can be a thin film of rust on the surface.

SGI847-A

2010 Pathfinder

GI-42

< BASIC INSPECTION >

SERVICE INFORMATION FOR ELECTRICAL INCIDENT

• When inspecting a ground connection follow these rules:

- Remove the ground bolt or screw.

- Inspect all mating surfaces for tarnish, dirt, rust, etc.

- Clean as required to assure good contact.

- Reinstall bolt or screw securely.

- Inspect for “add-on” accessories which may be interfering with the ground circuit.

- If several wires are crimped into one ground eyelet terminal, check for proper crimps. Make sure all of the

wires are clean, securely fastened and providing a good ground path. If multiple wires are cased in one eye-

let make sure no ground wires have excess wire insulation.

• For detailed ground distribution information, refer to “Ground Distribution” in PG section.

VOLTAGE DROP TESTS

• Voltage drop tests are often used to find components or circuits which have excessive resistance. A voltage

drop in a circuit is caused by a resistance when the circuit is in operation.

• Check the wire in the illustration. When measuring resistance with DMM, contact by a single strand of wire

will give reading of 0 ohms. This would indicate a good circuit. When the circuit operates, this single strand

of wire is not able to carry the current. The single strand will have a high resistance to the current. This will

be picked up as a slight voltage drop.

• Unwanted resistance can be caused by many situations as follows:

- Undersized wiring (single strand example)

- Corrosion on switch contacts

- Loose wire connections or splices.

• If repairs are needed always use wire that is of the same or larger gauge.

Measuring Voltage Drop — Accumulated Method

• Connect the DMM across the connector or part of the circuit you want to check. The positive lead of the

DMM should be closer to power and the negative lead closer to ground.

• Operate the circuit.

• The DMM will indicate how many volts are being used to “push” current through that part of the circuit.

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SERVICE INFORMATION FOR ELECTRICAL INCIDENT

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Note in the illustration that there is an excessive 4.1 volt drop between the battery and the bulb.

Measuring Voltage Drop — Steb-by-Step

• The step-by-step method is most useful for isolating excessive drops in low voltage systems (such as those

in “Computer Controlled Systems”).

• Circuits in the “Computer Controlled System” operate on very low amperage.

• The (Computer Controlled) system operations can be adversely affected by any variation in resistance in the

system. Such resistance variation may be caused by poor connection, improper installation, improper wire

gauge or corrosion.

• The step by step voltage drop test can identify a component or wire with too much resistance.

CONTROL UNIT CIRCUIT TEST

System Description

• When the switch is ON, the control unit lights up the lamp.

CASE 1

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2010 Pathfinder

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SERVICE INFORMATION FOR ELECTRICAL INCIDENT

INPUT-OUTPUT VOLTAGE CHART

• The voltage value is based on the body ground.
• *: If high resistance exists in the switch side circuit (caused by a single strand), terminal 1 does not detect battery voltage. Control unit

does not detect the switch is ON even if the switch does not turn ON. Therefore, the control unit does not supply power to light up the
lamp.

CASE 2

INPUT-OUTPUT VOLTAGE CHART

• The voltage value is based on the body ground.
• *: If high resistance exists in the switch side circuit (caused by a single strand), terminal 2 does not detect approx. 0V. Control unit

does not detect the switch is ON even if the switch does not turn ON. Therefore, the control unit does not control ground to light up the
lamp.

Terminal No.

Description

Condition

Value (Approx.)

In case of high resistance such as single
strand (V) *

−

Signal name

Input/

Output

Body
ground

Switch

Input

Switch ON

Battery voltage

Lower than battery voltage Approx. 8 (Ex-
ample)

Switch OFF

0 V

Approx. 0

Body
ground

Lamp

Output

Switch ON

Battery voltage

Approx. 0 (Inoperative lamp)

Switch OFF

0 V

Approx. 0

Terminal No.

Description

Condition

Value (Approx.)

In case of high resistance such as single
strand (V) *

−

Signal name

Input/

Output

Body
ground

Lamp

Output

Switch ON

Battery voltage (Inoperative lamp)

Switch OFF

Battery voltage

Body
ground

Switch

Input

Switch ON

0 V

Higher than 0 Approx. 4 (Example)

Switch OFF

5 V

Approx. 5

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2010 Pathfinder

CONSULT-III CHECKING SYSTEM

GI-45

< BASIC INSPECTION >

CONSULT-III CHECKING SYSTEM

Description

INFOID:0000000005255369

• When CONSULT-III is connected with a data link connector

equipped on the vehicle side, it will communicate with the control

unit equipped in the vehicle and then enable various kinds of diag-

nostic tests.

• Refer to “CONSULT-III Operation Manual” for more information.

Function and System Application

INFOID:0000000005255370

x : Applicable
*1: With Intelligent Key
*2:With automatic drive positioner
*3: With rearview camera
*4: With All Mode 4WD system

CONSULT-III Data Link Connector (DLC) Circuit

INFOID:0000000005255371

INSPECTION PROCEDURE

: Hood release handle

: Data link connector

ALBIA0047ZZ

Diagnostic test mode

Function

ENGINE

ANSMI

SSION

R BAG

IPDM

E/R

BCM

METER/

M&A

TELLIGENT KEY

AUT

DRIVE

POS.

VIE

CAMERA

MUL

ALL MODE

D/4WD

Work Support

This mode enables a technician to adjust some devices
faster and more accurately.

Self Diagnostic Result

Retrieve DTCs from ECU and display diagnostic items.

Data Monitor

Monitor the input/output signal of the control unit in real
time.

CAN Diagnosis

This mode displays a network diagnosis result about CAN
by a diagram.

CAN Diagnosis Support
Monitor

It monitors the status of CAN communication.

Active Test

Sends a drive signal from the CONSULT-III to the actua-
tor. The operation check can be performed.

DTC & SRT Confirma-
tion

The status of system monitoring tests and the self-diagno-
sis status/result can be confirmed.

ECU Identification

Displays the ECU identification number (part number etc.)
of the selected system.

Function Test

This mode can show results of self-diagnosis of ECU with
either “OK” or “NG”. For engine, more practical tests re-
garding sensors/switches and/or actuators are available.

Configuration

Function to READ/WRITE vehicle configuration.

Special Function

Other results or histories, etc. that are recorded in ECU
are displayed.

2010 Pathfinder

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