V08423
Knock Sensor 1
GR ECM
KNK E1
12
E6
WIRING DIAGRAM
Wiring Diagram
This shows a wiring diagram of the circuit.
Use this diagram together with ELECTRICAL
WIRING DIAGRAM to thoroughly understand the
circuit.
Wire colors are indicated by an alphabetical code.
B = Black, L = Blue, R = Red, BR = Brown,
LG = Light Green, V = Violet, G = Green,
O = Orange, W = White, GR = Gray, P = Pink,
Y = Yellow, SB = Sky Blue
The first letter indicates the basic wire color and
the second letter indicates the color of the stripe.
DTC P0325Knock Sensor 1 Circuit Malfunction
CIRCUIT DESCRIPTION
Knock sensor is fitted to the cylinder block to detect engine knocking. This sensor c\
ontains a piezoelectric element which
generates a voltage when it becomes deformed, which occurs when the cyli\
nder block vibrates due to knocking. If engine
knocking occurs, ignition timing is retarded to suppress it.
DTC No. DTC Detection Condition Trouble Area
P0325 No knock sensor 1 signal to ECM with engine speed,
1,200 rpm or more. Open or short in knock sensor1 circuit
Knock sensor 1 (looseness)
ECM
If the ECM detects the above diagnosis conditions, it operates the fall sa\
fe function in which the corrective retard angle
value is set to the maximum value.
Diagnostic Trouble Code No. and Detection Item
Circuit Description
The major role and operation, etc. of the circuit
and its component parts are explained.
Indicates the diagnostic trouble code, diagnostic
trouble code set parameter and suspect area of
the problem.
IN−26
−
INTRODUCTION HOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
1996 LAND CRUISER (RM451U)
6. CIRCUIT INSPECTION
How to read and use each page is shown below.
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INTRODUCTION TERMS
IN−37
37
Author: Date:
1996 LAND CRUISER (RM451U)
TC
Turbocharger
TCCSTOYOTA
Computer− Controlled System
TCVTiming Control V alve
TDCTop Dead Center
TEMP.Temperature
TEMSTOYOTA Electronic Modulated Suspension
TISTotal Information System For Vehicle Development
T/MTransmission
TMCTOYOTA Motor Corporation
TMMKTOYOTA Motor Manufacturing Kentucky, Inc.
TRACTraction Control System
TURBOTurbocharge
U/DUnderdrive
U/SUndersize
VCVVacuum Control V alve
VENTVentilator
VINVehicle Identification Number
VPSVariable Power Steering
VSCVehicle Skid Control
VSVVacuum Switching Valve
VTVVacuum Transmitting V alve
w/With
WGNWagon
W/HWire Harness
w/oWithout
1stFirst
2ndSecond
2WDTwo Wheel Drive Vehicle (4x2)
4WDFour Wheel Drive Vehicle (4x4)
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DIAGNOSTICS ENGINE
DI−7
1996 LAND CRUISER (RM451U)
(10) After checking the DTC, inspect the applicable cir-
cuit.
(b) Clear the DTC.
The following actions will erase the DTCs and freezed
frame data.
(1) Operating the OBD II scan tool (complying with SAE
J1978) or TOYOTA hand−held tester to erase the
codes. (See the OBD II scan tool’ s instruction book
for operating instructions.)
(2) Disconnecting the battery terminals or EFI fuse.
NOTICE:
If the TOYOTA hand −held tester switches the ECM from
normal mode to check mode or vice −versa, or if the igni-
tion switch is turned from ON to ACC or LOCK during check
mode, the DTCs and freezed frame data will be erased.
4. FAIL−SAFE CHART
If any of the following codes is recorded, the ECM enters fail −safe mode.
DTC No.Fail−Safe OperationFail− Safe Deactivation Conditions
P0100Ignition timing fixed at 5 ° BTDC
Injection method fixed at simultaneous injectionReturned to normal condition
P0110Intake air temp. is fixed at 20° C (68°F)Returned to normal condition
P0115Engine coolant temp. is fixed at 80 °(176°F)Returned to normal condition
P0120VTA is fixed at 0°
The following condition must be repeated at least 2 times
consecutively
When closed throttle position switch is ON:
0.1 V VTA 0.95 V
P0135
P0141The heater circuit in witch an abnormality is detected is
turned offIgnition switch OFF
P0325
P0330Max. timing retardationIgnition switch OFF
P1300Fuel cutIGF signal is detected for 6 consective ignitions
P1605Max. timing retardationReturned to normal condition
5. CHECK FOR INTERMITTENT PROBLEMS
TOYOTA hand−held tester only:
By putting the vehicle’s ECM in check mode, 1 trip detection logic is possible instead of 2 trip detection logic
and sensitivity to detect open circuits is increased. This makes it easier \
to detect intermittent problems.
(1) Clear the DTC (See step 2).
(2) Set the check mode (See step 3).
(3) Perform a simulation test (See page IN−18).
(4) Check the connector and terminal (See page IN−28).
(5) Handle the connector (See page IN−28).
(6) Visual check and contact pressure (See page IN−28).
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A00149
DLC1
E1
TE1 SST
P09137
P23430
−
DIAGNOSTICS ENGINE
DI−9
1996 LAND CRUISER (RM451U)
OK
5 Check idle speed.
PREPARATION:
(a) Warm up engine to normal operating temperature.
(b) Switch off all accessories.
(c) Switch off air conditioning.
(d) Shift transmission into ”N” position.
(e) Connect the OBD II scan tool or TOYOTA hand−held tester to DLC3 on the vehicle.
CHECK:
Use CURRENT DATA to check the idle speed.
OK:
Idle speed: 650 ± 50 rpm
NG Proceed to matrix chart of problem symptomson page DI−19.
OK
6 Check ignition timing.
PREPARATION:
(a) Warm up engine to normal operating temperature.
(b) Shift transmission into ”N” position.
(c) Keep the engine speed at idle.
(d) Using SST, connect terminals TE1 and E1 of DLC1. SST 09843−18020
(e) Connect a timing light probe to a high −tension cord.
CHECK:
Check ignition timing.
OK:
Ignition timing: 3 ° BTDC at idle
NG Proceed to page IG−1 and continue to trouble-
shoot.
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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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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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DI5OZ−02
A00152
Output Voltage
Power Transistor
B+
Thermistor
Platinum Hot Wire
A B
Thermistor Platinum Hot Wire
FI6929 P22263
DI−20
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DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
CIRCUIT INSPECTION
DTC P0100 Mass Air Flow Circuit Malfunction
CIRCUIT DESCRIPTION
The mass air flow meter uses a platinum hot wire. The hot wire air flow met\
er consists of a platinum hot wire,
thermistor and a control circuit installed in a plastic housing. The hot wire air f\
low meter works on the principle
that the hot wire and thermistor located in the intake air bypass of the hou\
sing detect any changes in the
intake air temperature.
The hot wire is maintained at the set temperature by controlling the curren\
t flow through the hot wire. This
current flow is then measured as the output voltage of the air flow mete\
r.
The circuit is constructed so that the platinum hot wire and thermistor pro\
vide a bridge circuit, with the power
transistor controlled so that the potential of ”A” and ”B” remains equ\
al to maintain the set temperature.
DTC No.DTC Detecting ConditionTrouble Area
P0100Open or short in mass air flow meter circuit with engine
speed 4,000 rpm or less. Open or short in mass air flow meter circuit
Mass air flow meter
ECM
If the ECM detects DTC” P0100” it operates the fail safe function, k\
eeping the ignition timing and injection
volume constant and marking it possible to drive the vehicle.
HINT:
After confirming DTC P0100 use the OBD II scan tool or TOYOTA hand −held tester to confirm the mass air
flow ratio from ”CURRENT DATA”.
Mass Air Flow Value (gm/sec.)Malfunction
Approx. 0Mass air flow meter power source open
VG circuit open or short
439.0 or moreE21 circuit open
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DI−54
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0300 Random/Multiple Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
DTC P0305 Cylinder 5 Misfire Detected
DTC P0306 Cylinder 6 Misfire Detected
CIRCUIT DESCRIPTION
Misfire: The ECM uses the crankshaft position sensor and camshaft position senso\
r to monitor changes in
the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed change rate indicates that misfire has occurred.
When the misfire rate equals or exceeds the count indicating that the engine condition has deteriorat\
ed, the
MIL lights up.
If the misfire rate is high enough and the driving conditions will cause catalyst overheating, the MIL blinks
when misfiring occurs.
DTC No.DTC Detecting ConditionTrouble Area
P0300Misfiring of random cylinders is detected during the any partic-
ular 200 or 1,000 revolutions Ignition system
Injector
Fuel line pressure
EGR
Compression pressure
Valve clearance not to specification
Valve timing
Mass air flow meter
Engine coolant temp. sensor
P0301
P0302
P0303
P0304
P0305
P0306For any particular 200 revolutions of the engine, misfiring is
detected which can cause catalyst overheating
(This causes MIL to blink)
For any particular 1,000 revolutions of the engine, misfiring is
detected which causes a deterioration in emission
(2 trip detection logic)
HINT:
When the 2 or more codes for a misfiring cylinder are recorded repeatedly bu\
t no random misfire code is
recorded, it indicates that the misfires were detected and recorded at d\
ifferent times.
DI5PF−02
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