NISSAN X-TRAIL 2003 Electronic Repair Manual

GI-28
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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.
lConnect one probe of the DMM to a known good ground.
lBegin probing at one end of the circuit and work your way to the other end.
lWith SW1 open, probe at SW1 to check for voltage.
voltage; open is further down the circuit than SW1.
no voltage; open is between fuse block and SW1 (point A).
lClose 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).
lClose 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
lDisconnect the battery negative cable and remove the blown fuse.
lDisconnect all loads (SW1 open, relay disconnected and solenoid disconnected) powered through the
fuse.
lConnect one probe of the DMM to the load side of the fuse terminal. Connect the other probe to a known
good ground.
lWith 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.
lClose 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.
lClose 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
lRemove the blown fuse and disconnect all loads (i.e. SW1 open, relay disconnected and solenoid discon-
nected) powered through the fuse.
lTurn the ignition key to the ON or START position. Verify battery voltage at the battery + side of the fuse
terminal (one lead on the battery + terminal side of the fuse block and one lead on a known good ground).
SGI847-A

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
GI-29
lWith 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.
lWith 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.
lWith 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 drasti-
cally 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.
When inspecting a ground connection follow these rules:
lRemovethegroundboltorscrew.
lInspect all mating surfaces for tarnish, dirt, rust, etc.
lClean as required to assure good contact.
lReinstall bolt or screw securely.
lInspect for “add-on” accessories which may be interfering with the ground circuit.
lIf 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
eyelet 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:
lUndersized wiring (single strand example)
SGI853

GI-30
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
lCorrosion on switch contacts
lLoose wire connections or splices.
If repairs are needed always use wire that is of the same or larger gauge.
MEASURING VOLTAGE DROP — ACCUMULATED METHOD
lConnect 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.
lOperate the circuit.
lThe DMM will indicate how many volts are being used to “push” current through that part of the circuit.
Note in the illustration that there is an excessive 4.1 volt drop between the battery and the bulb.
MEASURING VOLTAGE DROP — STEP-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.
SGI974

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
GI-31
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.
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.
SAIA0258E
MGI034A
Pin
No.Item ConditionVoltage
value [V]In case of high resistance such as single strand [V] *
1SwitchSwitch ON Battery voltage Lower than battery voltage Approx. 8 (Example)
Switch OFF Approx. 0 Approx. 0
2LampSwitch ON Battery voltage Approx. 0 (Inoperative lamp)
Switch OFF Approx. 0 Approx. 0

GI-32
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 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.
Control Units and Electrical PartsEAS000G7
PRECAUTIONS
lNever reverse polarity of battery terminals.
lInstall only parts specified for a vehicle.
lBefore replacing the control unit, check the input and output and
functions of the component parts.
lDo not apply excessive force when disconnecting a connector.
lIf a connector is installed by tightening bolts, loosen bolt mount-
ing it, then take it out by hand.
lBefore installing a connector, make sure the terminal is not bent
or damaged, and then correctly connect it.
When installing a connector by tightening bolts, fix it by tighten-
ing the mounting bolt until the painted projection of the connec-
tor becomes even with the surface.
MGI035A
Pin
No.Item ConditionVo l ta g e
value [V]In case of high resistance such as single strand [V] *
1LampSwitch ON Approx. 0 Battery voltage (Inoperative lamp)
Switch OFF Battery voltage Battery voltage
2SwitchSwitch ON Approx. 0 Higher than 0 Approx. 4 (Example)
Switch OFF Approx. 5 Approx. 5
SAIA0251E
SAIA0252E

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
GI-33
lFor removal of the lever type connector, pull the lever up to the
direction pointed to by the arrow A in the figure, and then
remove the connector.
lFor installation of the lever type connector, pull down the lever to
the direction pointed by the arrow B in the figure, and then push
the connector until a clicking noise is heard.
lDo not apply excessive shock to the control unit by dropping or
hitting it.
lBe careful to prevent condensation in the control unit due to
rapid temperature changes and do not let water or rain get on it.
If water is found in the control unit, dry it fully and then install it in
the vehicle.
lBe careful not to let oil to get on the control unit connector.
lAvoid cleaning the control unit with volatile oil.
lDo not disassemble the control unit, and do not remove the
upper and lower covers.
SAIA0253E
SAIA0254E
SAIA0255E

GI-34
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
lWhen using a DMM, be careful not to let test probes get close to
each other to prevent the power transistor in the control unit
from damaging battery voltage because of short circuiting.
lWhen checking input and output signals of the control unit, use
the specified check adapter.
SMJ INSTALLATION
To install SMJ, tighten bolts until orange “fulltight” mark appears and
then retighten to specified torque as required.
CAUTION:
Do not overtighten bolts, otherwise, they may be damaged.
SEF348N
:3 - 5 N-m (0.3 - 0.5 kg-m, 26 - 43 in-lb)
CEL969

CONSULT-II CHECKING SYSTEM
GI-35
CONSULT-II CHECKING SYSTEMPFP:00000
DescriptionEAS000G8
lCONSULT-II is a hand-held type tester. When it is connected with a diagnostic connector equipped on the
vehicle side, it will communicate with the control unit equipped in the vehicle and then enable various
kinds of diagnostic tests.
lRefer to “CONSULT-II Software Operation Manual” for more information.
Function and System ApplicationEAS000G9
x:Applicable
*1: Nissan Anti-Theft System
Nickel Metal Hydride Battery ReplacementEAS000GA
CONSULT-II contains a nickel metal hydride battery. When replacing the battery obey the following:
WA RN ING:
Replace the nickel metal hydride battery with Genuine CONSULT-II battery only. Use of another bat-
tery may present a risk of fire or explosion. The battery may present a fire or chemical burn hazard if
mistreated. Do not recharge, disassemble or dispose of in fire.
Keep the battery out of reach of children and discard used battery conforming to the local regulations.
Checking EquipmentEAS000GB
When ordering the following equipment, contact your NISSAN/INFINITI distributor.
Diagnostic test
modeFunction
ENGINE
A/T
AIR BAG
ESP (Including ABS)
ALL MODE 4WD
NATS*1
Work supportThis mode enables a technician to adjust some devices faster and more accu-
rately by following the indications on CONSULT-II.x- -x- -
Self-diagnostic
resultsSelf-diagnostic results can be read and erased quickly. x x x x x x
Trouble diagnos-
tic recordCurrent self-diagnostic results and all trouble diagnostic records previously stored
can be read.--x- - -
Data monitor Input/Output data in the ECM can be read. x x - x x -
Active testDiagnostic Test Mode in which CONSULT-II drives some actuators apart from the
ECMs and also shifts some parameters in a specified range.x- -x- -
DTC confirmationThe results of SRT (System Readiness Test) and the self-diagnosis status/result
can be confirmed.x- -- - -
DTC work sup-
portSelect the operating condition to confirm Diagnosis Trouble Codes. - x - - - -
ECM part number ECM part number can be read. x x - x x -
ECU discrimi-
nated No.Classification number of a replacement ECU can be read to prevent an incorrect
ECU from being installed.--x- - -
Function testConducted by CONSULT-II instead of a technician to determine whether each
system is “OK” or “NG”.xxxx - -
Control unit initial-
izationAll registered ignition key IDs in NATS components can be initialized and new IDs
can be registered.---- - x
Self-function
checkECM checks its own NATS communication interface. - - - - - x

GI-36
CONSULT-II CHECKING SYSTEM
NOTE:
lThe CONSULT-II must be used in conjunction with a program card.
CONSULT-II does not require loading (Initialization) procedure.
lBe sure the CONSULT-II is turned off before installing or removing a program card.
CONSULT-II Data Link Connector (DLC) CircuitEAS000GC
INSPECTION PROCEDURE
If the CONSULT-II cannot diagnose the system properly, check the following items.
To o l n a m eDescription
NISSAN CONSULT-II
1. CONSULT-II unit (Tester internal soft:
Resident version 3.2.0) and accessories
2. Program card AED01A and AEN00A (For
NATS)
To confirm the best combination of these
softwares, refer to CONSULT-II Operation
Manual.
SGI083A
SGI125A
Symptom Check item
CONSULT-II cannot access
any system.
lCONSULT-II DLC power supply circuit (Terminal 7) and ground circuit (Terminal 8) (For detailed
circuit, refer to “MIL & Data Link Connectors Wiring Diagram” in EC section.)
lCONSULT-II DLC cable
CONSULT-II cannot access
individual system. (Other sys-
tems can be accessed.)
lCONSULT-II program card (Check the appropriate CONSULT-II program card for the system.
Refer to "Checking Equipment".)
lPower supply and ground circuit for the control unit of the system (For detailed circuit, refer to wir-
ing diagram for each system.)
lOpen or short circuit between the system and CONSULT-II DLC (For detailed circuit, refer to wiring
diagram for each system.)

LIFTING POINT
GI-37
LIFTING POINTPFP:00000
Special Service ToolsEAS000FH
CAUTION:
lEvery time the vehicle is lifted up, maintain the complete vehicle curb condition.
lSince the vehicle's center of gravity changes when removing main parts on the front side (engine,
transmission, suspension etc.), support a jack up point on the rear side garage jack with a mission
jack or equivalent.
lSince the vehicle's center of gravity changes when removing main parts on the rear side (rear axle,
suspension, etc.), support a jack up point on the front side garage jack with a mission jack or
equivalent.
lBe careful not to smash or do not do anything that would affect piping parts.
Garage Jack and Safety StandEAS000FI
WA RN ING:
lPark the vehicle on a level surface when using the jack. Make sure to avoid damaging pipes,
tubes, etc. under the vehicle.
lNever get under the vehicle while it is supported only by the jack. Always use safety stands when
you have to get under the vehicle.
Tool number
To o l n a m eDescription
LM4086-0200
Board on lift attachment
LM4519-0000
Safety stand attachment
S-NT001
S-NT002