1996 TOYOTA T100 sensor

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (3RZ−FE)
DI−85
1996 TOYOTA T100 (RM449U)
2 Check for short in harness and connector between EGR gas temp. sensor and
ECM (See page IN−26).
NG Repair or replace harness or connector.
OK
3 Check VSV for EGR (See page MF−44).
OK Check EGR valve (See page EC−7).
NG
4 Check operation of VSV for EGR (See page MF−44).
NG Replace VSV for EGR.
OK
5 Check for open in harness and connector between R/B N0.2 and ECM (See page
IN−26).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN−26).

Downloaded from www.Manualslib.com manuals search engine FI7081
Waveform of Oxygen Sensor
before CatalystNormal CatalystWaveform of Oxygen Sensor
after Catalyst
P25762
Engine Speed
2500 − 3000 rpm
Idling
IG SW OFF
Warmed up3 minutesCheckTime (1)(3)
(4)
(2) DI−86
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0420 Catalyst System Efficiency Below Threshold
CIRCUIT DESCRIPTION
The ECM compares the waveform of the oxygen sensor located before the catalyst with the waveform of
the oxygen sensor located after the catalyst to determine whether or not catalyst performance has deterio-
rated.
Air−fuel ratio feedback compensation keeps the waveform of the oxygen sensor before the catalyst repeat-
edly changing back and forth from rich to lean.
If the catalyst is functioning normally, the waveform of the oxygen sensor after the catalyst switches back
and forth between rich and lean much more slowly than the waveform of the oxygen sensor before the cata-
lyst.
But when both waveforms change at a similar rate, it indicates that catalyst performance has deteriorated.


DTC No.DTC Detecting ConditionTrouble Area
P0420
After engine and catalyst are warmed up, and while vehicle is
driven within set vehicle and engine speed range, waveforms
of heated oxygen sensors (bank 1 sensor 1, 2) have same
amplitude (2 trip detection logic)
TWC (Three−way catalytic converter)
Heated oxygen sensor (bank 1 sensor 1, 2)
CONFIRMATION ENGINE RACING PATTERN
DI0TW−02

Downloaded from www.Manualslib.com manuals search engine FI6514
OX Signal Waveform (Oscilloscope)
1.0 V
0 V
200 msec. /Division
− DIAGNOSTICSENGINE (3RZ−FE)
DI−87
1996 TOYOTA T100 (RM449U)
(1) Connect the OBD ll scan tool or TOYOTA hand−held tester to the DLC3.
(2) Start engine and warm it up with all accessories switched OFF until the water temperature is stable.
(3) Race the engine at 2500 − 3000 rpm for about 3 min.
(4) After confirming that the waveform of the heated oxygen sensor, bank 1 sensor 1 (OX1), oscillate around
0.5 V during feedback to the ECM, check the waveform of the heated oxygen sensor bank 1 sensor 2 (OX2).
HINT:
If there is a malfunction in the system, the waveform of the
heated oxygen sensor bank 1 sensor 2 (OX2) is almost the
same as that of the heated oxygen sensor bank 1 sensor 1
(OX1) on the left.
There are some cases where, even though a malfunction
exists, the MIL may either light up or not light up.
INSPECTION PROCEDURE
1 Are there any other codes (besides DTC P0420) being output?
YES Go to relevant DTC chart.
NO
2 Check heated oxygen sensor (bank 1 sensor 1) (See page DI−47).
NG Repair or replace.
OK
3 Check heated oxygen sensor (bank 1 sensor 2) (See page DI−53).
NG Repair or replace.
OK
Replace TWC (three−way catalytic convert-
er) (See page EM−104).

Downloaded from www.Manualslib.com manuals search engine FI7112 FI7166
A00081
CableTo Speedometer Cable
T/M4−pulse
ECMMagnet Reed Switch
No.1 Vehicle Speed SensorCombination
Meter
P19617
ECM From Cruise
Control ECU
Combination Meter5 V
E1 SP1
E4 E4
(M/T)(A/T) G (M/T) G (M/T)
G (A/T)IE198
10
No.1
Vehicle
Speed
Sensor6
GG
C11
DI−92
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
This No.1 vehicle speed sensor is mounted in the combination meter. It contains a magnet which is rotated
by the speed meter cable.
Turning the reed switch ON and OFF 4 times for every revolution of the speedmeter.
It is then transmitted to the ECM. The ECM determines the vehicle speed based on the frequency of these
pluse signals.
DTC No.DTC Detecting ConditionTrouble Area
P0500
No vehicle speed sensor signal to ECM under conditions (a)
(2 trip detection logic)
(a) Vehicle is being drivenOpen or short in No.1 vehicle speed sensor circuit
No.1 vehicle speed sensor
ECM
Speedometer cable
WIRING DIAGRAM
DI0TY−05

Downloaded from www.Manualslib.com manuals search engine P24206
P24205 BE6653A00082
ON
For M/T
For A/TSP1 (+)
SP1 (+)
AT7809
4.5 − 5.5 V
0
Turn wheel
− DIAGNOSTICSENGINE (3RZ−FE)
DI−93
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
1 Check operation of speedometer.
CHECK:
Drive the vehicle and check if the operation of the speedometer in the combination meter is normal.
HINT:
The vehicle speed sensor is operating normally if the speedometer display is normal.
NG Check speedometer (See page BE−38).
OK
2 Check voltage between terminal SP1 of ECM connector and body ground.
PREPARATION:
(a) Remove the right cowl side trim (See page MF−50).
(b) Disconnect the cruise control ECU connector.
(c) Shift the shift lever to neutral.
(d) Jack up the rear wheels on one side.
(e) Turn the ignition switch ON.
CHECK:
Measure voltage between terminal SP1 of ECM connector and
body ground when the wheel is turned slowly.
OK:
Voltage is generated intermittently.
NG Check and repair harness and connector be-
tween combination meter and ECM.
OK
Check and replace ECM (See page IN−26).

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (3RZ−FE)
DI−97
1996 TOYOTA T100 (RM449U)
DTC P0510 Closed Throttle Position Switch Malfunction
CIRCUIT DESCRIPTION
Refer to DTC P0120 on page DI−39.
DTC No.DTC Detecting ConditionTrouble Area
P0510
Closed throttle position switch does not turn ON even once
when vehicle is driven
(2 trip detection logic)Open in closed throttle position switch circuit
Closed throttle position switch
ECM
HINT:
After confirming DTC P0510 use the TOYOTA hand−held tester to confirm the closed throttle position switch
signal from ”CURRENT DATA”.
Throttle ValveClosed Throttle Position Switch SignalMalfunction
Fully closedOFFOpen circuit
Fully openONShort circuit
WIRING DIAGRAM
Refer to DTC P0120 on page DI−39.
INSPECTION PROCEDURE
HINT:
If DTC P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) may be open.
TOYOTA hand−held tester:
1 Connect TOYOTA hand−held tester and read CTP switch signal.
PREPARATION:
(a) Connect the TOYOTA hand−held tester to the DLC3.
(b) Turn the ignition switch ON and push the TOYOTA hand−held tester main switch ON.
CHECK:
Read CTP switch signal on the TOYOTA hand−held tester.
RESULT:
Throttle ValveClosed Throttle Position Switch SignalMalfunction
Fully closedOFFOpen circuit: Go to step 2
Fully openONShort circuit: Go to step 4
DI0U0−03

Downloaded from www.Manualslib.com manuals search engine P19557BE6653
A00084
ON
ECM
1
2
3
411
11 1 0
12 11
99
Throttle Position
Sensor
E6
E6
(M/T)(A/T)5 V
VCC
VTA
IDL
E2B+
E1 E6 E6
E6 E6
E6 E6
DI−98
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
2 Check for open in harness or ECM.
PREPARATION:
(a) Connect the TOYOTA hand−held tester to the DLC3.
(b) Disconnect the throttle position sensor connector.
(c) Connect the sensor wire harness terminals between ter-
minals 3 and 4.
(d) Turn the ignition switch ON.
CHECK:
Read CTP switch signal on the TOYOTA hand−held tester.
OK:
CTP switch signal: ON
OK Confirm good connection at sensor.
If OK, replace throttle position sensor.
NG

Downloaded from www.Manualslib.com manuals search engine BE6653
P19556
P19711
P19687
A00085
ON
ECM
1
2
3
411
11 1 0
11
99
Throttle Position
Sensor
E6 E6
(M/T)(A/T)5 V
VCC
VTA
IDL
E2B+
E1
12
For M/T
For A/TE2
E2
IDL (+)
IDL (+)
E6 E6
E6 E6
E6 E6
− DIAGNOSTICSENGINE (3RZ−FE)
DI−99
1996 TOYOTA T100 (RM449U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove the right cowl side trim (See page MF−50).
(b) Connect between terminals IDL and E2 of the ECM con-
nector.
HINT:
Throttle position sensor connector is disconnected.
Before checking, do a visual check and contact pressure check
for the connector (See page IN−26).
(c) Turn the ignition switch ON.
CHECK:
Read CTP switch signal on the TOYOTA hand−held tester.
OK:
CTP switch signal: ON
OK Open in harness between ECM and throttle
position sensor, repair or replace harness.
NG
Confirm connection at ECM.
If OK, replace ECM.