NISSAN TEANA 2008 Service Manual

GI-38
< BASIC INSPECTION >
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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.
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
SGI846-A

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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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.
 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.
SGI847-A

GI-40
< BASIC INSPECTION >
SERVICE INFORMATION FOR ELECTRICAL INCIDENT
 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.
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.
SGI853
SGI974

SERVICE INFORMATION FOR ELECTRICAL INCIDENT
GI-41
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 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
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
Terminal No. Description
Condition Value (Approx.)In case of high resistance such as single
strand (V) *
+−Signal nameInput/
Output
1Body
groundSwitch InputSwitch ON Battery voltageLower than battery voltage Approx. 8 (Ex-
ample)
Switch OFF 0 V Approx. 0
2Body
groundLamp OutputSwitch ON Battery voltage Approx. 0 (Inoperative lamp)
Switch OFF 0 V Approx. 0
MGI034A

GI-42
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SERVICE INFORMATION FOR ELECTRICAL INCIDENT
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 nameInput/
Output
1Body
groundLamp OutputSwitch ON 0V Battery voltage (Inoperative lamp)
Switch OFF Battery voltage Battery voltage
2Body
groundSwitch InputSwitch ON 0 V Higher than 0 Approx. 4 (Example)
Switch OFF 5 V Approx. 5
MGI035A

CONSULT-III/GST CHECKING SYSTEM
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PCONSULT-III/GST CHECKING SYSTEM
DescriptionINFOID:0000000003852797
 When CONSULT-III/GST is connected with a data link connector
(A) equipped on the vehicle side, it will communicate with the con-
trol unit equipped in the vehicle and then enable various kinds of
diagnostic tests.
 Refer to “CONSULT-III Software Operation Manual” for more infor-
mation.
CONSULT-III Function and System Application*1INFOID:0000000003852798
x: Applicable
*1: If GST application is equipped, functions in accordance with SAE J1979 and ISO 15031-5 can be used.
CONSULT-III/GST Data Link Connector (DLC) CircuitINFOID:0000000003852799
INSPECTION PROCEDURE
If the CONSULT-III/GST cannot diagnose the system properly, check the following items.
1 : Instrument driver lower panel
JPAIA0313GB
Diagnostic test mode Function
ENGINE
TRANSMISSION
AIR BAG
METER/M&A
BCM
AUTO DRIVE POS.
ABS
ABS (Including VDC)
IPDM E/R
HEAD LAMP LEVELIZER
MULTI AV
HVAC
Work SupportThis mode enables a technician to adjust some devices
faster and more accurately.xx- -xx-x-x-x
Self-Diagnostic Results Retrieve DTC from ECU and display diagnostic items. x x x x x x x x x x x x
Data MonitorMonitor the input/output signal of the control unit in real
time.xx - xxxxxxxxx
CAN DiagnosisThis mode displays a network diagnosis result about
CAN by a diagram.xx - xxxxxx - xx
CAN Diagnosis Support
MonitorIt monitors the status of CAN communication. x x - x x x x x x - x -
Active TestSend the drive signal from CONSULT-III to the actua-
tor. The operation check can be performed.x - - - xxxxxx - x
DTC & SRT confirma-
tionThe status of system monitoring tests and the self-diag-
nosis status/result can be confirmed.x-----------
ECU IdentificationDisplay the ECU identification number (part number
etc.) of the selected system.xx - - xxxxxxxx
Function TestThis mode can show results of self-diagnosis of ECU
with either "OK" or "NG". For engine, more practical
tests regarding sensors/switches and/or actuators are
available.xxx---xx----
Configuration Function to READ/WRITE vehicle configuration - - - - x - - - - x - -
Special FunctionOther results or histories, etc. that are recorded in ECU
are displayed.-xxx--------

GI-44
< BASIC INSPECTION >
CONSULT-III/GST CHECKING SYSTEM
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-III access to other sys-
tems.
If the GST cannot operate properly, check the circuit based on the information of SAE J1962 and ISO 15031-
3.
Symptom Check item
CONSULT-III/GST cannot ac-
cess any system. CONSULT-III/GST DLC power supply circuit (Terminal 8 and 16) and ground circuit (Terminal 4 and
5)
CONSULT-III cannot access in-
dividual system. (Other sys-
tems can be accessed.) Power supply and ground circuit for the control unit of the system (For detailed circuit, refer to wiring
diagram for each system.)
 Open or short circuit between the system and CONSULT-III DLC (For detailed circuit, refer to wiring
diagram for each system.)
 Open or short circuit CAN communication line. Refer to LAN-14, "
Trouble Diagnosis Flow Chart".

CONSULT-III/GST CHECKING SYSTEM
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Wiring Diagram - CONSULT-III/GST CHECKING SYSTEM -INFOID:0000000003852800
JCAWM0069GB

GI-46
< BASIC INSPECTION >
CONSULT-III/GST CHECKING SYSTEM
JCAWM0070GB

CONSULT-III/GST CHECKING SYSTEM
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JCAWM0071GB