2003 NISSAN ALMERA N16 OBD port

ENGINE CONTROL SYSTEM
EC-27
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Fuel Cut Control (at No Load and High Engine Speed)EBS00K38
INPUT/OUTPUT SIGNAL CHART
*1: This signal is sent to the ECM through CAN communication line.
SYSTEM DESCRIPTION
If the engine speed is above 3,950 rpm with no load (for example, in neutral and engine speed over 3,950
rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed.
Fuel cut will operate until the engine speed reaches 1,500 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under “Multiport Fuel Injection (MFI) System”, EC-23
.
CAN CommunicationEBS00K39
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
CAN COMMUNICATION UNIT
×:ApplicableSensor Input Signal to ECM ECM Function Actuator
Park/neutral position (PNP) switch Neutral position
Fuel cut control Fuel injectors Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed
Vehicle speed signal
*1Vehicle speed
Body type Sedan/ 5DH/B/ 3DH/B
Axle2WD
Engine QG18DE QG15DE/QG18DE
Transmission A/T M/T
Brake controlABS
CAN communication unit
ECM××
TCM×
Smart entrance control unit××
Data link connector××
Combination meter××
CAN communication type EC-28, "
Type 1"EC-29, "Ty p e 2"

EC-32
[QG (WITH EURO-OBD)]
BASIC SERVICE PROCEDURE
PREPARATION
Before performing “Idle Air Volume Learning”, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
●Battery voltage: More than 12.9V (At idle)
●Engine coolant temperature: 70 - 95°C (158 - 203°F)
●PNP switch: ON
●Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, set lighting switch to the 1st position to light
only small lamps.
●Steering wheel: Neutral (Straight-ahead position)
●Vehicle speed: Stopped
●Transmission: Warmed-up
For A/T models with CONSULT-II, drive vehicle until “FLUID TEMP SE” in “DATA MONITOR” mode of “A/
T” system indicates less than 0.9V.
For A/T models without CONSULT-II and M/T models, drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-II
1. Perform EC-31, "Accelerator Pedal Released Position Learning" .
2. Perform EC-31, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic “PREPARATION” (previously mentioned) are in good order.
5. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
6. Touch “START” and wait 20 seconds.
SEF217Z
SEF454Y

EC-34
[QG (WITH EURO-OBD)]
BASIC SERVICE PROCEDURE
DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:
1.Check that throttle valve is fully closed.
2.Check PCV valve operation.
3.Check that downstream of throttle valve is free from air leakage.
4.When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and eliminate the cause of the incident.
It is useful to perform EC-105, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
5.If any of the following conditions occur after the engine has started, eliminate the cause of the
incident and perform “Idle air volume learning” all over again:
–Engine stalls.
–Erroneous idle.
Fuel Pressure CheckEBS00K3E
FUEL PRESSURE RELEASE
Before disconnecting fuel line, release fuel pressure from fuel line to eliminate danger.
NOTE:
Prepare pans or saucers under the disconnected fuel line because the fuel may spill out. The fuel pres-
sure cannot be completely released because N16 models do not have fuel return system.
With CONSULT-II
1. Turn ignition switch “ON”.
2. Perform “FUEL PRESSURE RELEASE” in “WORK SUPPORT”
mode with CONSULT-II.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel
pressure.
5. Turn ignition switch “OFF”.
Without CONSULT-II
1. Remove fuel pump fuse located in fuse box.
2. Start engine.
3. After engine stalls, crank it two or three times to release all fuel
pressure.
4. Turn ignition switch “OFF”.
5. Reinstall fuel pump fuse after servicing fuel system.
FUEL PRESSURE CHECK
NOTE:
●When reconnecting fuel line, always use new clamps.
●Make sure that clamp screw does not contact adjacent parts.
●Use a torque driver to tighten clamps.
●Use Pressure Gauge to check fuel pressure.
1. Release fuel pressure to zero. Refer to EC-34, "
FUEL PRESSURE RELEASE" .
SEF214Y
MBIB0262E

EC-40
[QG (WITH EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
If a 1st trip DTC is stored in the ECM, the time data will be “[1t]”.
FREEZE FRAME DATA AND 1ST TRIP FREEZE FRAME DATA
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short term fuel trim, long term fuel trim, engine speed, vehicle speed, base fuel schedule and intake
air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II or
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
details, see EC-90, "
Freeze Frame Data and 1st Trip Freeze Frame Data" .
Only one set of freeze frame data (either 1st trip freeze frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MI on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
For example, the EGR malfunction (Priority: 2) was detected and the freeze frame data was stored in the 2nd
trip. After that when the misfire (Priority: 1) is detected in another trip, the freeze frame data will be updated
from the EGR malfunction to the misfire. The 1st trip freeze frame data is updated each time a different mal-
function is detected. There is no priority for 1st trip freeze frame data. However, once freeze frame data is
stored in the ECM memory, 1st trip freeze data is no longer stored (because only one freeze frame data or 1st
trip freeze frame data can be stored in the ECM). If freeze frame data is stored in the ECM memory and freeze
frame data with the same priority occurs later, the first (original) freeze frame data remains unchanged in the
ECM memory.
Both 1st trip freeze frame data and freeze frame data (along with the DTCs) are cleared when the ECM mem-
ory is erased. Procedures for clearing the ECM memory are described in EC-48, "
HOW TO ERASE EMIS-
SION-RELATED DIAGNOSTIC INFORMATION" .
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Mode 1 of ISO 15031-5.
As part of an enhanced emissions test for Inspection & Maintenance (I/M), certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major emission systems and com-
ponents. Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspection due to one or more SRT items indicating “INCMP”, use
the information in this Service Manual to set the SRT to “CMPLT”.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate “CMPLT” for each application system. Once set as “CMPLT”, the SRT status remains
“CMPLT” until the self-diagnosis memory is erased.
Occasionally, certain portions of the self-diagnostic test may not be completed as a result of the customer's
normal driving pattern; the SRT will indicate “INCMP” for these items.
NOTE:
The SRT will also indicate “INCMP” if the self-diagnosis memory is erased for any reason or if the ECM mem-
ory power supply is interrupted for several hours.
PBIB0911E
Priority Items
1Freeze frame data Misfire — DTC: P0300 - P0304
Fuel Injection System Function — DTC: P0171, P0172
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-41
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If, during the state emissions inspection, the SRT indicates “CMPLT” for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT indicates “INCMP” for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
If MI is “ON” during the state emissions inspection, the vehicle is also returned to the customer untested even
though the SRT indicates “CMPLT” for all test items. Therefore, it is important to check SRT (“CMPLT”) and
DTC (No DTCs) before the inspection.

EC-58
[QG (WITH EURO-OBD)]
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSIS
PFP:00004
Trouble Diagnosis IntroductionEBS00K3L
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose a incident that occurs intermit-
tently 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 replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II (or GST) or a circuit tester connected should
be performed. Follow the “Work Flow” on EC-59
.
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 exam-
ple on EC-62
should be used.
Start your diagnosis by looking for “conventional” malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
MEF036D
SEF233G
SEF234G

TROUBLE DIAGNOSIS
EC-61
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DIAGNOSTIC WORKSHEET
Description
There are many operating conditions that lead to the malfunction of
engine components. A good grasp of such conditions can make trou-
bleshooting faster and more accurate.
In general, each customer feels differently about a incident. It is
important to fully understand the symptoms or conditions for a cus-
tomer complaint.
Utilize a diagnostic worksheet like the one on the next page in order
to organize all the information for troubleshooting.
Some conditions may cause the MI to come on steady or blink and
DTC to be detected. Examples:
●Vehicle ran out of fuel, which caused the engine to misfire.
●Fuel filler cap was left off or incorrectly screwed on, allowing fuel
to evaporate into the atmosphere.
SEF907L

TROUBLE DIAGNOSIS
EC-87
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: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
CONSULT-II FunctionEBS00K3U
FUNCTION
*1: The following emission-related diagnostic information is cleared when the ECM memory is erased.
●Diagnostic trouble codes
●1st trip diagnostic trouble codes
●Freeze frame data
●1st trip freeze frame data
●System readiness test (SRT) codes
●Test values
●Others109 B/R Ignition switch[Ignition switch “OFF”]0V
[Ignition switch “ON”]BATTERY VOLTAGE
(11 - 14V)
111 W/G ECM relay (Self shut-off)[Engine is running]
[Ignition switch “OFF”]
●For 5 seconds after turning ignition switch
“OFF”.0 - 1.0V
[Ignition switch “OFF”]
●5 seconds passed after turning ignition
switch “OFF”.BATTERY VOLTAGE
(11 - 14V)
113 B/P Fuel pump relay[Ignition switch “ON”]
●For 1 second after turning ignition switch
“ON”.
[Engine is running]0 - 1.0V
[Ignition switch “ON”]
●More than 1 second after turning ignition
switch “ON”.BATTERY VOLTAGE
(11 - 14V)
11 5
11 6B
BECM ground[Engine is running]
●Idle speedEngine ground
11 9
120W
WPower supply for ECM[Ignition switch “ON”]BATTERY VOLTAGE
(11 - 14V)
121 W/LPower supply for ECM
(Buck-up)[Ignition switch “OFF”]BATTERY VOLTAGE
(11 - 14V) TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
Diagnostic test mode Function
Work supportThis mode enables a technician to adjust some devices faster and more accurately by following the
indications on the CONSULT-II unit.
Self-diagnostic resultsSelf-diagnostic results such as 1st trip DTC, DTCs and 1st trip freeze frame data or freeze frame data
can be read and erased quickly.
*1
Data monitor Input/Output data in the ECM can be read.
Data monitor (SPEC)Input/Output of the specification for Basic fuel schedule, AFM, A/F feedback control value and the
other data monitor items can be read.
Active testDiagnostic Test Mode in which CONSULT-II drives some actuators apart from the ECMs and also
shifts some parameters in a specified range.
Function test This mode is used to inform customers when their vehicle condition requires periodic maintenance.
DTC & SRT confirmation The status of system monitoring tests and the self-diagnosis status/result can be confirmed.
ECM part number ECM part number can be read.