Mass air flow sensor INFINITI FX35 2008 User Guide

EC-98
< SERVICE INFORMATION >[VQ35DE]
TROUBLE DIAGNOSIS
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA
Fuel Fuel tank 5
5 FL-10
Fuel piping 5 5 5 5 5 5
EM-45
Va p o r l o c k —
Valve deposit 5 555 55 5 —
Poor fuel (Heavy weight gasoline,
Low octane) —
Air Air duct
55555 5 EM-17
Air cleaner
EM-17
Air leakage from air duct
(Mass air flow sensor — electric
throttle control actuator)
5555 EM-17
Electric throttle control actuator
EM-19
Air leakage from intake manifold/
Collector/GasketEM-19,
EM-24
Cranking Battery 111111
11
SC-4
Generator circuit
SC-19
Starter circuit 3SC-8
Signal plate 6EM-122
Park/neutral position (PNP)
switch4
AT- 1 0 2
Engine Cylinder head
55555 55 5 EM-100
Cylinder head gasket 4 3
Cylinder block
66666 66 6 4
EM-122
Piston
Piston ring
Connecting rod
Bearing
Crankshaft
Va l v e
mecha-
nism Timing chain
55555 55 5 EM-64
Camshaft
EM-83
Intake valve timing controlEM-64
Intake valve
3EM-100
Exhaust valve
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EC-114
< SERVICE INFORMATION >[VQ35DE]
TROUBLE DIAGNOSIS
51 L/W Mass air flow sensor[Engine is running]

Warm-up condition
 Idle speed 1.0 - 1.2V
[Engine is running]
 Warm-up condition
 Engine speed: 2,500 rpm 1.6 - 2.0V
55 W/R Heated oxygen sensor 2
(bank 2) [Engine is running]
 Revving engine from idle to 3,000 rpm quick-
ly after the following conditions are met
- Engine: After warming up
- Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load 0 - Approximately 1.0V
57 G A/F sensor 1 (Bank 2) [Engine is running]

Warm-up condition
 Idle speed Approximately 2.6V
58 Y Approximately 2.3V
76 P Approximately 3.1V
77 BR Approximately 2.3V
60
61
62 PU
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Y Ignition signal No. 5
Ignition signal No. 3
Ignition signal No. 1 [Engine is running]

Warm-up condition
 Idle speed NOTE:
The pulse cycle changes depending on rpm
at idle 0 - 0.2V
[Engine is running]
 Warm-up condition
 Engine speed: 2,500 rpm 0.1 - 0.4V
66 B Sensor ground
(Throttle position sensor) [Engine is running]

Warm-up condition
 Idle speed Approximately 0V
67 B/W Sensor ground [Engine is running]

Warm-up condition
 Idle speed Approximately 0V
68 BR Sensor power supply
(Power steering pressure
sensor) [Ignition switch: ON]
Approximately 5V
69 R Throttle position sensor 2 [Ignition switch: ON]
 Engine stopped
 Selector lever: D
 Accelerator pedal: Fully released
Less than 4.75V
[Ignition switch: ON]
 Engine stopped
 Selector lever: D
 Accelerator pedal: Fully depressed More than 0.36V
70 L/R Refrigerant pressure sensor [Engine is running]

Warm-up condition
 Both A/C switch and blower fan switch: ON (Compressor operates) 1.0 - 4.0V
TER-
MI-
NAL NO. WIRE
COLOR
ITEM CONDITION DATA (DC Voltage)
SEC986C
SEC987C
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EC-118
< SERVICE INFORMATION >[VQ35DE]
TROUBLE DIAGNOSIS
ItemDIAGNOSTIC TEST MODE
WORK SUP-
PORT SELF-DIAGNOSTIC
RESULTS DATA
MONI-
TOR ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*
1FREEZE FRAME
DATA*
1
SRT
STATUS DTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS) ×××
Camshaft position sensor (PHASE) ×××
Mass air flow sensor ××
Engine coolant temperature sensor ××××
Air fuel ratio (A/F) sensor 1 ××××
Heated oxygen sensor 2 ××××
Vehicle speed sensor ×××
Accelerator pedal position sensor ××
Throttle position sensor ×××
Fuel tank temperature sensor ×××
EVAP control system pressure sen-
sor ××
Intake air temperature sensor ×××
Knock sensor ×
Refrigerant pressure sensor ×
Closed throttle position switch (ac-
celerator pedal position sensor sig-
nal) ×
Air conditioner switch ×
Park/neutral position (PNP) switch ××
Stop lamp switch ××
Power steering pressure sensor ××
Battery voltage ×
Load signal ×
Fuel level sensor ××
ICC steering switch ××
ASCD steering switch ××
ICC brake switch ××
ASCD brake switch ××
Snow mode switch ×
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TROUBLE DIAGNOSISEC-121
< SERVICE INFORMATION > [VQ35DE]
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*: The items are the same as those of 1st trip freeze frame data.
DATA MONITOR MODE
Monitored Item
×
: Applicable
INT/A TEMP SE
[° C] or [ °F]  The intake air temperature at the moment a malfunction is detected is displayed.
INT MANI PRES [kPa]  Always a certain value is displayed.
 These items are not efficient for S50 models.
FTFMCH1 Freeze frame data
item* Description
Monitored item Unit Description Remarks
ENG SPEED rpm  Indicates the engine speed computed from the sig-
nal of the crankshaft position sensor (POS) and
camshaft position sensor (PHASE).  Accuracy becomes poor if engine speed
drops below the idle rpm.
 If the signal is interrupted while the en-
gine is running, an abnormal value may
be indicated.
MAS A/F SE-B1 × The signal voltage of the mass air flow sensor is
displayed.  When the engine is stopped, a certain
value is indicated.
B/FUEL SCHDL × Base fuel schedule indicates the fuel injection
pulse width programmed into ECM, prior to any
learned on board correction.
A/F ALPHA-B1 %  The mean value of the air-fuel ratio feedback cor-
rection factor per cycle is indicated.  When the engine is stopped, a certain
value is indicated.
 This data also includes the data for the air-fuel ratio learning control.
A/F ALPHA-B2
×
COOLAN TEMP/S °C or ° The engine coolant temperature (determined by
the signal voltage of the engine coolant tempera-
ture sensor) is displayed.  When the engine coolant temperature
sensor is open or short-circuited, ECM
enters fail-safe mode. The engine cool-
ant temperature determined by the ECM
is displayed.
A/F SEN1 (B1) ×
 The A/F signal computed from the input signal of
the Air fuel ratio (A/F) sensor 1 is displayed.
A/F SEN1 (B2) ×
HO2S2 (B1) ×
 The signal voltage of the heated oxygen sensor 2 is
displayed.
HO2S2 (B2) ×
HO2S2 MNTR(B1) RICH/
LEAN  Display of heated oxygen sensor 2 signal:
RICH: means the amount of oxygen after three way
catalyst is relatively small.
LEAN: means the amount of oxygen after three
way catalyst is relatively large.  When the engine is stopped, a certain
value is indicated.
HO2S2 MNTR(B2) RICH/
LEAN
VHCL SPEED SE km/h or
mph  The vehicle speed computed from the vehicle
speed signal sent from combination meter is dis-
played.
BATTERY VOLT V  The power supply voltage of ECM is displayed.
ACCEL SEN 1 ×
 The accelerator pedal position sensor signal volt-
age is displayed.  ACCEL SEN 2 signal is converted by
ECM internally. Thus, it differs from ECM
terminal voltage signal.
ACCEL SEN 2
×
TP SEN 1-B1 V  The throttle position sensor signal voltage is dis-
played.  THRTL SEN 2 signal is converted by
ECM internally. Thus, it differs from ECM
terminal voltage signal.
TP SEN 2-B1 V
FUEL T/TMP SE
°C or ° The fuel temperature (determined by the signal
voltage of the fuel tank temperature sensor) is dis-
played.
INT/A TEMP SE °C or °F  The intake air temperature (determined by the sig-
nal voltage of the intake air temperature sensor) is
indicated.
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EC-122
< SERVICE INFORMATION >[VQ35DE]
TROUBLE DIAGNOSIS
EVAP SYS PRES V The signal voltage of EVAP control system pres-
sure sensor is displayed.
FUEL LEVEL SE V  The signal voltage of the fuel level sensor is dis-
played.
START SIGNAL × Indicates start signal status [ON/OFF] computed by
the ECM according to the signals of engine speed
and battery voltage.  After starting the engine, [OFF] is dis-
played regardless of the starter signal.
CLSD THL POS × Indicates idle position [ON/OFF] computed by ECM
according to the accelerator pedal position sensor
signal.
AIR COND SIG × Indicates [ON/OFF] condition of the air conditioner
switch as determined by the air conditioner signal.
P/N POSI SW × Indicates [ON/OFF] condition from the park/neutral
position (PNP) switch signal.
PW/ST SIGNAL × [ON/OFF] condition of the power steering system
(determined by the signal voltage of the power
steering pressure sensor) is indicated.
LOAD SIGNAL × Indicates [ON/OFF] condition from the electrical
load signal.
ON: Rear window defogger switch is ON and/or
lighting switch is in 2nd position.
OFF: Both rear window defogger switch and light-
ing switch are OFF.
IGNITION SW × Indicates [ON/OFF] condition from ignition switch
signal.
HEATER FAN SW × Indicates [ON/OFF] condition from the heater fan
switch signal.
BRAKE SW × Indicates [ON/OFF] condition from the stop lamp
switch signal.
INJ PULSE-B1 ×
 Indicates the actual fuel injection pulse width com-
pensated by ECM according to the input signals.  When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2 ×
IGN TIMING × Indicates the ignition timing computed by ECM ac-
cording to the input signals.  When the engine is stopped, a certain
value is indicated.
CAL/LD VALUE %  Calculated load value indicates the value of the cur-
rent air flow divided by peak air flow.
MASS AIRFLOW g·m/s  Indicates the mass air flow computed by ECM ac-
cording to the signal voltage of the mass air flow
sensor.
PURG VOL C/V %  Indicates the EVAP canister purge volume control
solenoid valve control value computed by the ECM
according to the input signals.
 The opening becomes larger as the value increas- es.
INT/V TIM(B1) °CA
 Indicates [ °CA] of intake camshaft advanced angle.
INT/V TIM(B2) °CA
INT/V SOL(B1) %  The control condition of the intake valve timing con- trol solenoid valve (determined by ECM according
to the input signals) is indicated.
 The advance angle becomes larger as the value in-
creases.
INT/V SOL(B2) %
AIR COND RLY
× The air conditioner relay control condition (deter-
mined by ECM according to the input signals) is in-
dicated.
FUEL PUMP RLY × Indicates the fuel pump relay control condition de-
termined by ECM according to the input signals.
Monitored item Unit Description Remarks
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TROUBLE DIAGNOSIS - SPECIFICATION VALUEEC-131
< SERVICE INFORMATION > [VQ35DE]
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TROUBLE DIAGNOSIS - SPECIFICATION VALUE
DescriptionINFOID:0000000001325940
The specification (SP) value indicates the tolerance of
the value that is displayed in “SPEC” of “DATA MONI-
TOR” mode of CONSULT-III during normal operation of the Engine Control System. When the value in “SPEC”
of “DATA MONITOR” mode is within the SP value, the Engine Control System is confirmed OK. When the
value in “SPEC” of “DATA MONITOR” mode is NOT withi n the 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/B2 (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)
Testing ConditionINFOID:0000000001325941
 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 temperat ure, drive vehicle until “ATF TEMP 1” (A/T fluid
temperature sensor signal) indicates more than 60 °C (140 °F).
 Electrical load: Not applied
- Rear window defogger switch, air conditioner switch, li ghting switch are OFF. Steering wheel is straight
ahead.
 Engine speed: Idle
Inspection ProcedureINFOID:0000000001325942
NOTE:
Perform “SPEC” in “DATA MONITOR” mode in maximum scale display.
1. Perform EC-80, "
Basic Inspection".
2. Confirm that the testing conditions indicated above are met.
3. Select “B/FUEL SCHDL”, “A/F ALPHA-B1”, “A/F ALPHA-B2” and “MAS A/F SE-B1” in “SPEC” of “DATA
MONITOR” mode with CONSULT-III.
4. Make sure that monitor items are within the SP value.
5. If NG, go to EC-131, "
Diagnosis Procedure".
Diagnosis ProcedureINFOID:0000000001325943
OVERALL SEQUENCE
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EC-136
< SERVICE INFORMATION >[VQ35DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
OK >>
INSPECTION END
NG >> GO TO 15.
15.DISCONNECT AND RECONNE CT ECM HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
16.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-96, "
Symptom Matrix Chart".
17.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> INSPECTION END
NG (More than the SP value)>>GO TO 18.
NG (Less than the SP value)>>GO TO 25.
18.DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
- Engine oil level is too high
- Engine oil viscosity
- Belt tension of power steering, alternat or, A/C compressor, etc. is excessive
- Noise from engine
- Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
- Valve clearance malfunction
- Intake valve timing control function malfunction
- Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
 Crushed air ducts
 Malfunctioning seal of air cleaner element
 Uneven dirt of air cleaner element
 Improper specification of intake air system
OK or NG
OK >> GO TO 21.
NG >> Repair or replace malfunctioning part, and then GO TO 20.
20.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/F UEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG (“B/FUEL SCHDL” is more, “A/F ALPHA-B1”, “A/F ALPHA-B2” are less than the SP value)>>GO TO 21.
21.DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
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TROUBLE DIAGNOSIS - SPECIFICATION VALUEEC-137
< SERVICE INFORMATION > [VQ35DE]
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2. Disconnect mass air flow sensor harness connecto
r. Check pin terminal and connector for damage and
then reconnect it again.
>> GO TO 22.
22.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> 1. Detect malfunctioning part of mass air flow sensor circuit and repair it. Refer to EC-182
.
2. GO TO 29.
NG >> GO TO 23.
23.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> GO TO 24.
NG (More than the SP value)>>Replace ma ss air flow sensor, and then GO TO 29.
24.REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS(NATS) system and registration of all IVIS(NATS) ignition key IDs.
Refer to BL-187, "
ECM Re-Communicating Function".
3. Perform EC-84, "
VIN Registration".
4. Perform EC-85, "
Accelerator Pedal Released Position Learning".
5. Perform EC-85, "
Throttle Valve Closed Position Learning".
6. Perform EC-85, "
Idle Air Volume Learning".
>> GO TO 29.
25.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
 Crushed air ducts
 Malfunctioning seal of air cleaner element
 Uneven dirt of air cleaner element
 Improper specification of intake air system
OK or NG
OK >> GO TO 27.
NG >> Repair or replace malfunctioning part, and then GO TO 26.
26.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” m ode, and make sure that the indication is within the
SP value.
OK or NG
OK >> INSPECTION END
NG (Less than the SP value)>>GO TO 27.
27.CHECK “MAS A/F SE-B1”
Select “MAS A/F SE-B1” in “SPEC” of “DATA MONITOR” mode, and make sure that the indication is within the
SP value.
OK or NG
OK >> GO TO 28.
NG (Less than the SP value)>>Replace ma ss air flow sensor, and then GO TO 30.
28.CHECK INTAKE SYSTEM
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EC-138
< SERVICE INFORMATION >[VQ35DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
Check for the cause of air leak after the mass air flow sensor. Refer to the following.
 Disconnection, looseness, and cracks in air duct
 Looseness of oil filler cap
 Disconnection of oil level gauge
 Open stuck, breakage, hose disconnecti
on, or cracks of PCV valve
 Disconnection or cracks of EVAP purge hose, open stuc k of EVAP canister purge volume control solenoid
valve
 Malfunctioning seal of rocker cover gasket
 Disconnection, looseness, or cracks of hoses, such as vacuum hose, connecting to intake air system parts
 Malfunctioning seal of intake air system, etc.
>> GO TO 30.
29.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/F UEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and
make sure that the each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-96, "
Symptom Matrix Chart".
30.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITO R” mode, and then make sure that the indication is
within the SP value.
OK or NG
OK >> INSPECTION END
NG >> Detect malfunctioning part according to EC-96, "
Symptom Matrix Chart".
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DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
EC-153
< SERVICE INFORMATION > [VQ35DE]
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DTC P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
DescriptionINFOID:0000000001325965
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the air fuel
ratio (A/F) sensor 1 heater corresponding to the engine
operating condition to keep the temperature of air fuel ratio (A/F) sensor 1 element at the specified range.
CONSULT-III Reference Val ue in Data Monitor ModeINFOID:0000000001325966
Specification data are reference values.
On Board Diagnosis LogicINFOID:0000000001325967
DTC Confirmation ProcedureINFOID:0000000001325968
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is between 10.5V and 16V at
idle.
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-157, "
Diagnosis Procedure".
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS) Engine speed
Air fuel ratio (A/F) sensor 1
heater control Air fuel ratio (A/F) sensor 1 heater
Mass air flow sensor Amount of intake air
MONITOR ITEM CONDITION SPECIFICATION
A/F S1 HTR(B1)
A/F S1 HTR(B2)  Engine: After warming up, idle the engine 0 - 100%
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0031
0031
(Bank 1) Air fuel ratio (A/F) sensor
1 heater control circuit low The current amperage in the heated air fuel ratio (A/
F) sensor 1 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)  Harness or connectors
[Air fuel ratio (A/F) sensor 1 heater cir-
cuit is open or shorted.]
 Air fuel ratio (A/F) sensor 1 heater
P0051
0051
(Bank 2)
P0032
0032
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater control circuit
high The current amperage in the heated air fuel ratio (A/
F) sensor 1 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)  Harness or connectors
[Air fuel ratio (A/F) sensor 1 heater cir-
cuit is shorted.]
 Air fuel ratio (A/F) sensor 1 heater
P0052
0052
(Bank 2)
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