2003 NISSAN TEANA Power

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
GI-27
C
D
E
F
G
H
I
J
K
L
MB
GI

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.
CIRCUIT INSPECTION
Introduction
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 har-
ness or electrical component to do this.
NOTE:
Refer to “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
portion 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 cir-
cuit has good continuity. If there were an open in the circuit, the DMM would indicate an over limit or infi-
nite resistance 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
infinite resistance condition. (point C)
Any circuit can be diagnosed using the approach in the previous example.
OPEN A circuit is open when there is no continuity through a section of the circuit.
SHORTThere are two types of shorts.

SHORT CIRCUITWhen 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.
SGI846-A

GI-28
SERVICE INFORMATION FOR ELECTRICAL INCIDENT

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.
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
terminal (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).
SGI847-A

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
GI-29
C
D
E
F
G
H
I
J
K
L
MB
GI

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 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:

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
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:

Undersized wiring (single strand example)

Corrosion on switch contacts

Loose wire connections or splices.
SGI853

GI-30
SERVICE INFORMATION FOR ELECTRICAL INCIDENT

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.
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.
The step by step voltage drop test can identify a component or wire with too much resistance.
SGI974
SAIA0258E

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
GI-31
C
D
E
F
G
H
I
J
K
L
MB
GI

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.
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 PartsBAS0007J
PRECAUTIONS

Never reverse polarity of battery terminals.

Install only parts specified for a vehicle.

Before replacing the control unit, check the input and output and functions of the component parts.

Do not apply excessive force when disconnecting a connector.
MGI034A
Pin
No.Item ConditionVoltage
value [V]In case of high resistance such as single strand [V] *
1 SwitchSwitch 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
MGI035A
Pin
No.Item ConditionVoltage
value [V]In case of high resistance such as single strand [V] *
1 LampSwitch 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

GI-32
SERVICE INFORMATION FOR ELECTRICAL INCIDENT


Do not apply excessive shock to the control unit by dropping or
hitting it.

Be 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.

Be careful not to let oil to get on the control unit connector.

Avoid cleaning the control unit with volatile oil.

Do not disassemble the control unit, and do not remove the
upper and lower covers.

When 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.

When checking input and output signals of the control unit, use
the specified check adapter.
SAIA0255E
SEF348N

CONSULT-II CHECKING SYSTEM
GI-35
C
D
E
F
G
H
I
J
K
L
MB
GI

4. Touch necessary system on “SELECT SYSTEM” screen.
If necessary system is not indicated, check power supply and
ground of system control unit. If it is normal, refer to GI-35,
"CONSULT-II Data Link Connector (DLC) Circuit" .
5. Select the desired part to be diagnosed on the “SELECT DIAG
MODE” screen.
CONSULT-II Data Link Connector (DLC) CircuitBAS0007P
INSPECTION PROCEDURE
If the CONSULT-II cannot diagnose the system properly, check the following items.
NOTE:
The DDL1 and DDL2 circuits from DLC pins 12, 13, 14 and 15 may be connected to more than one system. A
short in a DDL circuit connected to a control unit in one system may affect CONSULT-II access to other sys-
tems.
BCIA0030E
BCIA0031E
Symptom Check item
CONSULT-II cannot access
any system.

CONSULT-II DLC power supply circuit (Terminal 8) and ground circuit (Terminal 4) (For detailed
circuit, refer to “MIL & Data Link Connectors Wiring Diagram” in EC section.)

CONSULT-II DLC cable and CONSULT-II CONVERTER
CONSULT-II cannot access
individual system. (Other sys-
tems can be accessed.)

CONSULT-II program card (Check the appropriate CONSULT-II program card for the system.
Refer to “Checking Equipment”.)

Power supply and ground circuit for the control unit of the system (For detailed circuit, refer to wir-
ing diagram for each system.)

Open or short circuit between the system and CONSULT-II DLC (For detailed circuit, refer to wiring
diagram for each system.)

Open or short circuit CAN communication line. Refer to LAN-49, "CAN System Specification Chart"
.

TOW TRUCK TOWING
GI-39
C
D
E
F
G
H
I
J
K
L
MB
GI

TOW TRUCK TOWINGPFP:00000
Tow Truck TowingBAS0007V
CAUTION:

All applicable local laws regarding the towing operation
must be obeyed.

It is necessary to use proper towing equipment to avoid
possible damage to the vehicle during towing operation.
Towing is in accordance with Towing Procedure Manual at
dealer.

Always attach safety chains before towing.

When towing, make sure that the transmission, steering
system and power train are in good order. If any unit is
damaged, dollies must be used.
NISSAN recommends that the vehicle be towed with the driving
(front) wheels off the ground as illustrated.
TOWING AN AUTOMATIC TRANSAXLE MODEL WITH THE FRONT WHEELS ON THE GROUND
CAUTION:
Never tow an automatic transaxle model with the front wheels on the ground as this will cause serious
and expensive damage to the transaxle.
Vehicle Recovery (Freeing a Stuck Vehicle) BAS0007W

Always pull the cable straight out from the front or rear of the
vehicle. Never pull on the vehicle at an angle.

Remove the front spoiler when you pull the vehicle forward. Oth-
erwise, the towing device may damage the spoiler.

Pulling devices such as ropes or canvas straps are not recom-
mended for use in vehicle towing or recovery.

Use the recovery hooks only, not other parts of the vehicle. Oth-
erwise, the vehicle body will be damaged.

Use the recovery hooks only to free a vehicle stuck in sand,
snow, mud, etc. Never tow the vehicle for a long distance using
only the recovery hooks.

The recovery hooks are under tremendous force when used to
free a stuck vehicle.

Stand clear of a stuck vehicle.
SGI805
PAIA0251E
PAIA0252E