
no voltage; short is further down the circuit than the relay.
5) 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 INSPECTIONNJGI0005S0304Ground 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 corro-
sion (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 eas-
ily 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:
1) Remove the ground bolt or screw.
2) Inspect all mating surfaces for tarnish, dirt, rust, etc.
3) Clean as required to assure good contact.
4) Reinstall bolt or screw securely.
5) Inspect for “add-on” accessories which may be interfering with
the ground circuit.
6) 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.
SGI853
VOLTAGE DROP TESTSNJGI0005S0305Voltage drop tests are often used to find components or circuits
which have excessive resistance. A voltage drop in a circuit is
caused by a resistancewhen the circuit is in operation.
Check the wire in the illustration. When measuring resistance with
ohmmeter, 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
HOW TO PERFORM EFFICIENT DIAGNOSES FOR AN ELECTRICAL INCIDENT
Circuit Inspection (Cont’d)
GI-28

SEF858S
Introduction
SEF233G
SEF234G
NJEC0630The engine has an ECM to control major systems such as fuel
injection control, fuel injection timing control, glow control system,
etc. The ECM accepts input signals from sensors and instantly
drives electronic control fuel injection pump. It is essential that both
input and output signals are proper and stable. At the same time,
it is important that there are no malfunctions such as vacuum leaks,
or other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs inter-
mittently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this
case, careful checking of suspected circuits may help prevent the
replacement of good parts.
A visual check only may not find the cause of the malfunctions. A
road test with CONSULT-II or a circuit tester connected should be
performed. Follow the “Work Flow”, EC-46.
Before undertaking actual checks, take a few minutes to talk with
a customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the
example on next page should be used.
Start your diagnosis by looking for “conventional” malfunctions first.
This will help troubleshoot driveability incidents on an electronically
controlled engine vehicle.
SEF907L
DIAGNOSTIC WORKSHEETNJEC0630S01There are many operating conditions that lead to the malfunction
of engine components. A good grasp of such conditions can make
troubleshooting faster and more accurate.
In general, each customer feels differently about an incident. It is
important to fully understand the symptoms or conditions for a
customer complaint.
Utilize a diagnostic worksheet like the one shown below in order to
organize all the information for troubleshooting.
TROUBLE DIAGNOSIS — INTRODUCTIONYD
Introduction
EC-44

AT-28
OVERALL SYSTEM
TCM FUNCTION
The function of the TCM is to:
●Receive input signals sent from various switches and sensors.
●Determine required line pressure, shifting point, lock-up operation, and engine brake operation.
●Send required output signals to the respective solenoid valves.
INPUT/OUTPUT SIGNAL OF TCM
Control MechanismECS007NK
LINE PRESSURE CONTROL
TCM has various line pressure control characteristics to match the driving conditions.
An ON-OFF duty signal is sent to the line pressure solenoid valve based on TCM characteristics.
Hydraulic pressure on the clutch and brake is electronically controlled through the line pressure solenoid valve
to accommodate engine torque. This results in smooth shift operation.
Normal Control
The line pressure to throttle opening characteristics is set for suitable
clutch operation.
Sensors, switches and solenoid
valvesFunction
InputPNP switch Detects select lever position and sends a signal to TCM.
Throttle position sensor (accelerator
pedal position (APP) sensor)Detects throttle valve position and sends a signal to TCM.
Engine speed signal From ECM.
A/T fluid temperature sensor Detects transmission fluid temperature and sends a signal to TCM.
Revolution sensor Detects output shaft rpm and sends a signal to TCM.
Vehicle speed sensorUsed as an auxiliary vehicle speed sensor. Sends a signal when revolution
sensor (installed on transmission) malfunctions.
Overdrive control switchSends a signal, which prohibits a shift to “D
4 ” (overdrive) position, to the
TCM.
Stop lamp switch Releases lock-up system when depressing pedal in lock-up condition.
OutputShift solenoid valve A/BSelects shifting point suited to driving conditions in relation to a signal sent
from TCM.
Line pressure solenoid valveRegulates (or decreases) line pressure suited to driving conditions in relation
to a signal sent from TCM.
Torque converter clutch solenoid
valveRegulates (or decreases) lock-up pressure suited to driving conditions in rela-
tion to a signal sent from TCM.
Overrun clutch solenoid valveControls an “engine brake” effect suited to driving conditions in relation to a
signal sent from TCM.
O/D OFF indicator lamp Shows TCM faults when A/T control components malfunction.
SAT003J
![NISSAN ALMERA N16 2003 Electronic Repair Manual AT-56
[EURO-OBD]
TROUBLE DIAGNOSIS — INTRODUCTION
TROUBLE DIAGNOSIS — INTRODUCTION
PFP:00000
IntroductionECS007NU
The TCM receives a signal from the vehicle speed sensor, throttle
position sensor NISSAN ALMERA N16 2003 Electronic Repair Manual AT-56
[EURO-OBD]
TROUBLE DIAGNOSIS — INTRODUCTION
TROUBLE DIAGNOSIS — INTRODUCTION
PFP:00000
IntroductionECS007NU
The TCM receives a signal from the vehicle speed sensor, throttle
position sensor](/manual-img/5/57350/w960_57350-1511.png)
AT-56
[EURO-OBD]
TROUBLE DIAGNOSIS — INTRODUCTION
TROUBLE DIAGNOSIS — INTRODUCTION
PFP:00000
IntroductionECS007NU
The TCM receives a signal from the vehicle speed sensor, throttle
position sensor or PNP switch and provides shift control or lock-up
control via A/T solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used with the EURO-OBD related parts
of the A/T system for malfunction-diagnostic purposes. The TCM is
capable of diagnosing malfunctioning parts while the ECM can store
malfunctions in its memory.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only, may not find the cause of the problems. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the “Work Flow”. Refer to AT- 6 0 , "
Work Flow" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a drive ability complaint. The cus-
tomer can supply good information about such problems, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple (AT- 5 7 , "
DIAGNOSTIC WORKSHEET" ) should be used.
Start your diagnosis by looking for “conventional” problems first. This
will help troubleshoot drive ability problems on an electronically con-
trolled engine vehicle.
Also check related Service bulletins for information.
SAT631IA
SAT632I
SEF234G
![NISSAN ALMERA N16 2003 Electronic Repair Manual TROUBLE DIAGNOSIS — INTRODUCTION
AT-255
[EXC.F/EURO-OBD]
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AT-255
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TROUBLE DIAGNOSIS — INTRODUCTION
AT-255
[EXC.F/EURO-OBD]
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TROUBLE DIAGNOSIS — INTRODUCTIONPFP:00000
IntroductionECS007QP
The TCM receives a signal from the vehicle speed sensor, throttle
position sensor or PNP switch and provides shift control or lock-up
control via A/T solenoid valves.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a problem that occurs intermit-
tently rather than continuously. Most intermittent problems are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only, may not find the cause of the problems. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow the “Work Flow”. Refer to AT- 2 5 9 , "
Work Flow" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a drive ability complaint. The cus-
tomer can supply good information about such problems, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “Diagnostic Worksheet” like the exam-
ple (AT-256, "
DIAGNOSTIC WORKSHEET" ) should be used.
Start your diagnosis by looking for “conventional” problems first. This
will help troubleshoot drive ability problems on an electronically con-
trolled engine vehicle.
Also check related Service bulletins for information.
SAT631IA
SAT632I
SEF234G

PRECAUTIONS
ATC-9
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AT C
SERVICE COUPLERS
Never attempt to connect HFC-134a (R-134a) service couplers to an
CFC-12 (R-12) A/C system. The HFC-134a (R-134a) couplers will
not properly connect to the CFC-12 (R-12) system. However, if an
improper connection is attempted, discharging and contamination
may occur.
REFRIGERANT WEIGHT SCALE
Verify that no refrigerant other than HFC-134a (R-134a) and speci-
fied lubricants have been used with the scale. If the scale controls
refrigerant flow electronically, the hose fitting must be 1/2″-16
ACME.
CALIBRATING ACR4 WEIGHT SCALE
Calibrate the scale every three months.
To calibrate the weight scale on the ACR4:
1. Press Shift/Reset and Enter at the same time.
2. Press 8787 . “A1 ” will be displayed.
3. Remove all weight from the scale.
4. Press 0 , then press Enter . “0.00 ” will be displayed and change to “A2 ”.
5. Place a known weight (dumbbell or similar weight), between 4.5 and 8.6 kg (10 and 19 lb) on the center of
the weight scale.
6. Enter the known weight using four digits. (Example 10 lb = 10.00, 10.5 lb = 10.50)
7. Press Enter — the display returns to the vacuum mode.
8. Press Shift/Reset and Enter at the same time.
9. Press 6 — the known weight on the scale is displayed.
10. Remove the known weight from the scale. “0.00 ” will be displayed.
11 . P r e s s Shift/Reset to return the ACR4 to the program mode.
CHARGING CYLINDER
Using a charging cylinder is not recommended. Refrigerant may be vented into air from cylinder′s top valve
when filling the cylinder with refrigerant. Also, the accuracy of the cylinder is generally less than that of an
electronic scale or of quality recycle/recharge equipment.
Precautions for Leak Detection DyeEJS001YW
●The A/C system contains a fluorescent leak detection dye used for locating refrigerant leaks. An ultraviolet
(UV) lamp is required to illuminate the dye when inspecting for leaks.
●Always wear fluorescence enhancing UV safety glasses to protect your eyes and enhance the visibility of
the fluorescent dye.
●The fluorescent dye leak detector is not a replacement for an electronic refrigerant leak detector. The fluo-
rescent dye leak detector should be used in conjunction with an electronic refrigerant leak detector to (J-
41995) pin-point refrigerant leaks.
●For your safety and your Customer′s satisfaction, read and follow all manufacture′s operating instructions
and precautions prior to performing the work.
Shut-off valve rotation A/C service valve
Clockwise Open
Counterclockwise Close
RHA273D
RHA274D

RHA273D
SERVICE COUPLERSNJHA0117S06Never attempt to connect HFC-134a (R-134a) service couplers to
an CFC-12 (R-12) A/C system. The HFC-134a (R-134a) couplers
will not properly connect to the CFC-12 (R-12) system. However, if
an improper connection is attempted, discharging and contamina-
tion may occur.
Shut-off valve rotation A/C service valve
Clockwise Open
Counterclockwise Close
RHA274D
REFRIGERANT WEIGHT SCALENJHA0117S07Verify that no refrigerant other than HFC-134a (R-134a) and speci-
fied lubricants have been used with the scale. If the scale controls
refrigerant flow electronically, the hose fitting must be 1/2″-16
ACME.
CALIBRATING ACR4 WEIGHT SCALENJHA0117S09Calibrate the scale every three months.
To calibrate the weight scale on the ACR4:
1. PressShift/ResetandEnterat the same time.
2. Press8787.“A1” will be displayed.
3. Remove all weight from the scale.
4. Press0, then pressEnter.“0.00” will be displayed and change
to “A2”.
5. Place a known weight (dumbbell or similar weight), between
4.5 and 36.3 kg (10 and 80 lb) on the center of the weight
scale.
6. Enter the known weight using four digits. (Example 10 lb =
“10.00”, 10.5 lb = “10.50”)
7. PressEnter— the display returns to the vacuum mode.
8. PressShift/ResetandEnterat the same time.
9. Press6— the known weight on the scale is displayed.
10. Remove the known weight from the scale. “0.00” will be dis-
played.
11. PressShift/Resetto return the ACR4 to the program mode.
CHARGING CYLINDERNJHA0117S08Using a charging cylinder is not recommended. Refrigerant may be
vented into air from cylinder’s top valve when filling the cylinder
with refrigerant. Also, the accuracy of the cylinder is generally less
than that of an electronic scale or of quality recycle/recharge
equipment.
GI
MA
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LC
EC
FE
CL
MT
AT
AX
SU
BR
ST
RS
BT
SC
EL
IDX
PRECAUTIONSMANUAL
Precautions for Service Equipment (Cont’d)
HA-7