2003 NISSAN X-TRAIL change time

EC-324
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DTC P1144 HO2S1

DTC P1144 HO2S1PFP:22690
Component DescriptionEBS010SB
The heated oxygen sensor 1 is placed into the exhaust manifold. It
detects the amount of oxygen in the exhaust gas compared to the
outside air. The heated oxygen sensor 1 has a closed-end tube
made of ceramic zirconia. The zirconia generates voltage from
approximately 1V in richer conditions to 0V in leaner conditions. The
heated oxygen sensor 1 signal is sent to the ECM. The ECM adjusts
the injection pulse duration to achieve the ideal air-fuel ratio. The
ideal air-fuel ratio occurs near the radical change from 1V to 0V.
CONSULT-II Reference Value in Data Monitor ModeEBS010SC
Specification data are reference values.
On Board Diagnosis LogicEBS010SD
To judge the malfunction, the output from the heated oxygen sensor
1 is monitored to determine whether the “rich” output is sufficiently
high and “lean” output is sufficiently low. When both the outputs are
shifting to the rich side, the malfunction will be detected.
SEF463R
SEF288D
MONITOR ITEM CONDITION SPECIFICATION
HO2S1 (B1)

Engine: After warming upMaintaining engine speed at 2,000
rpm0 - 0.3V ←→ Approx. 0.6 - 1.0V
HO2S1 MNTR (B1)LEAN ←→ RICH
Changes more than 5 times dur-
ing 10 seconds.
SEF299U
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1144
1144Heated oxygen sensor 1
rich shift monitoringThe maximum and minimum voltages from the
sensor are beyond the specified voltages.

Heated oxygen sensor 1

Heated oxygen sensor 1 heater

Fuel pressure

Fuel injector

DTC P1144 HO2S1
EC-329
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6. Check the following.

“HO2S1 MNTR (B1)” in “DATA MONITOR” mode changes
from “RICH” to “LEAN” to “RICH” more than 5 times in 10 sec-
onds.
5 times (cycles) are counted as shown at right.

“HO2S1 (B1)” voltage goes above 0.6V at least once.

“HO2S1 (B1)” voltage goes below 0.3V at least once.

“HO2S1 (B1)” voltage never exceeds 1.0V.
CAUTION:

Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.

Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Set voltmeter probes between ECM terminal 35 (HO2S1 signal) and ground.
3. Check the following with engine speed held at 2,000 rpm con-
stant under no load.

The voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V
more than 5 times within 10 seconds.

The maximum voltage is over 0.6V at least 1 time.

The minimum voltage is below 0.3V at least 1 time.

The voltage never exceeds 1.0V.
1 time: 0 - 0.3V → 0.6 - 1.0V → 0 - 0.3V
2 times: 0 - 0.3V → 0.6 - 1.0V → 0 - 0.3V → 0.6 - 1.0V
→ 0 - 0.3V
CAUTION:

Discard any heated oxygen sensor which has been dropped from a height of more than 0.5 m (19.7
in) onto a hard surface such as a concrete floor; use a new one.

Before installing new oxygen sensor, clean exhaust system threads using Oxygen Sensor Thread
Cleaner tool J-43897-18 or J-43897-12 and approved anti-seize lubricant.
Removal and InstallationEBS010SI
HEATED OXYGEN SENSOR 1
Refer to EM-23, "EXHAUST MANIFOLD AND THREE WAY CATALYST" .
SEF217YA
SEF648Y
MBIB0018E

DTC P1146 HO2S2
EC-331
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DTC Confirmation ProcedureEBS010SM
CAUTION:
Always drive vehicle at a safe speed.
NOTE:

“COMPLETED” will appear on CONSULT-II screen when all tests “COND1”, “COND2” and
“COND3” are completed.

If DTC confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
TESTING CONDITION:
Never stop engine during this procedure. If the engine is stopped, retry procedure from step 2 in Pro-
cedure for COND1
WITH CONSULT-II
Procedure for COND1
For the Best results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30°C(32 to 86°F).
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle 1 minute.
5. Select “HO2S2 (B1) P1146” of “HO2S2” in “DTC WORK SUPPORT” mode with CONSULT-II.
6. Touch “START”.
7. Start engine and let it idle for at least 30 seconds.
8. Rev engine up to 2,000 rpm 2 or 3 times quickly under no load.
If “COMPLETED” appears on CONSULT-II screen, go to step 2 in Procedure for COND3”.
If “COMPLETED” does not appear on CONSULT-II screen, go to the following step.
9. When the following conditions are met, “TESTING” will be displayed at “COND1” on the CONSULT-II
screen. Maintain the conditions continuously until “TESTING” changes to “COMPLETED”. (It will take
approximately 60 seconds.)
NOTE:

If “TESTING” is not displayed after 5 minutes, retry from step 2 in Procedure for COND1.

If “COMPLETED” already appears at “COND2” on CONSULT-II screen before Procedure for
COND2 is conducted, it is unnecessary to conduct step 1 in Procedure for COND2.
ENG SPEED More than 1,000 rpm
B/FUEL SCHDL More than 1.0 msec
COOLAN TEMP/S 70 - 105°C
Selector lever Suitable position
PBIB0555E

DTC P1147 HO2S2
EC-339
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DTC Confirmation ProcedureEBS010SV
CAUTION:
Always drive vehicle at a safe speed.
NOTE:

“COMPLETED” will appear on CONSULT-II screen when all tests “COND1”, “COND2” and
“COND3” are completed.

If DTC confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait
at least 10 seconds before conducting the next test.
TESTING CONDITION:
Never stop engine during this procedure. If the engine is stopped, retry procedure from step 2 in “Pro-
cedure for COND1”
WITH CONSULT-II
Procedure for COND1
For the best results, perform “DTC WORK SUPPORT” at a temperature of 0 to 30°C(32 to 86°F).
1. Start engine and warm it up to normal operating temperature.
2. Turn ignition switch OFF and wait at least 10 seconds.
3. Start engine and keep the engine speed between 3,500 and 4,000 rpm for at least 1 minute under no load.
4. Let engine idle 1 minute.
5. Select “HO2S2 (B1) P1147” of “HO2S2” in “DTC WORK SUPPORT” mode with CONSULT-II.
6. Touch “START”.
7. Start engine and let it idle for at least 30 seconds.
8. Rev engine up to 2,000 rpm 2 or 3 times quickly under no load.
If “COMPLETED” appears on CONSULT-II screen, go to step 2 in “Procedure for COND3”.
If “COMPLETED” does not appear on CONSULT-II screen, go to the following step.
9. When the following conditions are met, “TESTING” will be displayed at COND1” on the CONSULT-II
screen. Maintain the conditions continuously until “TESTING” changes to “COMPLETED”. (It will take
approximately 60 seconds.)
NOTE:

If “TESTING” is not displayed after 5 minutes, retry from step 2 in Procedure for COND1.

If “COMPLETED” already appears at “COND2” on CONSULT-II screen before Procedure for
COND2 is conducted, it is unnecessary to conduct step 1 in Procedure for COND2.
ENG SPEED More than 1,000 rpm
B/FUEL SCHDL More than 1.0 msec
COOLAN TEMP/S 70 - 105°C
Selector lever Suitable position
PBIB0557E

ENGINE CONTROL SYSTEM
EC-497
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*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from both the crankshaft position sensor and the mass air
flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.


During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D (A/T models)

High-load, high-speed operation


During deceleration

During high engine speed operation
MIXTURE RATIO FEEDBACK CONTROL (CLOSED LOOP CONTROL)
The mixture ratio feedback system provides the best air-fuel mixture ratio for driveability and emission control.
The three way catalyst (manifold) can then better reduce CO, HC and NOx emissions. This system uses
heated oxygen sensor 1 in the exhaust manifold to monitor whether the engine operation is rich or lean. The
ECM adjusts the injection pulse width according to the sensor voltage signal. For more information about
heated oxygen sensor 1, refer to EC-176
. This maintains the mixture ratio within the range of stoichiometric
(ideal air-fuel mixture).
This stage is referred to as the closed loop control condition.
Heated oxygen sensor 2 is located downstream of the three way catalyst (manifold). Even if the switching
characteristics of heated oxygen sensor 1 shift, the air-fuel ratio is controlled to stoichiometric by the signal
from heated oxygen sensor 2.
Open Loop Control
The open loop system condition refers to when the ECM detects any of the following conditions. Feedback
control stops in order to maintain stabilized fuel combustion.

Deceleration and acceleration

High-load, high-speed operation

Malfunction of heated oxygen sensor 1 or its circuit

Insufficient activation of heated oxygen sensor 1 at low engine coolant temperature

High engine coolant temperature

During warm-up

After shifting from N to D (A/T models)

When starting the engine
PBIB0121E

EC-498
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ENGINE CONTROL SYSTEM

MIXTURE RATIO SELF-LEARNING CONTROL
The mixture ratio feedback control system monitors the mixture ratio signal transmitted from heated oxygen
sensor 1. This feedback signal is then sent to the ECM. The ECM controls the basic mixture ratio as close to
the theoretical mixture ratio as possible. However, the basic mixture ratio is not necessarily controlled as orig-
inally designed. Both manufacturing differences (i.e., mass air flow sensor hot wire) and characteristic
changes during operation (i.e., injector clogging) directly affect mixture ratio.
Accordingly, the difference between the basic and theoretical mixture ratios is monitored in this system. This is
then computed in terms of “injection pulse duration” to automatically compensate for the difference between
the two ratios.
“Fuel trim” refers to the feedback compensation value compared against the basic injection duration. Fuel trim
includes short term fuel trim and long term fuel trim.
“Short term fuel trim” is the short-term fuel compensation used to maintain the mixture ratio at its theoretical
value. The signal from heated oxygen sensor 1 indicates whether the mixture ratio is RICH or LEAN compared
to the theoretical value. The signal then triggers a reduction in fuel volume if the mixture ratio is rich, and an
increase in fuel volume if it is lean.
“Long term fuel trim” is overall fuel compensation carried out long-term to compensate for continual deviation
of the short term fuel trim from the central value. Such deviation will occur due to individual engine differences,
wear over time and changes in the usage environment.
FUEL INJECTION TIMING
Two types of systems are used.
Sequential Multiport Fuel Injection System
Fuel is injected into each cylinder during each engine cycle according to the firing order. This system is used
when the engine is running.
Simultaneous Multiport Fuel Injection System
Fuel is injected simultaneously into all four cylinders twice each engine cycle. In other words, pulse signals of
the same width are simultaneously transmitted from the ECM.
The four injectors will then receive the signals two times for each engine cycle.
This system is used when the engine is being started and/or if the fail-safe system (CPU) is operating.
FUEL SHUT-OFF
Fuel to each cylinder is cut off during deceleration or operation of the engine at excessively high speeds.
SEF337W

EC-518
[QR (WITHOUT EURO-OBD)]
ON BOARD DIAGNOSTIC (OBD) SYSTEM

DIAGNOSTIC TEST MODE I — MALFUNCTION WARNING

These DTC numbers are clarified in Diagnostic Test Mode II (SELF-DIAGNOSTIC RESULTS)
DIAGNOSTIC TEST MODE II — SELF-DIAGNOSTIC RESULTS
In this mode, the DTC and 1st trip DTC are indicated by the number of blinks of the MI as shown below.
The DTC and 1st trip DTC are displayed at the same time. If the MI does not illuminate in diagnostic test mode
I (Malfunction warning), all displayed items are 1st trip DTCs. If only one code is displayed when the MI illumi-
nates in diagnostic test mode II (SELF-DIAGNOSTIC RESULTS), it is a DTC; if two or more codes are dis-
played, they may be either DTCs or 1st trip DTCs. DTC No. is same as that of 1st trip DTC. These unidentified
codes can be identified by using the CONSULT-II. A DTC will be used as an example for how to read a code.
A particular trouble code can be identified by the number of four-digit numeral flashes. The “zero” is indicated
by the number of ten flashes. The length of time the 1,000th-digit numeral flashes on and off is 1.2 seconds
consisting of an ON (0.6-second) - OFF (0.6-second) cycle.
The 100th-digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second OFF cycle.
A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other words, the later
numeral appears on the display 1.3 seconds after the former numeral has disappeared.
A change from one trouble code to another occurs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-482, "
INDEX FOR DTC" )
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal. Refer to EC-
517, "HOW TO SWITCH DIAGNOSTIC TEST MODE" .

If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.

Be careful not to erase the stored memory before starting trouble diagnoses.
DIAGNOSTIC TEST MODE II — HEATED OXYGEN SENSOR 1 MONITOR
In this mode, the MI displays the condition of the fuel mixture (lean or rich) which is monitored by the heated
oxygen sensor 1.
*: Maintains conditions just before switching to open loop.MI Condition
ON When the malfunction is detected.
OFF No malfunction.
PBIA3905E
MI Fuel mixture condition in the exhaust gas Air fuel ratio feedback control condition
ON Lean
Closed loop system
OFF Rich
*Remains ON or OFF Any condition Open loop system

EC-558
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TROUBLE DIAGNOSIS

NOTE:
Any monitored item that does not match the vehicle being diagnosed is deleted from the display automatically.
ACTIVE TEST MODE
Test Item
*:Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION

Engine: Return to the original
trouble condition

Change the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Fuel injector

Heated oxygen sensor 1
IGNITION TIM-
ING

Engine: Return to the original
trouble condition

Timing light: Set

Retard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Perform Idle Air Volume Learning.
POWER BAL-
ANCE

Engine: After warming up, idle
the engine.

Air conditioner switch OFF

Shift lever: N (A/T), Neutral (M/T)

Cut off each injector signal one at
a time using CONSULT-II.Engine runs rough or dies.

Harness and connectors

Compression

Fuel injector

Power transistor

Spark plug

Ignition coil
COOLING FAN*

Ignition switch: ON

Turn the cooling fan LOW, HI,
OFF with CONSULT-II.Cooling fan moves and stops.

Harness and connectors

Cooling fan relay

Cooling fan motor
ENG COOLANT
TEMP

Engine: Return to the original
trouble condition

Change the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Engine coolant temperature sen-
sor

Fuel injector
FUEL PUMP
RELAY

Ignition switch: ON (Engine
stopped)

Turn the fuel pump relay ON and
OFF using CONSULT-II and lis-
ten to operating sound.Fuel pump relay makes the operat-
ing sound.
Harness and connectors

Fuel pump relay
PURG VOL
CONT/V

Engine: After warming up, run
engine at 1,500 rpm.

Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II.Engine speed changes according to
the opening percent.
Harness and connectors

Solenoid valve
V/T ASSIGN
ANGLE

Engine: Return to the original
trouble condition

Change intake valve timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.

Harness and connectors

Intake valve timing control sole-
noid valve