1996 TOYOTA LAND CRUISER Air flow sensor

 DTC No.
Indicates the diagnostic trouble code.
 Page or Instructions
Indicates the page where the inspection procedure
for each circuit is to be found, or gives instructions
for checking and repairs. Detection Item
Indicates the system of the problem or
contents of the problem.  Trouble Area
Indicates the suspect area of the
problem.
Mass
Air Flow Circuit MalfunctionDetection Item
 Open or short in mass air flow meter circuit
 Mass air flow meter
 ECM
DTC No.
(See page)
Trouble Area
MIL* MemoryP0100
(DI−24)
P0101
(DI−28)
P0115
(DI−33)  Open or short in intake air temp. sensor
circuit
 Intake air temp. sensor
 ECM
Intake Air Temp. Circuit
Malfunction
P0110
(DI−29)
 Open or short in engine coolant temp. sensor circuit
 Engine coolant temp. sensor
 ECM
Throttle/ Pedal Position Sensor/Switch
”A” Circuit MalfunctionEngine Coolant Temp.
Circuit Malfunction
 Open or short in throttle position sensor circuit
 Throttle position sensor
 ECM
HINT:
Parameters listed in the chart may not be exactly the same as your readi\
ng due to the type of instrument or other
factors.
If a malfunction code is displayed during the DTC check mode, check the circ\
uit for the code listed in the table
below. For details of each code, turn to the page referred to under the ”See\
page” for the respective ”DTC No.”
in the DTC chart.
Mass Air Flow Circuit
Range/ Performance Problem Mass air flow meter
 Throttle position sensor
Throttle/
Pedal Position Sensor/ Switch
”A” Circuit Range / Performance Prob-
lem
P0116
(DI−37)
Engine Coolant Temp.
Circuit
Range/ Performance Problem Engine coolant temp. sensor
 Cooling system
SAE CONTROLLED
DIAGNOSTIC TROUBLE CODE CHART
IN−24−
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 LAND CRUISER (RM451U)
4. DIAGNOSTIC TROUBLE CODE CHART
The inspection procedure is shown in the table below. This ta ble permits efficient and accurate troubleshoot-
ing using the diagnostic trouble codes displayed in the diagnostic trouble code check. Proceed with trouble-
shooting in accordance with the inspection procedure given in the diagnostic cha\
rt corresponding to the
diagnostic trouble codes displayed. The engine diagnostic trouble code chart is sho\
wn below as an example.
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−
INTRODUCTION TERMS
IN−39
1996 LAND CRUISER (RM451U)
HO2S
Heated Oxygen SensorHeated Oxygen Sensor (HO2S)
IACIdle Air ControlIdle Speed Control (ISC)
IATIntake Air TemperatureIntake or Inlet Air T
emperature
ICMIgnition Control Module−
IFIIndirect Fuel InjectionIndirect Injection (IDL)
IFSInertia Fuel−Shutoff−
ISCIdle Speed Control−
KSKnock SensorKnock Sensor
MAFMass Air FlowAir Flow Meter
MAPManifold Absolute PressureManifold Pressure
Intake V acuum
MCMixture Control
Electric Bleed Air Control Valve (EBCV)
Mixture Control Valve (MCV)
Electric Air Control Valve (EACV)
MDPManifold Dif ferential Pressure−
MFIMultiport Fuel InjectionElectronic Fuel Injection (EFI)
MILMalfunction Indicator LampCheck Engine Lamp
MSTManifold Surface T emperature−
MVZManifold Vacuum Zone−
NVRAMNon−Volatile Random Access Memory−
O2SOxygen SensorOxygen Sensor, O2 Sensor (O2S)
OBDOn−Board DiagnosticOn− Board Diagnostic System (OBD)
OCOxidation Catalytic ConverterOxidation Catalyst Convert (OC), CCo
OPOpen LoopOpen Loop
PAIRPulsed Secondary Air InjectionAir Suction (AS)
PCMPowertrain Control Module−
PNPPark/Neutral Position−
PROMProgrammable Read Only Memory−
PSPPower Steering Pressure−
PTOXPeriodic Trap OxidizerDiesel Particulate Filter (DPF)
Diesel Particulate Trap (DPT)
RAMRandom Access MemoryRandom Access Memory (RAM)
RMRelay Module−
ROMRead Only MemoryRead Only Memory (ROM)
RPMEngine SpeedEngine Speed
SCSuperchargerSupercharger
SCBSupercharger BypassE−ABV
SFISequential Multiport Fuel InjectionElectronic Fuel Injection (EFI), Sequential Injection
SPLSmoke Puff Limiter−
SRIService Reminder Indicator−
SRTSystem Readiness Test−
STScan Tool−
TBThrottle BodyThrottle Body
TBIThrottle Body Fuel InjectionSingle Point Injection
Central Fuel Injection (Ci)
TCTurbochargerTurbocharger
TCCTorque Converter ClutchTorque Converter
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IN−40
−
INTRODUCTION TERMS
1996 LAND CRUISER (RM451U)
TCM
Transmission Control ModuleTransmission ECU, ECT ECU
TPThrottle PositionThrottle Position
TRTransmission Range−
TVVThermal Vacuum V
alveBimetallic Vacuum Switching Valve (BVSV)
Thermostatic Vacuum Switching Valve (TVSV)
TWCThree−Way Catalytic Converter
Three−Way Catalytic (TWC)
Manifold Converter
CC
RO
TWC+OCThree−Way + Oxidation Catalytic ConverterCCR + CCo
VA FVolume Air FlowAir Flow Meter
VRVoltage RegulatorVoltage Regulator
VSSVehicle Speed SensorVehicle Speed Sensor
WOTWide Open ThrottleFull Throttle
WU−OCWarm Up Oxidation Catalytic Converter−
WU−TWCWarm Up Three−Way Catalytic Converter−
3GRThird Gear−
4GRFourth Gear−
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−
DIAGNOSTICS ENGINE
DI−11
1996 LAND CRUISER (RM451U)
NG Proceed to page IG−1 and continue to trouble-
shoot.
OK
Proceed to matrix chart of problem symp-
toms on page DI−19.
7. ENGINE OPERATING CONDITION
NOTICE:
The values given below for ”Normal Condition” are representative valu\
es, so a vehicle may still be
normal even if its value varies from those listed here. So do not decide wheth\
er a part is faulty or
not solely according to the ”Normal Condition” here.
(a) CARB mandated signals.
TOYOTA hand−held tester displayMeasurement ItemNormal Condition*
FUEL SYS #1
Fuel System Bank 1
OPEN: Air− fuel ratio feedback stopped
CLOSED: Air− fuel ratio feedback operating
Idling after warming up: CLOSED
CALC LOAD
Calculator Load:
Current intake air volume as a proportion of max.
intake air volumeIdling: 13.8 − 19.3%
Racing without load (2,500 rpm): 17.6 − 25.2%
COOLANT TEMP.Engine Coolant Temp. Sensor ValueAfter warming up: 80 − 95° C (176 − 203°F)
SHORT FT #1Short−term Fuel Trim Bank 10 ± 20%
LONG FT #1Long−term Fuel Trim Bank 10 ± 20%
ENGINE SPDEngine SpeedIdling: 650 ± 50 rpm
VEHICLE SPDVehicle SpeedVehicle Stopped: 0 km/h (0 mph)
IGN ADVANCEIgnition Advance:
Ignition Timing of Cylinder No. 1Idling: BTDC 0 − 11°
INTAKE AIRIntake Air Temp. Sensor V alueEquivalent to Ambient Temp.
MAFAir Flow Rate Through Mass Air Flow Meter
Idling: 4.3 − 6.1 gm/sec.
Racing without load (2,500 rpm):
21.2 − 30.4 gm/sec.
THROTTLE POS
Voltage Output of Throttle Position Sensor
Calculated as a percentage:
0 V → 0%, 5 V →100%Throttle Fully Closed: 7 − 11 %
Throttle Fully Open: 65 − 75%
O2S B1, S1Voltage Output of Oxygen Sensor
Bank 1, Sensor 1Idling: 0.1 − 0.9 V
O2FT B1, S1Oxygen Sensor Fuel Trim Bank 1, Sensor 1
(Same as SHORT FT #1)0 ± 20%
O2S B1, S2Voltage Output of Oxygen Sensor
Bank 1, Sensor 2Driving (50 km/h, 31 mph): 0.1 − 0.9 V
∗: If no conditions are specifically stated for ”ldling”, it means \
the shift lever is at N or P position, the A/C switch
is OFF and all accessory switches are OFF.
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DI5OV−03
−
DIAGNOSTICS ENGINE
DI−13
1996 LAND CRUISER (RM451U)
DIAGNOSTIC TROUBLE CODE CHART
HINT:
Parameters listed in the chart may not be exactly the same as your reading due to \
the type of instrument
or other factors.
If a malfunction code is displayed during the DTC check in check mode, che\
ck the circuit for that code listed
in the table below. For details of each code, turn to the page referred to under the ’’See page ’’ for the respe-
cire ’’DTC No.’’ in the DTC chart.
DTC No.
(See Page)Detection ItemTrouble AreaMILMemory
P0100
( DI−20 )Mass Air Flow Circuit
MalfunctionOpen or short in mass air flow meter circuit
 Mass air flow meter
 ECM
 *1
P0101
( DI−25 )Mass Air Flow Circuit
Range/Performance
Problem
Mass air flow meter *1
P0110
( DI−26 )Intake Air Temp. Circuit
MalfunctionOpen or short in intake air temp. sensor circuit
 Intake air temp. sensor
 ECM
 *1
P0115
( DI−30 )Engine Coolant Temp. Circuit
MalfunctionOpen or short in engine coolant temp. sensor circuit
 Engine coolant temp. sensor
 ECM
 *1
P0116
( DI−34 )Engine Coolant Temp. Circuit
Range/Performance ProblemEngine coolant temp. sensor
 Cooling system *1
P0120
( DI−35 )Throttle/Pedal Position
Sensor/Switch ”A” Circuit
MalfunctionOpen or short in throttle position sensor circuit
 Throttle position sensor
 ECM
 *1
P0121
( DI−39 )Throttle/Pedal Position
Sensor/Switch ”A” Circuit
Range/Performance Problem
Throttle position sensor *1
P0125
( DI−40 )Insufficient Coolant Temp. for
Closed Loop Fuel Control Open or short in heated oxygen sensor circuit
 Heated oxygen sensor *1
P0130
( DI−43 )Heated Oxygen Sensor Circuit
Malfunction (Bank 1 Sensor 1)Heated oxygen sensor
 Fuel trim malfunction *1
P0133
( DI−46 ) Heated Oxygen Sensor Circuit
Slow Response
(Bank 1 Sensor 1)
Heated oxygen sensor *1
P0135
( DI−47 ) Heated Oxygen Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 1)Open or short in heater circuit of heated oxygen sensor
 Heated oxygen sensor heater
 ECM
 *1
P0136
( DI−49 )Heated Oxygen Sensor Circuit
Malfunction
(Bank 1 Sensor 2)
Heated oxygen sensor *1
P0141
( DI−47 ) Heated Oxygen Sensor Heater
Circuit Malfunction
(Bank 1 Sensor 2)
Same as DTC No. P0135 *1
*1: MIL lights up
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DI−14
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC No.
(See Page)
Detection ItemTrouble AreaMILMemory
P0171
( DI−51 )System too Lean
(Fuel T rim)
Air intake (hose loose)
 Fuel line pressure, leak
 Injector blockage
 Heated oxygen sensor malfunction
 Mass air flow meter
 Engine coolant temp. sensor
 *1
P0172
( DI−51 )System too Rich
(Fuel T rim)
Fuel line pressure
 Injector leak, blockage
 Heated oxygen sensor malfunction
 Mass air flow meter
 Engine coolant temp. sensor
 *1
P0300
( DI−54 )Random/Multiple Cylinder
Misfire DetectedIgnition system
 Injector
 Fuel line pressure
 EGR
 Compression pressure
 Valve clearance not to specification
 Valve timing
 Mass air flow meter
 Engine coolant temp. sensor
 *2
P0301
P0302
P0303
P0304
P0305
P0306
( DI−54 )Misfire Detected
− Cylinder 1
− Cylinder 2
− Cylinder 3
− Cylinder 4
− Cylinder 5
− Cylinder 6
P0325
( DI−59 )Knock Sensor 1 Circuit
MalfunctionOpen or short in knock sensor 1 circuit
 Knock sensor 1 (looseness)
 ECM
 *1
P0330
( DI−59 )Knock Sensor 2 Circuit
MalfunctionOpen or short in knock sensor 2 circuit
 Knock sensor 2 (looseness)
 ECM
 *1
P0335
( DI−62 )Crankshaft Position Sensor
”A” Circuit Malfunction
Open or short in crankshaft position sensor circuit for NE sig-
nal
 Crankshaft position sensor for NE signal
 Starter
 ECM
 *1
P0340
( DI−65 )Camshaft Position Sensor
Circuit MalfunctionOpen or short in camshaft position sensor circuit
 Camshaft position sensor
 ECM
 *1
P0385
( DI−67 )Crankshaft Position Sensor
”B” Circuit Malfunction
Open or short in crankshaft position sensor circuit for NE2
signal
 Crankshaft position sensor for NE2 signal
 ECM
 *1
P0401
( DI−69 )Exhaust Gas Recirculation
Flow Insufficient Detected
EGR valve stuck closed
 Short in VSV circuit for EGR
 Open in EGR gas temp. sensor circuit
 EGR hose disconnected
 ECM
 *1
P0402
( DI−80 )Exhaust Gas Recirculation
Flow Excessive Detected
EGR valve stuck open
 EGR VSV open malfunction
 Open in VSV circuit for EGR
 Short in EGR gas temp. sensor circuit
 ECM
 *1
*1: MIL lights up
*2: MIL lights up or blinking
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FI4741
(fig.1)Acceptable
Resistance kΩ
− 20 0 20 40 60 80 100
( − 4) 32 68 104 140 176 212
30
20
10
53
2
1
0.5
0.3
0.2
0.1
Temp. °C (F °)
DI−26
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0110 Intake Air Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
The intake air temperature sensor is built into the air flow meter
and senses the intake air temperature.
A thermistor built in the sensor changes the resistance value
according to the intake air temperature. The lower the intake air
temperature, the greater the thermistor resistance value, and
the higher the intake air temperature, the lower the thermistor
resistance value (See fig.1).
The intake air temperature sensor is connected to the ECM
(See next page). The 5 V power source voltage in the ECM is
applied to the intake air temperature sensor from the terminal
THA via a resistor R.
That is, the resistor R and the intake air temperature sensor are
connected in series. When the resistance value of the intake air
temperature sensor changes in accordance with changes in the
intake air temperature, the potential at terminal THA also
changes. Based on this signal, the ECM increases the fuel in-
jection volume to improve driveability during cold engine opera-
tion.
If the ECM detects the DTC ”P0110”, it operates the fail safe
function in which the intake air temperature is assumed to be
20 °C (68 °F).
Intake Air Temp.
° C (° F)Resistance
(kΩ)Voltage
(V)
−20 (− 4)16.24.3
0 (32)5.93.4
20 (68)2.52.4
40 (104)1.11.4
60 (140)0.60.9
80 (176)0.30.5
100 (212)0.10.2
DTC No.DTC Detecting ConditionTrouble Area
P0110Open or short in intake air temp. sensor circuit
Open or short in intake air temp. sensor circuit
 Intake air temp. sensor
 ECM
HINT:
After confirming DTC P110 use the OBD II scan tool or TOYOTA hand −held tester to confirm the intake air
temp. from ”CURRENT DATA”.
Temp. DisplayedMalfunction
− 40° C (− 40°F)Open circuit
140°C (284°F) or moreShort circuit
DI5P1−02
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A00484
Intake Air Temp. Sensor
(Inside the mass air flow meter)
3
4 L−Y
BR−B 5V
ECM
E5
E5
THA
E1
E2
P22420
3
9 R
−
DIAGNOSTICS ENGINE
DI−27
1996 LAND CRUISER (RM451U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTCs P0110 (Intake Air Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction),
P0120 (Throttle/Pedal Position Sensor/Switch ”A” Circuit Malfunction)\
are output simultaneously, E2 (Sen-
sor Ground) may be open.
1 Connect the OBD II scan tool or TOYOTA hand −held tester, and read value of
intake air temperature.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the OBD II scan tool or TOYOTA hand−held tester to DLC3.
(c) Turn ignition switch ON and OBD II scan tool or TOYOTA hand−held tester main switch ON.
CHECK:
Read temp. value on the OBD II scan tool or TOYOTA hand −held tester.
OK:
Same as actual intake air temp.
HINT:
If there is open circuit, push OBD II scan tool or TOYOTA hand− held tester indicates − 40° C (− 40°F).
If there is short circuit, OBD II scan tool or TOYOTA handheld tester indicates 140° C (284°F) or more.
NG − 40° C (− 40 °F) ....Go to step 2.
140 °C (284°F) or more ....Go to step 4.
OK
Check for intermittent problems
(See page DI−3 ).
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