1996 TOYOTA T100 engine

Downloaded from www.Manualslib.com manuals search engine BE6653
P23808
A00051
ON
1 (+)
P23809
Throttle Position
Sensor
1
2
4
− DIAGNOSTICSENGINE (3RZ−FE)
DI−41
1996 TOYOTA T100 (RM449U)
NG
2 Check voltage between terminal 1 of wire harness side connector and body
ground.
PREPARATION:
(a) Disconnect the throttle position sensor connector.
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals 1 of wire harness side con-
nector and body ground.
OK:
Voltage: 4.5 − 5.5 V
NG Go to step 5.
OK
3 Check throttle position sensor.
PREPARATION:
Disconnect the throttle position sensor connector.
CHECK:
Measure voltage between terminals 1, 2 and 4 of throttle posi-
tion sensor.
OK:
TerminalsThrottle valveResistance
1 − 4⎯2.5 − 5.9 kΩ
2 − 4Fully closed0.2 − 5.7 kΩ
2 − 4Fully open2.0 − 10.2 kΩ
NG Replace throttle position sensor.
OK

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P23810
P23811
A00052
For M/TON
For A/TVTA (+) E2 (−)
VTA (+) E2 (−)
BE6653
P23812
P23813A00028
For M/TON
For A/TVCC (+)
VCC (+) E2 (−) E2 (−)
DI−42
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
4 Check voltage between terminals VTA and E2 of ECM connector.
PREPARATION:
(a) Remove the right cowl side trim (See page MF−50).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals VTA and E2 of ECM con-
nector.
OK:
Throttle valveVoltage
Fully closed0.3 − 0.8 V
Fully open2.7 − 5.2 V
NG Check for open and short in harness and
connector between ECM and throttle position
sensor (VTA line) (See page IN−26).
OK
Check and replace ECM (See page IN−26).
5 Check voltage between terminals VCC and E2 of ECM connector.
PREPARATION:
(a) Remove the right cowl side trim (See page MF−50).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals VCC and E2 of ECM con-
nector.
OK:
Voltage: 4.5 − 5.5 V
NG Check and replace ECM (See page IN−26).
OK
Check for open in harness and connector be-
tween ECM and sensor (VCC line) (See page
IN−26).

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (3RZ−FE)
DI−43
1996 TOYOTA T100 (RM449U)
DTC P0121 Throttle/Pedal Position Sensor/Switch ”A”
Circuit Range/Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0120 on page DI−39.
DTC No.Detection ItemTrouble Area
P0121
After vehicle speed has been exceeded 30 km/h (19 mph)
even once, output value of throttle position sensor is out of
applicable range while vehicle speed between 30 km/h (19
mph and 0 km/h (0 mph)
Throttle position sensor
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0121) being output?
YES Go to relevant DTC chart.
NO
Replace throttle position sensor.
DI0TI−01

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A00027
Atmosphere
Flange
Platinum Electrode
Solid Electrolyte
(Zirconia Element)
Platinum Electrode
Heater
Coating (Ceramic)
Exhaust GasCoverIdeal Air−Fuel Mixture
Output Voltage
Richer − Air Fuel Ratio − Leaner DI−44
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0125 Insufficient Coolant Temp. for Closed Loop
Fuel Control
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three−way
catalytic converter is used, but for the most efficient use of the three−way catalytic converter, the air−fuel
ratio must be precisely controlled so that it is always close to the stoichiometric air−fuel ratio.
The oxygen sensor has the characteristic where by its output voltage changes suddenly in the vicinity of the
stoichiometric air−fuel ratio. This is used to detect the oxygen concentration in the exhaust gas and provide
feedback to the computer for control of the air−fuel ratio.
When the air−fuel ratio becomes LEAN, the oxygen concentration in the exhaust increases and the oxygen
sensor informs the ECM of the LEAN condition (small electromotive force: 0 V).
When the air−fuel ratio is RICHER than the stoichiometric air−fuel ratio the oxygen concentration in the ex-
haust gas is reduced and the oxygen sensor informs the ECM of the RICH condition (large electromotive
force: 1 V). The ECM judges by the electromotive force from the oxygen sensor whether the air−fuel ratio
is RICH or LEAN and controls the injection time accordingly. However, if malfunction of the oxygen sensor
causes output of abnormal electromotive force, the ECM is unable to perform accurate air−fuel ratio control.
The heated oxygen sensors include a heater which heats the zirconia element. The heater is controlled by
the ECM. When the intake air volume is low (the temp. of the exhaust gas is low) current flows to the heater
to heat the sensor for accurate oxygen concentration detection.
DTC No.DTC Detecting ConditionTrouble Area
P0125
After engine is warmed up, heated oxygen sensor output
does not indicate RICH even once when conditions (a), (b),
(c) and (d) continue for at least 1.5 min.:
(a) Engine speed: 1,500 rpm or more
(b) Vehicle speed: 40 ∼ 100 km/h (25 ∼ 62 mph)
(c) Closed throttle position switch: OFF
(d) 140 sec. or more after starting engine
Open or short in heated oxygen sensor (bank 1 sensor 1)
circuit
Heated oxygen sensor (bank 1 sensor 1)
HINT:
After confirming DTC P0125 use the OBD II scan tool or TOYOTA handheld tester to confirm voltage output
of heated oxygen sensor from "CURRENT DATA".
If voltage output of heated oxygen sensor is 0 V, heated oxygen sensor circuit may be open or short.
DI0TJ−02

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R/B No.2
B−W
22E6 E6
E6
E6
BRE1 E1
EB
2
2
22
From Battery From
IG Switch
EFI RelayW−R
EFI2
1 5 13EA1
IE1 W−RW−RW−R 9
9
W−R
Heated
Oxygen
Sensor
(Bank 1
Sensor 2)2
13
423
14Heated
Oxygen
Sensor
(Bank 1
Sensor 1)
P−G
E7 E7
E7 E7
E7 E7 R−G WECM
OX1
HT1
OX2
E1
HT2E03
E03 (M/T)(A/T)6
2
5
14
155
3
13
24
16 B
To Body Ground
− DIAGNOSTICSENGINE (3RZ−FE)
DI−45
1996 TOYOTA T100 (RM449U)
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Connect OBD II scan tool or TOYOTA hand−held tester and read value for volt-
age output of heated oxygen sensor (Bank 1 sensor 1).
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand−held tester to the DLC3.
(b) Warm up the engine to normal operating temp.
CHECK:
Read voltage output of heated oxygen sensor (bank 1 sensor 1) when engine is suddenly raced.
HINT:
Perform quick racing to 4,000 rpm 3 times using the accelerator pedal.
OK:
Heated oxygen sensor (bank 1 sensor 1) output a RICH signal (0.45 V or more) at least once
OK Check and replace ECM (See page IN−26).
NG

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− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
2 Check for open and short in harness and connector between ECM and heated
oxygen sensor (bank 1 sensor 1) (See page IN−26).
NG Repair or replace harness or connector.
OK
Replace heated oxygen sensor
(bank 1 sensor 1).

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Vehicle Speed
50 ∼ 65 km/h
(31 ∼ 40 mph)
Idling
IG SW OFF
1 ∼ 3 min. 1 min. Time
(1)(2)(3)(4)
(5)
− DIAGNOSTICSENGINE (3RZ−FE)
DI−47
1996 TOYOTA T100 (RM449U)
DTC P0130 Heated Oxygen Sensor Circuit Malfunction
(Bank 1 Sensor 1)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI−44.
DTC No.Detection ItemDTC Detecting ConditionTrouble AreaTrouble Area
P0130
Voltage output of heated oxygen sensor remains at 0.4 V or
more or 0.55 V or less, during idling after engine is warmed
up (2 trip detection logic)Heated oxygen sensor
Fuel trim malfunction
HINT:
Sensor 1 refers to the sensor closer to the engine body.
The heated oxygen sensor’s output voltage and the short−term fuel trim value can be read using the
OBD II scan tool or TOYOTA hand−held tester.
WIRING DIAGRAM
Refer to DTC P0125 on page DI−44.
CONFIRMATION DRIVING PATTERN
(1) Connect the TOYOTA hand−held tester to the DLC3.
(2) Switch the TOYOTA hand−held tester from normal mode to check mode (See page DI−13).
(3) Start the engine and warm it up with all the accessory switches OFF.
(4) Drive the vehicle at 50 − 65 km/h (31 − 40 mph) for 1 − 3 min. to warm up the heated oxygen sensor.
(5) Let the engine idle for 1 min.
HINT:
If a malfunction exists, the MIL will light up during step (5).
NOTICE:
If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.
If you do not have a TOYOTA hand−held tester, turn the ignition switch OFF after performing steps
(3) to (5), then perform steps (3) to (5) again.
DI0TK−02

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− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
1 Check for open and short in harness and connector between ECM and heated
oxygen sensor (See page IN−26).
NG Repair or replace harness or connector.
OK
2 Check for heated oxygen sensor data.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand−held tester to the DLC3.
(b) Warm up the engine to normal operating temp.
CHECK:
Read heated oxygen sensor output voltage and short−term fuel trim.
HINT:
Read the values for the same bank.
RESULT:
PatternHeated oxygen sensor output voltageShort−term fuel trim
1Lean condition (Changes at 0.55 V or less)Changes at about + 20 %
2Rich condition (Changes at 0.4 V or more)Changes at about − 20 %
3Except 1 and 2
1, 2 Check fuel trim system (See page DI−55).
3