check engine light NISSAN TEANA 2014 User Guide

SYSTEMEC-41
< SYSTEM DESCRIPTION > [QR25DE]
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ECM controls the engine by various functions.
ENGINE CONTROL SYSTEM : Fail SafeINFOID:0000000009462092
NON DTC RELATED ITEM
DTC RELATED ITEM
Description
When a DTC is detected, ECM executes a mode (in the
Fail-safe mode) applicable to the DTC. The fail-safe
mode has the preset traveling control mode (accelera tor angle variation and engine output limit) and device fix
mode.
Function Reference
Multiport fuel injection system EC-43, "MULTIPORT FUEL INJECTION SYSTEM : System De-
scription (with automatic air conditioner)"
Electric ignition system
EC-48, "ELECTRIC IGNITION SYSTEM : System Description"
Intake valve timing control EC-49, "INTAKE VALVE TIMING CONTROL : System Description"
Exhaust valve timing control EC-52, "EXHAUST VALVE TIMING
CONTROL : System Descrip-tion"
Intake manifold runner control EC-53, "INTAKE MANIFOLD RUNNER CONTROL : System De-scription"
Intake manifold tuning system
EC-54, "INTAKE MANIFOLD TUNI
NG SYSTEM : System Descrip-tion"
Engine protection control EC-55, "ENGINE PROTECTION CONTROL AT LOW ENGINE OIL PRESSURE : System Description"
Fuel filler cap warning systemEC-56, "FUEL FILLER CAP WARNING SYSTEM : System De-scription"
Air conditioning cut control
EC-56, "AIR CONDITIONING CUT CONTROL : System Descrip-tion (with automatic air conditioner)"
Cooling fan controlEC-59, "COOLING FAN CONTROL :
System Description (with au-tomatic air conditioner)"
Evaporative emission system EC-62, "EVAPORATIVE EMISSION
SYSTEM : System Descrip-tion"
Automatic speed control device (ASCD) EC-63, "AUTOMATIC SPEED CONTROL DEVICE (ASCD) : Sys-tem Description"
CAN communication
EC-64, "CAN COMMUNICATION : System Description"
Detected
items Engine operating condition
in fail-safe mode Remarks Reference page
Malfunction
indicator
lamp circuit Engine speed will not rise
more than 2,500 rpm due
to the fuel cut When there is an open circuit on MIL circuit, the ECM cannot warn the
driver by lighting up MIL when there is malfunction on engine control
system.
Therefore, when electrical controlled throttle and part of ECM related
diagnoses are continuously detected as NG for 5 trips, ECM warns the
driver that engine control system malfunctions and MIL circuit is open
by means of operating fail safe function.
The fail safe function also operates when above diagnoses except MIL
circuit are detected and demands the driver to repair the malfunction. EC-517, "Compo-
nent Function
Check"
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DIAGNOSIS SYSTEM (ECM)EC-67
< SYSTEM DESCRIPTION > [QR25DE]
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DIAGNOSIS SYSTEM (ECM)
DIAGNOSIS DESCRIPTION
DIAGNOSIS DESCRIPTION : 1s
t Trip Detection Logic and Two Trip Detection Logic
INFOID:0000000009462112
When a malfunction is detected for the first time, 1st tr ip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MIL will not illuminate at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MIL illuminates. The MIL illu minates at the same time when the DTC is stored.
<2nd trip> The “trip” in the “Two Trip Detection Logic” means a driving mode in which self-diagnosis is per-
formed during vehicle operation. Specific on board diagnosti c items will cause the ECM to illuminate or blink
the MIL, and store DTC and Freeze Frame data, even in the 1st trip, as shown below.
×: Applicable —: Not applicable
DIAGNOSIS DESCRIPTION : DTC and Freeze Frame DataINFOID:0000000009462113
DTC AND 1ST TRIP DTC
The 1st trip DTC (whose number is the same as the DT C number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously , and the 1st trip DTC did not recur, the 1st trip DTC
will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is saved in the ECM memory. The MIL will not
light up (two trip detection logic). If the same malfunc tion is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are saved in t he ECM memory and the MIL lights up. In other words,
the DTC is stored in the ECM memory and the MIL light s up when the same malfunction occurs in two consec-
utive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd
trips, only the 1st trip DTC will continue to be stored. Fo r malfunctions that blink or light up the MIL during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
For malfunctions in which 1st trip DTCs are displayed, refer to EC-105, "DTC Index"
. These items are
required by legal regulations to c ontinuously monitor the system/component . In addition, the items monitored
non-continuously are also displayed on CONSULT.
1st trip DTC is specified in Service $07 of SAE J1979/ ISO 15031-5. 1st trip DTC detection occurs without illu-
minating the MIL and therefore does not warn the driver of a malfunction.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step 2, refer to EC-165, "Work Flow"
. Then perform DTC Confirma-
tion Procedure or Component Function Check to try to duplicate the malfunction. If the malfunction is dupli-
cated, the item requires repair.
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, engi ne speed, vehicle speed, absolute throttle position, 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 or
GST. The 1st trip freeze frame data c an only be displayed on the CONSULT screen.
Items MIL DTC 1st trip DTC
1st trip 2nd trip 1st trip
displaying 2nd trip
displaying 1st trip
displaying 2nd trip
display- ing
Blinking Illuminat-
ed Blinking Illuminat-
ed
Misfire (Possible three way catalyst
damage) — DTC: P0300 – P0304
is being detected ×
———— — ×—
Misfire (Possible three way catalyst
damage) — DTC: P0300 – P0304
is being detected ——
×—— ×——
One trip detection diagnoses (Re-
fer to EC-105, "DTC Index"
.) —
×—— ×———
Except above — — — ×— ×× —
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EC-74
< SYSTEM DESCRIPTION >[QR25DE]
DIAGNOSIS SYSTEM (ECM)
PERMANENT DTC SET TIMING
The setting timing of permanent DTC is stored in EC
M with the lighting of MIL when a DTC is confirmed.
DIAGNOSIS DESCRIPTION : Malfunction Indicator Lamp (MIL)INFOID:0000000009462118
When emission-related ECU detects a malfunction in the emission
control systems components and/or the powertrain control compo-
nents (which affect vehicle emissions), it turns on/blinks MIL to
inform the driver that a malfunction has been detected.
1. The MIL illuminates when ignition switch is turned ON (engine is not running).
NOTE:
Check the MIL circuit if MIL does not illuminate. Refer to EC-
517, "Diagnosis Procedure".
2. When the engine is started, the MIL should go off.
NOTE:
If MIL continues to illuminate/blink, perform self-diagnoses and
inspect/repair accordingly because an emission-rela ted ECU has detected a malfunction in the emission
control systems components and/or the powertrain cont rol components (which affect vehicle emissions).
On Board Diagnosis FunctionINFOID:0000000009462119
ON BOARD DIAGNOSIS ITEM
The on board diagnostic system has the following functions.
BULB CHECK MODE
Description
This function allows damage inspection in the MIL bulb (blown, open circuit, etc.).
Operation Procedure
1. Turn ignition switch ON.
2. The MIL on the instrument panel should stay ON. If it remains OFF, check MIL circuit. Refer to EC-517, "Diagnosis Procedure"
.
SRT STATUS MODE
Description
This function allows to read if ECM has completed t he self-diagnoses of major emission control systems and
components. For SRT, refer to EC-72, "DIAGNOSIS DESCRIPTION : System Readiness Test (SRT) Code"
.
Operation Procedure
1. Turn ignition switch ON and wait 20 seconds.
2. SRT status is indicated as shown blow. • ECM continues to illuminate MIL if all SRT codes are set.
JSBIA1315ZZ
Diagnostic test mode Function
Bulb check MIL can be checked.
SRT status ECM can read if SRT codes are set.
Malfunction warning If ECM detects a malfunction, it illuminates or blinks MIL to inform the driver that a malfunction has been detected.
Self-diagnostic results DTCs or 1st trip DTCs stored in ECM can be read.
Accelerator pedal released po-
sition learning ECM can learn the accelerator pedal released position. Refer to
EC-177, "Work Procedure"
.
Throttle valve closed position
learning ECM can learn the throttle valve closed position. Refer to
EC-178, "Work Procedure"
.
Idle air volume learning ECM can learn the idle air volume. Refer to EC-179, "Work Procedure"
.
Mixture ratio self -learning value
clear Mixture ratio self-learning value can be erased. Refer to
EC-181, "Work Procedure"
.
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EC-86
< SYSTEM DESCRIPTION >[QR25DE]
DIAGNOSIS SYSTEM (ECM)
*: Leaving cooling fan OFF with CONSULT while engine is running may cause the engine to overheat.
DTC WORK SUPPORT MODE
DTC WORK SUPPORT Mode
ALTERNATOR
DUTY • Engine: Idle
• Change duty ratio using CON-
SULT. Battery voltage changes.
• Harness and connectors
•IPDM E/R
•Alternator
FUEL PUMP RELAY • Ignition switch: ON (Engine
stopped)
• Turn the fuel pump relay “ON”
and “OFF” using CONSULT and
listen to operating sound. Fuel pump relay makes the operat-
ing sound. • Harness and connectors
• Fuel pump relay
VIAS S/V-1 • Ignition switch: ON
• Turn intake manifold tuning valve
“ON” and “OFF” using CONSULT
and listen to operating sound. Intake manifold tuning valve motor
makes an operating sound. • Harness and connectors
• Intake manifold tuning valve mo- tor
TUMBLE CONTROL
VA LV E • Ignition switch: ON
• Turn intake manifold runner con-
trol valve “ON” and “OFF” using
CONSULT and listen to operating
sound. Intake Manifold Runner control
valve motor makes an operating
sound. • Harness and connectors
• Intake Manifold Runner control valve motor
IGNITION TIMING • Engine: Return to the original
trouble condition
• Timing light: Set
• Retard the ignition timing using
CONSULT. If trouble symptom disappears, see
CHECK ITEM. • Perform Idle Air Volume Learn-
ing.
POWER BALANCE • Engine: After warming up, idle the
engine.
• A/C switch OFF
• Selector lever: P or N
• Cut off each fuel injector signal one at a time using CONSULT. Engine runs rough or stops. • Harness and connectors
• Compression
• Fuel injector
• Power transistor
• Spark plug
• Ignition coil
VENT CONTROL/V • Ignition switch: ON (Engine
stopped)
• Turn solenoid valve “ON” and “OFF” using CONSULT and listen
to operating sound. Solenoid valve makes an operating
sound. • Harness and connectors
• Solenoid valve
INT V/T ASSIGN AN-
GLE • Engine: Return to the original
trouble condition
• Change intake valve timing using
CONSULT. If trouble symptom disappears, see
CHECK ITEM. • Harness and connectors
• Intake valve timing control sole- noid valve
EXH V/T ASSIGN
ANGLE • Engine: Return to the original
trouble condition
• Change exhaust valve timing us- ing CONSULT. If trouble symptom disappears, see
CHECK ITEM. • Harness and connectors
• Exhaust valve timing control so-
lenoid valve
COOLING FAN* • Ignition switch: ON
• Turn the cooling fan “LOW”, “HI” and “OFF” using CONSULT. Cooling fan moves and stops. • Harness and connectors
• IPDM E/R (Cooling fan relay)
• Cooling fan motor
Test item Condition Judgment Check item (Remedy)
Test mode Test item Corresponding DTC No. Reference page
EVAPORATIVE SYSTEM PURG FLOW P0441 P0441
EC-337
PURG VOL CN/V P1444 P0443EC-342
A/F SEN1 A/F SEN1(B1) P1276 P0130 EC-258
HO2S2HO2S2(B1) P1146 P0138
EC-274HO2S2(B1) P1147 P0137EC-268
HO2S2(B1) P0139 P0139EC-282
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EC-102
< ECU DIAGNOSIS INFORMATION >[QR25DE]
ECM
DTC RELATED ITEM
Description
When a DTC is detected, ECM executes a mode (in the
Fail-safe mode) applicable to the DTC. The fail-safe
mode has the preset traveling control mode (acceler ator angle variation and engine output limit) and device fix
mode.
Fail Safe Pattern
Fail Safe List
× :Applicable —: Not applicable
Detected
items Engine operating condition
in fail-safe mode Remarks Reference page
Malfunction
indicator
lamp circuit Engine speed will not rise
more than 2,500 rpm due
to the fuel cut When there is an open circuit on MIL circuit, the ECM cannot warn the
driver by lighting up MIL when there is malfunction on engine control
system.
Therefore, when electrical controlled throttle and part of ECM related
diagnoses are continuously detected as NG for 5 trips, ECM warns the
driver that engine control system malfunctions and MIL circuit is open
by means of operating fail safe function.
The fail safe function also operates when above diagnoses except MIL
circuit are detected and demands the driver to repair the malfunction. EC-517, "Compo-
nent Function
Check"
Fail safe mode Vehicle behavior
Traveling con-
trol mode Accelerator an-
gle variation
control ECM controls the accelerator pedal depression speed to make it slower than actual speed. This
causes a drop in accelerating performance and encourages the driver to repair malfunction.
NOTE:
ECM does not control the accelerator pedal releasing speed.
Engine output
control ECM reduces the engine output, according to the rise in engine speed. This reduces the vehicle
speed to encourage the driver to repair malfunction.
Device fix mode • This mode fixes the IVT control solenoid valve and the EVT control solenoid valve in the refer-
ence position.
• The intake manifold runner control valve motor is turned OFF (intake manifold runner control
valve opens).
Pattern Fail safe mode
A Traveling control mode Accelerator angle variation control
B Engine output control
C Device fix mode
DTC No. Detected items Vehicle behavior
Pattern Others
ABC
P0011 Intake valve timing control ——×ECM activates the IVT intermediate lock control solenoid
valve to bring the cam sprocket into an intermediate lock con-
dition.
P0014
P0078 Exhaust valve timing control
——× —
P0101
P0102
P0103 Mass air flow sensor circuit
××× —
P0122
P0123
P0222
P0223
P2135 Throttle position sensor
———The ECM controls the electric throttle control actuator in reg-
ulating the throttle opening in order for the idle position to be
within +10 degrees.
The ECM regulates the opening speed of the throttle valve to
be slower than the normal condition.
So, the acceleration will be poor.
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EC-172
< BASIC INSPECTION >[QR25DE]
BASIC INSPECTION
2. Check ignition timing with a timing light.
For procedure, refer to EC-535, "Inspection"
For specification, refer to EC-541, "Ignition Timing".
Is the inspection result normal?
YES >> INSPECTION END.
NO >> GO TO 11.
11 .PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-177, "Work Procedure"
.
>> GO TO 12.
12.PERFORM THROTTLE VALVE CL OSED POSITION LEARNING
Perform EC-178, "Work Procedure"
.
>> GO TO 13.
13.PERFORM IDLE AIR VOLUME LEARNING
Perform EC-179, "Work Procedure"
.
Is Idle Air Volume Learning carried out successfully?
YES >> GO TO 14.
NO >> Follow the instruction of Idle Air Volume Learning. Then GO TO 4.
14.CHECK TARGET IDLE SPEED AGAIN
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
For procedure, refer to EC-534, "Inspection"
.
For specification, refer to EC-541, "Idle Speed"
.
Is the inspection result normal?
YES >> GO TO 15.
NO >> GO TO 17.
15.CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light. For procedure, refer to EC-535, "Inspection"
.
For specification, refer to EC-541, "Ignition Timing"
.
Is the inspection result normal?
YES >> INSPECTION END.
NO >> GO TO 16.
16.CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-62, "Removal and Installation"
.
Is the inspection result normal?
YES >> GO TO 17.
NO >> Repair the timing chain installation. Then GO TO 4.
Timing indicator
JPBIA5854ZZ
Timing indicator
JPBIA5854ZZ
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TROUBLE DIAGNOSIS - SPECIFICATION VALUEEC-195
< DTC/CIRCUIT DIAGNOSIS > [QR25DE]
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DTC/CIRCUIT DIAGNOSIS
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DescriptionINFOID:0000000009462149
The specification (SP) value indicates the tolerance of
the value that is displayed in “SPEC” of “DATA MONI-
TOR” mode of CONSULT during normal operation of the Engine Control System. When the value in “SPEC” of
“DATA MONITOR” mode is within the SP value, the E ngine Control System is confirmed OK. When the value
in “SPEC” of “DATA MONITOR” mode is NOT within t he SP value, the Engine Control System may have one
or more malfunctions.
The SP value is used to detect malfunctions that may af fect the Engine Control System, but will not light the
MIL.
The SP value will be displayed for the following three items:
• B/FUEL SCHDL (The fuel injection pulse width programmed into ECM prior to any learned on board correc- tion)
• A/F ALPHA-B1 (The mean value of air-fuel ratio feedback correction factor per cycle)
• MAS A/F SE-B1 (The signal voltage of the mass air flow sensor)
Component Function CheckINFOID:0000000009462150
1.START
Make sure that all of the following conditions are satisfied.
• Vehicle driven distance: More than 5,000 km (3,107 miles)
• Barometric pressure: 98.3 - 104.3 kPa (1.003 - 1.064 kg/cm
2, 14.25 - 15.12 psi)
• Atmospheric temperature: 20 - 30 °C (68 - 86 °F)
• Engine coolant temperature: 75 - 95 °C (167 - 203 °F)
• Transmission: Warmed-up
- After the engine is warmed up to normal operating tem perature, drive vehicle until “ATF TEMP SEN” (CVT
fluid temperature sensor signal) indicates more than 60 °C (140 °F).
• Electrical load: Not applied*
• Engine speed: Idle
*: Rear window defogger switch, air conditioner switch, lighting switch are OFF. Steering wheel is straight
ahead.
>> GO TO 2.
2.PERFORM “SPEC” OF “DATA MONITOR” MODE
With CONSULT
NOTE:
Perform “SPEC” in “DATA MONITOR” mode in maximum scale display.
1. Perform EC-170, "Work Procedure"
.
2. Select “B/FUEL SCHDL”, “A/F ALPHA-B1” and “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode
with CONSULT.
3. Make sure that monitor items are within the SP value.
Is the inspection result normal?
YES >> END
NO >> Proceed to EC-196, "Diagnosis Procedure"
.
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EC-228
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0101 MAF SENSOR
P0101 MAF SENSOR
DTC LogicINFOID:0000000009462178
DTC DETECTION LOGIC
NOTE:
If DTC P0101 is displayed with other DTC, fi rst perform the trouble diagnosis for other DTC.
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC CONFIRMATION PROCEDURE has been previously conducted, always perform the following proce-
dure before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and warm it up to normal operating temperature.
2. Drive the vehicle for at least 5 seconds under the following conditions: CAUTION:
Always drive vehicle at safe speed.
NOTE:
• The gear must be fixed while driving the vehicle.
• Keep the accelerator pedal as st eady as possible during cruising.
3. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-228, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000009462179
1.CHECK INTAKE SYSTEM
Check the following for connection.
• Air duct
• Vacuum hoses
• Intake air passage between air duct and intake manifold
Is the inspection result normal?
YES >> GO TO 2.
NO >> Reconnect the parts.
2.CHECK MASS AIR FLOW (M AF) SENSOR POWER SUPPLY
DTC No.CONSULT screen terms
(Trouble diagnosis content) DTC detecting condition Possible cause
P0101 MAF SEN/CIRCUIT-B1
(Mass or volume air Flow ″A ″
circuit range/performance) • A high voltage from the sensor is sent to
ECM under light load driving condition.
• A low voltage from the sensor is sent to ECM under heavy load driving condition. • Harness or connectors
(MAF sensor circuit is open or short-
ed.)
• Intake air leaks
• MAF sensor
• EVAP control system pressure sensor
• Intake air temperature sensor
• Sensor power supply 2 circuit
Selector lever Suitable position
Vehicle speed 40 km/h (25 MPH) or more
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EC-294
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0171 FUEL INJECTION SYSTEM FUNCTION
P0171 FUEL INJECTIO
N SYSTEM FUNCTION
DTC LogicINFOID:0000000009462234
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio f eedback signal from the A/F sensors 1. The ECM calcu-
lates the necessary compensation to correct the of fset between the actual and the theoretical ratios.
In case the amount of the compensation value is extrem ely large (The actual mixture ratio is too lean.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-1
1. Clear the mixture ratio self-learning value. Refer to EC-181, "Work Procedure"
.
2. Start engine.
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the f uel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three-fourths (3/4 ) or more, the control system does not start the
engine. Do not depress accelerator pedal too much.
Does engine start?
YES >> Proceed to EC-295, "Diagnosis Procedure".
NO >> Check exhaust and intake air leak visually.
4.PERFORM DTC CONFIRMATION PROCEDURE-2
1. Start engine and let it idle for at least 5 minutes.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
Sensor Input signal to ECM ECM function Actuator
A/F sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal) Fuel injection control Fuel injector
DTC No.CONSULT screen terms
(Trouble diagnosis content) DTC detecting condition Possible cause
P0171 FUEL SYS-LEAN-B1
(System too lean bank 1) • Fuel injection system does not operate properly.
• The amount of mixture ratio compensation is too
large. (The mixture ratio is too lean.) • Intake air leaks
• A/F sensor 1
• Fuel injector
• Exhaust gas leaks
• Incorrect fuel pressure
• Lack of fuel
• Mass air flow sensor
• Incorrect PCV hose connection
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EC-298
< DTC/CIRCUIT DIAGNOSIS >[QR25DE]
P0172 FUEL INJECTION SYSTEM FUNCTION
P0172 FUEL INJECTIO
N SYSTEM FUNCTION
DTC LogicINFOID:0000000009462236
DTC DETECTION LOGIC
With the Air/Fuel Mixture Ratio Self-Learning Control, the actual mixture ratio can be brought closely to the
theoretical mixture ratio based on the mixture ratio f eedback signal from the A/F sensors 1. The ECM calcu-
lates the necessary compensation to correct the of fset between the actual and the theoretical ratios.
In case the amount of the compensation value is extrem ely large (The actual mixture ratio is too rich.), the
ECM judges the condition as the fuel injection system malfunction and lights up the MIL (2 trip detection logic).
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure
before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE-1
1. Clear the mixture ratio self-learning value. Refer to EC-181, "Work Procedure"
.
2. Start engine.
Is it difficult to start engine?
YES >> GO TO 3.
NO >> GO TO 4.
3.RESTART ENGINE
If it is difficult to start engine, the f uel injection system has a malfunction, too.
Crank engine while depressing accelerator pedal.
NOTE:
When depressing accelerator pedal three-fourths (3/4 ) or more, the control system does not start the
engine. Do not depress accelerator pedal too much.
Does engine start?
YES >> Proceed to EC-299, "Diagnosis Procedure".
NO >> Check exhaust and intake air leak visually.
4.PERFORM DTC CONFIRMATION PROCEDURE-2
1. Start engine and let it idle for at least 5 minutes.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Proceed to EC-299, "Diagnosis Procedure".
NO >> GO TO 5.
Sensor Input signal to ECM ECM function Actuator
A/F sensor 1 Density of oxygen in exhaust gas
(Mixture ratio feedback signal) Fuel injection control Fuel injector
DTC No.CONSULT screen terms
(Trouble diagnosis content) DTC detecting condition Possible cause
P0172 FUEL SYS-RICH-B1
(System too rich bank 1) • Fuel injection system does not operate properly.
• The amount of mixture ratio compensation is too
large. (The mixture ratio is too rich.) • A/F sensor 1
• Fuel injector
• Exhaust gas leaks
• Incorrect fuel pressure
• Mass air flow sensor
Revision: November 20132014 Altima NAMRevision: November 20132014 Altima NAM