1996 TOYOTA LAND CRUISER ignition

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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DI5OZ−02
A00152
Output Voltage
Power Transistor
B+
Thermistor
Platinum Hot Wire
A B
Thermistor Platinum Hot Wire
FI6929 P22263
DI−20
−
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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A00201
ON
BE6653
P24652
DI−22
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
1 Connect the OBD II scan tool or TOYOTA hand −held tester, and read value of
mass air flow rate.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the OBD II scan tool or TOYOTA hand−held tester to the DLC3.
(c) Turn ignition switch ON and OBD II scan tool or TOYOTA hand−held tester main switch ON.
(d) Start the engine.
CHECK:
Read mass air flow rate on the OBD II scan tool or TOYOTA hand−held tester.
RESULT:
Type IType II
Mass air flow rate (gm/sec.)Approx. 0 gm/sec.439.0 gm/sec. or more
Type I Go to step 2.
Type II Go to step 5.
2 Check voltage of mass air flow meter power source.
PREPARATION:
(a) Disconnect the mass air flow meter connector.
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminal 1 of mass air flow meter con-
nector and body ground.
OK:
Voltage: 9 − 14 V
NG Check for open in harness and connector between EFI main relay (Marking: EFI) and
mass air flow meter (See page IN−28 ).
OK
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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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A00154
ON
Intake Air
Temp. Sensor ECM
5V
E2 E1
3
4 3
9
E5
E5
BE6653
FI7055 A00154 THA
A00150
ON
Intake Air
Temp. Sensor ECM
5V
3
9 E2
E1
THA E2
THA
E5
E5
BE6653
FI7057
P24655
DI−28
−
DIAGNOSTICS ENGINE
1996 LAND CRUISER (RM451U)
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the mass air flow meter connector.
(b) Connect sensor wire harness terminals together.
(c) Turn ignition switch ON.
CHECK:
Read temp. value on the OBD II scan tool or TOYOTA hand −
held tester.
OK:
Temp. value: 140° C (284°F) or more
OK Confirm good connection at sensor. If OK, replace mass air flow meter.
NG
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove instrument panel speaker No.1 panel (See page SF−65 ).
(b) Connect between terminals THA and E2 of ECM connec-
tor.
HINT:
Mass air flow meter connector is disconnected.
Before checking, do a visual and contact pressure check for the
ECM connector (See page IN−28).
(c) Turn ignition switch ON.
CHECK:
Read temp. value on the OBD II scan tool or TOYOTA
hand −held tester.
OK:
Temp. value: 140° C (284°F) or more
OK Open in harness between terminals E2 or THA, repair or replace harness.
NG
Confirm good connection at ECM.
If OK, replace ECM (See page IN−28).
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A00151
ON
Intake Air
Temp. Sensor 3
4 ECM
3
9 5V
E2 E1
THA
E5
E5
BE6653
FI7054
A00155
ON
Intake Air
Temp. Sensor ECM
E5 connector 5V
E2 E1
THA
BE6653
FI7056
P19798
−
DIAGNOSTICS ENGINE
DI−29
1996 LAND CRUISER (RM451U)
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the mass air flow meter connector.
(b) Turn ignition switch ON.
CHECK:
Read temp. value on the OBD II scan tool or TOYOTA hand −
held tester.
OK:
Temp. value: − 40° C (− 40°F)
OK Replace mass air flow meter.
NG
5 Check for short in harness or ECM.
PREPARATION:
(a) Remove instrument panel speaker No.1 panel (See page SF−65 ).
(b) Disconnect the E5 connector of ECM.
HINT:
Mass air flow meter connector is disconnected.
(c) Turn ignition switch ON.
CHECK:
Read temp. value on the OBD II scan tool or TOYOTA hand −
held tester.
OK:
Temp. value: − 40°C (− 40 °F)
OK Repair or replace harness or connector (See page IN−28 ).
NG
Check and replace ECM (See page IN−28 ).
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A00156
ON
Engine Coolant
Temp. Sensor ECM
5V
4
9
2
1
E2
E1
THW
E5
E5
BE6653
FI7055
−
DIAGNOSTICS ENGINE
DI−31
1996 LAND CRUISER (RM451U)
INSPECTION PROCEDURE
HINT:
If DTC is 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
engine coolant temperature.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the OBD II scan tool or TOYOTA hand−held tester to the DLC3.
(c) Turn ignition switch ON and push the OBD II scan tool or TOYOTA hand−held tester main switch ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA hand −held tester.
OK:
Same as actual engine coolant temperature.
HINT:
If there is open circuit, OBD II scan tool or TOYOTA hand−held tester indicates − 40°C (− 40 °F).
If there is short circuit, OBD II scan tool or T OYOTA hand−held 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 ).
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the engine coolant temp. sensor connector.
(b) Connect sensor wire harness terminals together.
(c) Turn ignition switch ON.
CHECK:
Read temp. value on the OBD II scan tool or TOYOTA hand −
held tester.
OK:
Temp. value: 140° C (284°F) or more
OK Confirm good connection at sensor. If OK, replace engine coolant temp. sensor.
NG
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