1996 TOYOTA LAND CRUISER engine misfire

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INTRODUCTION FOR ALL OF VEHICLES
IN−15
15
Author: Date:
1996 LAND CRUISER (RM451U)
3. FOR VEHICLES EQUIPPED WITH A CATALYTIC CONVERTER
CAUTION:
If large amount of unburned gasoline flows into the converter, it may overheat and create a fire haz-
ard. To prevent this, observe the following precautions and explain them to yo\
ur customer.
(a) Use only unleaded gasoline.
(b) Avoid prolonged idling.
Avoid running the engine at idle speed for more than 20 minutes.
(c) Avoid spark jump test. (1) Perform spark jump test only when absolutely necessary. Perform this test as rapidly as possible.
(2) While testing, never race the engine.
(d) Avoid prolonged engine compression measurement. Engine compression tests must be done as rapidly as possible.
(e) Do not run engine when fuel tank is nearly empty. This may cause the engine to misfire and create an extra load on the con\
verter.
(f) Avoid coasting with ignition turned off.
(g) Do not dispose of used catalyst along with parts contaminated with gasol\
ine or oil.
4. IF VEHICLE IS EQUIPPED WITH MOBILE COMMUNICATION SYSTEM
For vehicles with mobile communication systems such as two− way radios and cellular telephones, observe
the following precautions. (1) Install the antenna as far as possible away from the ECU and sensors of the vehicle’\
s electronic
system.
(2) Install the antenna feeder at least 20 cm (7.87 in.) away from the ECU and se\
nsors of the ve- hicle’s electronic systems. For details about ECU and sensors locations, refer\
to the section on
the applicable component.
(3) Avoid winding the antenna feeder together with other wiring as much as possible, and also avoid
running the antenna feeder parallel with other wire harnesses.
(4) Check that the antenna and feeder are correctly adjusted.
(5) Do not install powerful mobile communications system.
5. FOR USING OBD II SCAN TOOL OR TOYOTA HAND −HELD TESTER
CAUTION:
Observe the following items for safety reasons:
Before using the OBD II scan tool or TOYOTA hand −held tester, the OBD II scan tool’s instruc-
tion book or TOYOTA hand −held tester’s operator manual should be read thoroughly.
Be sure to route all cables securely when driving with the OBD II scan too\
l or TOYOTA hand −
held tester connected to the vehicle. (i.e. Keep cables away from feet,\
pedals, steering wheel
and shift lever.)
Two persons are required when test driving with the OBD II scan tool or TOYOTA hand −held
tester, one person to drive the vehicle and the other person to operate the OBD\
II scan tool or
TOYOTA hand−held tester.
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N09214
DI−4
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
The diagnosis system operates in normal mode
during normal vehicle use. It also has a check mode
for technicians to simulate malfunction symptoms
and troubleshoot. Most DTC use 2 trip detection
logic* to prevent erroneous detection, and ensure
thorough malfunction detection. By switching the
ECM to check mode when troubleshooting, the
technician can cause the MIL to light up for a mal-
function that is only detected once or momentarily
(TOYOTA hand−held tester only) (See step 2).
*2 trip detection logic:
When a logic malfunction is first detected, the mal-
function is temporarily stored in the ECM memory.
If the same malfunction is detected again during the
second drive test, this second detection causes the
MIL to light up.
The 2 trip repeats the same mode a 2nd time (How-
ever, the IG switch must be turned OFF between the
1st trip and 2nd trip.).
Freeze frame data:
Freeze frame data records the engine condition
when a misfire (DTC P0300 − P0306) or fuel trim
malfunction (DTC P0171, P0172) or other malfunc-
tion (first malfunction only), is detected.
Because freeze frame data records the engine
conditions (fuel system, calculator load, engine
coolant temperature, fuel trim, engine speed, ve-
hicle speed, etc.) when the malfunction is detected,
when troubleshooting it is useful for determining
whether the vehicle was running or stopped, the en-
gine warmed up or not, the air− fuel ratio lean or rich,
etc. at the time of the malfunction.
Priorities for troubleshooting:
If troubleshooting priorities for multiple DTCs are given in the
applicable diagnostic chart, these should be followed.
If no instructions are given troubleshoot DTCs according to the
following priorities. (1) DTC other than fuel trim malfunction (DTC P0171,
P0172), EGR (DTC P0401, P0402), and misfire
(DTC P0300 − P0306).
(2) Fuel trim malfunction (DTC P0171, P0172), and EGR (DTC P0401, P0402).
(3) Misfire (DTC P0300 − P0306).
(b) Check the DLC3. The vehicle’s ECM uses V.P.W. (V ariable Pulse Width) for
communication to comply with SAE J1850. The terminal
arrangement of DLC3 complies with SAE J1962 and
matches the V.P.W. format.
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DI−12
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
(b) TOYOTA Enhanced Signals.
TOYOTA hand−held tester displayMeasurement ItemNormal Condition*
MISFIRE RPMEngine RPM for first misfire rangeMisfire 0: 0 rpm
MISFIRE LOADEngine load for first misfire rangeMisfire 0: 0 g/r
INJECTORFuel injection time for cylinder No.1Idling: 2.0 − 3.5 ms
IAC STEP POSIntake Air Control Valve step position
Opening position step motor type IAC valveIdling: 10 − 50 step
STARTER SIGStarter SignalCranking: ON
CTP SWClosed Throttle Position Switch SignalThrottle Fully Closed: ON
A/C SIGA/C Switch SignalA/C ON: ON
PNP SWPark/Neutral Position Switch SignalP or N Position: ON
STOP LIGHT SWStop Light Switch SignalStop light switch ON: ON
FC IDLFuel Cut Idle: Fuel cut when throttle valve fully
closed, during decelerationFuel cut operating: ON
FC TAUFuel Cut TAU: Fuel cut during very light loadFuel cut operating: ON
CYL#1 − CYL#6Ratio of revolution variation for each cylinder
when variation is large0%
IGNITIONIgnition rate for all cylinders every 1,000 revolu-
tions0 − 3,000 rpm
EGRT GASEGR Gas Temp. Sensor V alueEGR not operating: Temp. between intake air
temp. and engine coolant temp.
EGR SYSTEMEGR System Operating ConditionIdling: OFF
FUEL PRES UP VSVFuel Pressure Up VSV SignalHigh temp. restarting: ON
FUEL PUMPFuel Pump SignalIdling: ON
TOTAL FT B1Total Fuel Trim Bank 1: Average value for fuel
trim system of bank 1Idling: 0.8 − 1.2 V
O2 LR B1, S1
Oxygen Sensor Lean Rich Bank 1, Sensor 1
Response time for oxygen sensor output to
switch from lean to rich
Idling after warmed up: 0 − 1,000 msec.
O2 RL B1, S1
Oxygen Sensor Rich Lean Bank 1, Sensor 1
Response time for oxygen sensor output to
switch from rich to lean
Idling after warmed up: 0 − 1,000 msec.
∗: If no conditions are specifically stated for ”ldling”, it means t\
he 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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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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S06273
E1
1
G−
2
BR
L
L G1
NE2
NE2−
12
E6
3
2
Distributor
Crankshaft Position Sensor G2
ECM
NE
4
1 L
L
G W
R
E6
E6
E6
E6
E6 11
10 4
56
DI−62
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DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
DTC P0335 Crankshaft Position Sensor ”A” Circuit Malfunction
CIRCUIT DESCRIPTION
The crankshaft position sensor (NE signal) consists of a signal plate and pick up coil. The NE\
signal plate
has 24 teeth and is built into the distributor. When the camshaft rotates, the protrusion on the signal plate
and the air gap on the pick up coil change, causing fluctuations in the magnetic field and generating an elec-
tromotive force in the pick up coil. The NE signal sensor generates 24 signals fo\
r every engine revolution.
The ECM detects the standard crankshaft angle based on the G1, G2 signals, \
detects the actual crankshaft
angle and the engine speed by the NE signals, and detects misfire by NE2 sign\
als.
DTC No.DTC Detecting ConditionTrouble Area
P0335
No crankshaft position sensor signal (NE signal) to ECM dur-
ing cranking.
(2 trip detection logic) Open or short in crankshaft position sensor circuit for NE
signal.
 Crankshaft position sensor for NE signal
 Starter
 ECM
No crankshaft position sensor signal (NE signal) to ECM with
engine speed 550 rpm or more (2 trip detection logic)
WIRING DIAGRAM
DI5PH−02
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P24663
2(−)
3
4 1
(+)
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DIAGNOSTICS ENGINE
DI−65
1996 LAND CRUISER (RM451U)
DTC P0340 Camshaft Position Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
The camshaft position sensors (G1 and G2 signals) consist of a signal pla\
te and a pick up coil. The G1, G2,
signal plates each have one tooth on the outer circumference and are built int\
o the distributor. When the
camshaft rotates, the protrusion on the signal plate and the air gap on the pick \
up coil change, causing fluc-
tuations in the magnetic field and generating an electromotive force in the pick \
up coil. The ECM detects the
standard crankshaft angle based on the G1, G2 signals, detects the actual cranks\
haft angle and engine
speed by the NE signals, and detects misfire by NE2 signals.
DTC No.DTC Detecting ConditionTrouble Area
P0340No camshaft position sensor signal (G signal) to ECM with
engine speed 550 rpm or more. Open or short in camshaft position sensor circuit
 Camshaft position sensor
 ECM
WIRING DIAGRAM
Refer to DTC P0335 (Crankshaft Position Sensor ”A” Circuit Malfunction) o\
n page DI−62 for the WIRING
DIAGRAM.
INSPECTION PROCEDURE
1 Check resistance of camshaft position sensor.
PREPARATION:
Disconnect camshaft position sensor connector.
CHECK:
Measure resistance between terminals 2, 3 and 4 of distributor
connector.
OK:
Resistance
Cold185 − 275 Ω
Hot240 − 325 Ω
”Cold” is from − 10°C (14°F) to 50°C (122°F) of engine coolant
temperature and "Hot" is from 50°C (122°F) to 100°C (212°\
F).
Reference: INSPECTION USING OSCILLOSCOPE
Refer to page DI−62 for Reference INSPECTION USING OS-
CILLOSCOPE.
NG Replace distributor housing assembly.
OK
DI5PI−02
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A00167P22894
P24664
−
DIAGNOSTICS ENGINE
DI−67
1996 LAND CRUISER (RM451U)
DTC P0385 Crankshaft Position Sensor ”B” Circuit
Malfunction
CIRCUIT DESCRIPTION
The crankshaft position sensor (NE2 signal) consists of a signal plate and a pick up coil. The NE2 signal plate
has 34 teeth and is mounted on the crankshaft. When the crankshaft rotates, the protrusion on the signal
plate and the air gap on the pick up coil change, causing fluctuations i\
n the magnetic field and generating
an electromotive force in the pick up coil. The NE2 signal sensor generate\
s 34 signals for every engine revo-
lution. The ECM detects the standard crankshaft angle based on G1, G2 signals d\
etects the actual crank-
shaft angle and the engine speed by NE signals, and detects misfire by NE2 si\
gnals.
DTC No.DTC Detecting ConditionTrouble Area
P0385
No crankshaft position sensor signal (NE 2 signal) to ECM
during cranking. (2 trip detection logic) Open or short in crankshaft position sensor for NE2 signals.
 Crankshaft position sensor for NE2 signal.
 ECM
No crankshaft position sensor signal (NE 2 signal) to ECM with
engine speed 550 rpm or more. (2trip detection logic)
WIRING DIAGRAM
Refer to DTC 0335 (Crankshaft Position Sensor ”A” Circuit Malfunction)\
on page DI−62 for WIRING DIA-
GRAM.
INSPECTION PROCEDURE
1 Check resistance of crankshaft position sensor for NE2 signal.
PREPARATION:
Disconnect crankshaft position sensor connector.
CHECK:
Measure resistance between terminals 1 and 2 of crankshaft
position sensor connector.
OK:
Resistance
Cold1630 − 2740 Ω
Hot2065 − 3225 Ω
”Cold” is from − 10°C (14°F) to 50°C (122°F) of engine coolant
temperature and "Hot" is from 50°C (122°F) to 100°C (212°F).
Reference: INSPECTION USING OSCILLOSCOPE
Refer to page DI−62 for Reference INSPECTION USING OS-
CILLOSCOPE.
NG Replace crankshaft position sensor.
OK
DI5PJ−02
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