Page 519 of 2062

Downloaded from www.Manualslib.com manuals search engine A01010
EFI
AM2
AM1
ALT
BatteryIG Switch
IG2
IG1
STIGNEFI Relay
Circuit Opening Relay
Clutch Start
Cancel Switch
(M/T)
L1 L2
ECM Fuel Pump
FC
Tr
STA
NE
Starter
Park/Neutral
Position Switch
(A/T)
Relay Starter
Start Clutch
Switch
(M/T)Crankshaft From
Position
Sensor(STA Signal)
(NE Signal)
− DIAGNOSTICSENGINE (5VZ−FE)
DI−255
1996 TOYOTA T100 (RM449U)
Fuel Pump Control Circuit
CIRCUIT DESCRIPTION
The fuel pump is switched on (low voltage at terminal FC) when STA is on or while the NE signal is input to
the ECM.
In the diagram below, when the engine is cranked, current flows from terminal ST of the ignition switch to
the starter relay coil, the starter relay switches on and current flows to coil L1 of the circuit opening relay.
Thus the circuit opening relay switches on, power is supplied to the fuel pump and the fuel pump operates.
When the STA signal and NE signal are input to the ECM, Tr is turned ON, current flows to coil L2 of the circuit
opening relay, the relay switches on and the fuel pump operates.
While the NE signal is generated (engine running), the ECM keeps Tr ON (circuit opening relay ON) and the
fuel pump also keeps operating.
DI0VC−01
Page 520 of 2062
Downloaded from www.Manualslib.com manuals search engine A00651
ECM
EFI AM2 ALT
Battery
IG Switch
Park/
Switch
StarterOpening Relay
Clutch
Start
Switch
E01 FC 4 14
E7 E5
(M/T)(A/T)
G−Y13
IE1 G−YL
1 4
6
Circuit
8
W−B
BJ1
W−B
IC
IC2 W−RW−R
EA19
EA
6
B−WB−R
Relay
(M/T)
3
B−O
WB−W
3
2
22
2 RelayEFI
2 22
51
2
22
2
22 5 R/B
1 2 2
2 3
1 W
W
B−YIA3
IGN
B (M/T)
B
Neutral
Position
(A/T)
Fuel
PumpW−BBJ1 BJ2
BJ2W−B(w/ ABS)
(w/o ABS)
11
(w/ ABS)
(w/o ABS)
10 16
Clutch
Start
Switch
(M/T)Cancel
No.2Starter
J/B No.1
B−R
B−WB−W
B−W B−W
B−W
B−O
B
B−R
W−B
W−RW
B−Y
W 2
2W−B
AM1
23
151 5
1 36 873 17 1113
IC
EB1
S1
EA1IA3
IA31C1A
1
IE1
IE1
B−Y
W−R
W−B
2
2 5 6 4
1
13A/T
DI−256
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
WIRING DIAGRAM
Page 522 of 2062
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2 (+)
1 (+)
4 (−)
1 2
34
6
BE6653
P24225
P24335A00128
ON
For M/T
For A/TFC (+)
FC (+)
DI−258
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
3 Check circuit opening relay.
PREPARATION:
Remove the circuit opening relay (See page SF−46).
CHECK:
(a) Apply battery voltage between terminals 2 and 4.
(b) Measure voltage between terminals 1 and 4.
OK:
Voltage: Same as battery
NG Replace circuit opening relay.
OK
4 Check voltage between terminal FC of ECM connector and body ground.
PREPARATION:
(a) Remove the right cowl side trim (See page SF−61).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminal FC of ECM connector and
body ground.
OK:
Voltage: 9 − 14 V
NG Check for open in harness and connector be-
tween EFI main relay and circuit opening relay,
and ECM (See page IN−26).
OK
Page 523 of 2062
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1 2
34
6
3 (+)
6 (−)1
2
− DIAGNOSTICSENGINE (5VZ−FE)
DI−259
1996 TOYOTA T100 (RM449U)
5 Check fuel pump (See page SF−5).
NG Repair or replace fuel pump.
OK
6 Check for open in harness and connector between circuit opening relay and fuel
pump, fuel pump and body ground (See page IN−26).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN−26).
7 Check circuit opening relay.
PREPARATION:
Remove the circuit opening relay (See page SF−46).
CHECK:
(a) Apply battery voltage between terminals 3 and 6.
(b) Check continuity between terminal 1 and 2.
OK:
Continuity
NG Replace circuit opening relay.
OK
Page 524 of 2062

Downloaded from www.Manualslib.com manuals search engine A00687
START3
BE6653P24337P24336
A00773A00789
ON
For M/T
For A/TFC (+)
FC (+)
Fuel Inlet Hose
DI−260
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
8 Check voltage between terminal 3 of circuit opening relay connector and body
ground.
CHECK:
Measure voltage between terminal 3 of circuit opening relay
connector and body ground when engine is cranked.
OK:
Voltage: 9 − 14 V
NG Check for starter signal circuit (See page
DI−248).
OK
Check for open in harness and connector be-
tween terminal 6 of circuit opening relay con-
nector and body ground (See page IN−26).
OBD II scan tool (excluding TOYOTA hand−held tester):
1 Check operation of fuel pump.
PREPARATION:
(a) Remove the right cowl side trim (See page SF−61).
(b) Turn the ignition switch ON.
CHECK:
(a) Connect between terminal FC of ECM connector and
body ground.
(b) Check for fuel pressure in the inlet hose when it is pinched
off.
OK:
There is pressure in the fuel inlet hose.
HINT:
At this time, you will hear a fuel flowing noise.
OK Go to step 7.
NG
Page 525 of 2062
Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSENGINE (5VZ−FE)
DI−261
1996 TOYOTA T100 (RM449U)
2 Check for ECM power source circuit (See page DI−251).
NG Repair or replace.
OK
3 Check circuit opening relay (See page DI−255, step 3).
NG Replace circuit opening relay.
OK
4 Check voltage between terminal FC of ECM connector and body ground (See
page DI−255, step 4).
NG Check for open in harness and connector be-
tween EFI main relay and circuit opening relay
and ECM (See page IN−26).
OK
5 Check fuel pump (See page SF−5).
NG Repair or replace fuel pump.
OK
Page 526 of 2062
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− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
6 Check for open in harness and connector between circuit opening relay and fuel
pump, fuel pump and body ground (See page IN−26).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN−26).
7 Check circuit opening relay (See page DI−255, step 7).
NG Replace circuit opening relay.
OK
8 Check voltage between terminal 3 of circuit opening relay connector and body
ground (See page DI−255, step 8).
NG Check for starter signal circuit (See page
DI−248).
OK
Check for open in harness and connector be-
tween terminal 6 of circuit opening relay con-
nector and body ground (See page IN−26).
Page 533 of 2062

Downloaded from www.Manualslib.com manuals search engine − DIAGNOSTICSAUTOMATIC TRANSMISSION
DI−269
1996 TOYOTA T100 (RM449U)
4. ROAD TEST
NOTICE:
Perform the test at normal operating ATF temperature 50 − 80°C (122 − 176°F).
(a) D position test
Shift into the D position and fully depress the accelerator pedal and and check the following points:
(1) Check up−shift operation.
1 → 2, 2 → 3 and 3 → O/D up−shift takes place, at the shift point shown in the automatic shift
schedule (See page SS−49).
HINT:
There is no O/D up−shift or lock−up when the coolant temperature is below 60°C (140°F).
Evaluation:
ProblemPossible cause
If there is no 1→2 up−shiftShift solenoid valve No.2 is stuck
1−2 shift valve is stuck
If there is no 2 →3 up−shiftShift solenoid valve No.1 is stuck
2−3 shift valve is stuck
If there is no 3 →O/D up−shift3−4 shift valve is stuck
If the shift point is defectiveThrottle valve, 1−2 shift valve, 2−3 shift valve, etc. are defective
If the lock up is defectiveShift solenoid valve SL is stuck
Lock−up relay valve is stuck
(2) Check for shift shock and slip.
Check for shock and slip at the 1 → 2, 2 → 3 and 3 → O/D up−shifts.
Evaluation:
ProblemPossible cause
If the shock is excessive
Line pressure is too high
Accumulator is defective
Check ball is defective
(3) Check for abnormal noises and vibration.
Run at the D position lock−up or O/D gear and check for abnormal noises and vibration.
HINT:
The check for the cause of abnormal noises and vibration must be done very thoroughly as it could also be
due to loss of balance in the differential torque converter clutch, etc.
(4) Check kick−down operation.
While running in the D position, 2nd, 3rd and O/D gears, check to see that the possible kick−down
vehicle speed limits for 2 → 1, 3 → 2 and O/D → 3 kick−downs conform to those indicated on
the automatic shift schedule (See page SS−49).
(5) Check abnormal shock and slip at kick−down.
(6) Check the lock−up mechanism.
Drive in D position, O/D gear, at a steady speed (lock−up ON).
Lightly depress the accelerator pedal and check that there is lock−up.
If there is a big jump in engine speed, there is no lock−up.
(b) 2 position test
Shift into the 2 position and fully depress the accelerator pedal and check the following points:
(1) Check up−shift operation.
Check to see that the 1 → 2 up−shift takes place and that the shift point conforms to the automatic
shift schedule (See page SS−49).