ignition TOYOTA T100 1996 Factory Manual Online

Downloaded from www.Manualslib.com manuals search engine S00876
W−RB−G
EFI
R/B No.2 22
W
8
EA1 IE1B−G
(M/T)17
B−G (A/T)B−G
(M/T)
E4 E42 1
(M/T)(A/T)ECM
BATT
Battery DI−11 2
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
DTC P1600 ECM BATT Malfunction
CIRCUIT DESCRIPTION
Battery positive voltage is supplied to terminal BATT of the ECM even when the ignition switch is OFF for
use by the DTC memory and air−fuel ratio adaptive control value memory, etc.
DTC No.DTC Detecting ConditionTrouble Area
P1600Open in back up power source circuitOpen in back up power source circuit
ECM
HINT:
If DTC P1600 appear, the ECM does not store another DTC.
WIRING DIAGRAM
DI0U4−03

Downloaded from www.Manualslib.com manuals search engine A00646
J/B No.1EA1
3
7
2IGN 1A
8
2
1
W
Battery
W−R
W−R 4 B−R
1C
17B−Y
IG
SwitchB−Y
IA3
W−R
4
AM2
3
2
R−L
W−R
R/B No.2EFI
22 2 225
B−W221 3
EFI
Relay
W−B
EA EB
EA1
9W−R
(M/T)
IE1
W−R
(M/T)
W−R (A/T)12 12
E4 E4
14 24
E7 E7 BR
(A/T) (M/T)
E1 +B
ECM
8
− DIAGNOSTICSENGINE (3RZ−FE)
DI−11 5
1996 TOYOTA T100 (RM449U)
ECM Power Source Circuit
CIRCUIT DESCRIPTION
When the ignition switch is turned ON, battery positive voltage is applied to the coil, closing the contacts of
the EFI main relay (Making: EFI) and supplying power to terminal +B of the ECM.
WIRING DIAGRAM
DI0U7−03

Downloaded from www.Manualslib.com manuals search engine BE6653
P24220
P24221
A00092
ON
E1 (−) +B (+)
E1 (−) +B (+) For M/T
For A/T
DI−11 6
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
1 Check voltage between terminals + B and E1 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 + B and E1 of ECM con-
nector.
OK:
Voltage: 9 − 14 V
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI−21).
NG
2 Check for open in harness and connector between terminal E1 of ECM and body
ground (See page IN−26).
NG Repair or replace harness or connector.
OK
3 Check EFI main relay (Marking: EFI) (See page MF−40).
NG Replace EFI main relay.
OK

Downloaded from www.Manualslib.com manuals search engine FI7106
IGN Fuse
J/B No.1
− DIAGNOSTICSENGINE (3RZ−FE)
DI−11 7
1996 TOYOTA T100 (RM449U)
4 Check EFI fuse (See page DI−11 4, step 2).
NG Check for short in all harness and components
connected to EFI fuse.
OK
5 Check for open in harness and connector between EFI main relay (Marking: EFI)
and battery, EFI main relay (Marking: EFI) and ECM (See page IN−26).
NG Repair or replace harness or connector.
OK
6 Check IGN fuse.
PREPARATION:
Remove the IGN fuse from the J/B No.1.
CHECK:
Check continuity of IGN fuse.
OK:
Continuity
NG Check for short in all the harness and compo-
nents connected to IGN fuse.
OK
7 Check ignition switch (See page BE−12).
NG Replace ignition switch.
OK
Check for open in harness and connector be-
tween IG switch and EFI main relay, EFI main
relay and body ground (See page IN−26).

Downloaded from www.Manualslib.com manuals search engine A00650
EFI Relay
EFI
AM2
AM1
ALT
BatteryIG Switch
IG
STIGN
Park/Neutral
Position Switch
(A/T)
Starter
Relay
Clutch
Start
Switch
(M/T)
StarterCircuit Opening Relay
L2
L1Fuel Pump
ECM
FC
Tr
STA
NE (STA Signal)
(NE Signal) From
Crankshaft
Position
Sensor DI−11 8
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
Fuel Pump Control Circuit
CIRCUIT DESCRIPTION
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 witches 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.
DI0U8−03

Downloaded from www.Manualslib.com manuals search engine A00770
ON
Fuel Return Hose
DI−120
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
INSPECTION PROCEDURE
TOYOTA hand−held tester:
1 Connect TOYOTA hand−held tester and check operation of fuel pump.
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.
(c) Use ”ACTIVE TEST” mode to operate the fuel pump.
CHECK:
Check for fuel pressure in the fuel return hose when it is pinched
off.
OK:
There is pressure in the fuel return hose.
HINT:
At this time, you will hear a fuel flowing noise.
OK Go to step 7.
NG
2 Check for ECM power source circuit (See page DI−11 5).
NG Repair or replace.
OK

Downloaded from www.Manualslib.com manuals search engine A00685
2 (+)
1 (+)
4 (−)
21
34
6
BE6653
P24224
P24225
A00095
ON
FC (+)
FC (+) For M/T
For A/T
− DIAGNOSTICSENGINE (3RZ−FE)
DI−121
1996 TOYOTA T100 (RM449U)
3 Check circuit opening relay.
PREPARATION:
Remove the circuit opening relay (See page MF−42).
CHECK:
(a) Apply battery voltage between terminals 2 and 4.
(b) Measure voltage between terminals 1 and 4.
OK:
Terminals 1 and 4Same 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 MF−50).
(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,
circuit opening relay and ECM.
OK

Downloaded from www.Manualslib.com manuals search engine A00688
ON
For M/T
For A/TFC (+)
FC (+)
Fuel Return Hose
DI−124
− DIAGNOSTICSENGINE (3RZ−FE)
1996 TOYOTA T100 (RM449U)
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 MF−50).
(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 fuel return hose when it is
pinched off.
OK:
There is pressure in the fuel return hose.
HINT:
At this time, you will hear a fuel return flowing noise.
OK Go to step 7.
NG
2 Check for ECM power source circuit (See page DI−11 5).
NG Repair or replace.
OK

Downloaded from www.Manualslib.com manuals search engine N09214
DLC3 DI−130
− DIAGNOSTICSENGINE (5VZ−FE)
1996 TOYOTA T100 (RM449U)
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 DTCs 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).
*2 trip detection logic: When a logic malfunction is
first detected, the malfunction is temporarily stored
in the ECM memory. If the same malfunction is de-
tected again during the 2nd drive test, this 2nd
detection causes the MIL to light up.
The 2 trip repeats the same mode a 2nd time. (How-
ever, the ignition switch must be turned OFF be-
tween the 1st trip and 2nd trip.)
Freeze frame data:
Freeze frame data records the engine condition
when a misfire (DTCs P0300 − P0306) or fuel trim
malfunction (DTCs P0171, P0172) or other mal-
function (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 DTC chart, these should be followed.
If no instructions are given troubleshoot DTCs according to the
following priorities.
(1) DTCs other than fuel trim malfunction (DTCs
P0171, P0172), EGR (DTCs P0401, P0402) and
misfire (DTCs P0300 − P0306).
(2) Fuel trim malfunction (DTCs P0171, P0172) and
EGR (DTCs P0401, P0402).
(3) Misfire (DTCs P0300 − P0306).
(b) Check the DLC3
The vehicle’s ECM uses V.P.W. (Variable 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.

Downloaded from www.Manualslib.com manuals search engine A00653
w/o Tachometer
w/ Tachometer
− DIAGNOSTICSENGINE (5VZ−FE)
DI−131
1996 TOYOTA T100 (RM449U) Terminal No.
Connection / Voltage or ResistanceCondition
2Bus  Line / Pulse generationDuring transmission
4Chassis Ground ↔ Body Ground / 1 Ω or lessAlways
5Signal Ground ↔ Body Ground / 1 Ω or lessAlways
16Battery Positive ↔ Body Ground / 9 − 14 VAlways
HINT:
If your display shows ”UNABLE TO CONNECT TO VEHICLE”
when you have connected the cable of the OBD II scan tool or
TOYOTA hand−held tester to DLC3, turned the ignition switch
ON and operated the scan tool, there is a problem on the ve-
hicle side or tool side.
If communication is normal when the tool is connected to
another vehicle, inspect DLC3 on the original vehicle.
If communication is still not possible when the tool is con-
nected to another vehicle, the problem is probably in the
tool itself, so consult the Service Department listed in the
tool’s instruction manual.
2. INSPECT DIAGNOSIS (Normal Mode)
(a) Check the MIL
(1) The MIL comes on when the ignition switch is turned
ON and the engine is not running.
HINT:
If the MIL does not light up, troubleshoot the combination meter
(See page BE−36).
(2) When the engine started, the MIL should go off. If
the lamp remains on, the diagnosis system has de-
tected a malfunction or abnormality in the system.
(b) Check the DTC.
NOTICE:
TOYOTA hand−held tester only: When the diagnosis sys-
tem is switched from normal mode to check mode, it erases
all DTCs and freezed frame data recorded in normal mode.
So before switching modes, always check the DTCs and
freezed frame data, and note them down.
(1) Prepare the OBD II scan tool (complying with SAE
J1978) or TOYOTA hand−held tester.
(2) Connect the OBD II scan tool or TOYOTA hand−
held tester to the DLC3 at the lower of the instru-
ment panel.
(3) Turn the ignition switch ON and push the OBD II
scan tool or TOYOTA hand−held tester switch ON.
(4) Use the OBD II scan tool or TOYOTA hand−held
tester to check the DTCs and freezed frame data,
note them down. (For operating instructions, see
the OBD II scan tool’s instruction book.)
(5) See page DI−129 to confirm the details of the
DTCs.