TOYOTA CAMRY 1999 Service Repair Manual

A07450
Ignition SwitchW±R B±RInstrument Panel J/B
FL
MAINFusible
Link
Block
BatteryJunction
ConnectorECM
B±R
W±R
BR
BR
W±B
B±Y
B
6
7
2 4
17
2 5
4
1 1B
AA F4 F6 E10E7
2F 2K 2J
2L
2AEFI EFI
RelayEngine Room
J/B+B
E1 17 16
AM2
EB EC
J28
3
1E72
MREL
E78IGSW
J27
1W
1B7
5 IGN
1K3
1K5
B+ B
B±Y
B±W
B±W
J35 J35
C
C
Junction
Connector
B±GJ22
Junction
Connector
± DIAGNOSTICSENGINE (1MZ±FE)
DI±369
604 Author: Date:
ECM Power Source Circuit
CIRCUIT INSPECTION
When the ignition switch is turned on, battery positive voltage is applied to terminal IGSW of the ECM and
the EFI main relay (Marking: EFI) control circuit in the ECM sends a signal to terminal MREL of the ECM
switching on the EFI main relay.
This signal causes current to flow to the coil, closing the contacts of the EFI, main relay and supplying power
to terminals +B of the ECM.
If the ignition switch is turned off, the ECM continues to switch on the EFI main relay for a maximum of 2
seconds for the initial setting of the IAC valve.
WIRING DIAGRAM
DI4DU±01

A02382
+B (+)
E1 (±)
A02951
IGSW (+)
DI±370
± DIAGNOSTICSENGINE (1MZ±FE)
605 Author: Date:
INSPECTION PROCEDURE
1 Check voltage between terminals +B and E1 or ECM connectors.
PREPARATION:
(a) Remove the glove compartment (See page SF±73).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals +B and E1 of the ECM
connectors.
OK:
Voltage: 9 ~ 14 V
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI±221).
NG
2 Check for open in harness and connector between terminals E1 of ECM and
body ground (See page IN±31).
NG Repair or replace harness or connector.
OK
3 Check voltage between terminal IGSW of ECM and body ground.
PREPARATION:
Turn the ignition switch ON.
CHECK:
Measure voltage between terminal IGSW of ECM connectors
and body ground.
OK:
Voltage: 9 ~ 14 V
OK Go to step 6.
NG

S04164
IGN Fuse
Instrument Panel J/B
± DIAGNOSTICSENGINE (1MZ±FE)
DI±371
606 Author: Date:
4 Check EFI fuse.
PREPARATION:
Remove IGN fuse from instrument panel J/B.
CHECK:
Check continuity of IGN fuse.
OK:
Continuity
NG Check for short in all the harness and compo-
nents connected to IGN fuse
(See attached wiring diagram).
OK
5 Check ignition switch (See page BE±13).
NG Replace ignition switch.
OK
Check and repair harness and connector be-
tween battery and ignition switch, and igni-
tion switch and ECM.

A02952
MREL (+)
DI±372
± DIAGNOSTICSENGINE (1MZ±FE)
607 Author: Date:
6 Check voltage between terminal MREL of ECM and body ground.
PREPARATION:
Turn the ignition switch ON.
CHECK:
Measure voltage between terminal MREL of the ECM
connectors and body ground.
OK:
Voltage: 9 ~ 14 V
NG Check and replace ECM (See page DI±197).
OK
7 Check EFI No.1 fuse of engine room J/B.
NG Check for short in all the harness and compo-
nents connected to EFI No.1 fuse
(See attached wiring diagram).
OK
8 Check EFI main relay (Marking: EFI) (See page SF±53).
NG Replace EFI main relay (Marking: EFI).
OK

± DIAGNOSTICSENGINE (1MZ±FE)
DI±373
608 Author: Date:
9 Check for open and short in harness and connector between terminal MREL of
ECM and body ground (See page IN±31).
NG Repair or harness or connector.
OK
Check and repair harness or connector be-
tween EFI No.1 fuse and battery
(See page IN±31).

A07151
Fuel Pump Circuit Opening Relay
EFI Main Relay
FC
Tr
MREL
IGSW
STA EFI
NEECM
Starter Starter Relay MAIN
Battery AM2IG Switch
(NE Signal) (STA Signal) Park/ Neutral Position Switch IGN
STARTER DI±374
± DIAGNOSTICSENGINE (1MZ±FE)
609 Author: Date:
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 and also current flows to terminal STA of ECM (STA signal).
When the STA signal and NE signal are input to the ECM, Tr is turned ON, current flows to coil of the circuit
opening relay, the relay switches on, power is supplied to the fuel pump 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.
DI4DV±01

A07451
ECM
E01 FC 3
E7
G±R
5EB1
G±R 1
1
1 1 15
3
2
CIR OPN Relay
Engine Room R/B
L±B
EB1
ID1L±B
A
A
5 4 10
7
W±B
W±BJ11
Junction
Connector
IG BL
StarterS2
B±R
EB
B±R 2D
2K 2F
9 5 4 2C 10
II2
10
Junction
Connector
J8 J7
C B(A/T)
(A/T) GR
(M/T) B±WPark/
Nutral
Position
Switch
6 5(A/T)
B±W(A/T)
B±WII2
11 11
ST Relay
B B
B EFI Relay23
15
2
13 5
2J 2K
W±BB±R W±B B±RB±W
7 8R1K
W±R
1J
43
1B
STARTER
5 5
1
2 B±W
W±B
2A
2B31
2L 4 AM27Instrument Panel J/B
Battery
B±GFL
MAIN F6
F4 1
Fusible
Link
BlockB B
EFI
MAINB+
MREL
8
E7
B±R
Fuel
Pump
1W 1K1
IGN
1
ST2
IG2
AM2Clutch
Start
Switch
L±BW±B
Junction
Connector
A
J40
Junction
Connector
1K 7
*B±O *1GR
(M/T)
*B±O *1GR
J35 J35C
*B±O *1GR
B±W
B±R
Junction
Connector J26
1
7
3
1K
*: TMMK made
*
1: TMC made
± DIAGNOSTICSENGINE (1MZ±FE)
DI±375
610 Author: Date:
WIRING DIAGRAM

A00244
ON
BE6653
P20186
DI±376
± DIAGNOSTICSENGINE (1MZ±FE)
611 Author: Date:
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 that pulsation damper screw rises up when fuel pump is
on by TOYOTA hand±held tester.
OK:
The pulsation damper screw rises up.
OK Check for starter signal circuit
( See page DI±384).
NG
2 Check for ECM power source circuit (See page DI±369).
NG Repair or replace.
OK
3 Check circuit opening relay (See page SF±54).
NG Replace circuit opening relay.
OK

A02064
ON
FC (+)
± DIAGNOSTICSENGINE (1MZ±FE)
DI±377
612 Author: Date:
4 Check voltage between terminal FC of ECM and body ground.
PREPARATION:
(a) Remove the glove compartment (See page SF±73).
(b) Turn ignition switch ON.
CHECK:
Measure voltage between terminal FC of ECM and body
ground.
OK:
Voltage 9 ± 14 V
NG Check for open in harness and connector be-
tween EFI main relay (Marking: EFI) and circuit
opening relay, circuit opening relay and ECM.
OK
5 Check fuel pump (See page SF±6).
NG Repair or replace fuel pump.
OK
6 Check for open in harness and connector between circuit opening relay
and fuel pump, and fuel pump and body ground
(See page IN±31).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±31).

A02042
ON
FC
DI±378
± DIAGNOSTICSENGINE (1MZ±FE)
613 Author: Date:
OBD II scan tool (excluding TOYOTA hand±held tester)
1 Check operation of fuel pump.
PREPARATION:
(a) Remove the glove compartment (See page SF±73).
(b) Turn the ignition switch ON.
CHECK:
(a) Connect between terminal FC of the ECM connector and
body ground.
(b) Check that pulsation damper screw rises up when con-
nect between terminal FC of the ECM and body ground.
OK:
The pulsation damper screw rises up.
OK Check for starter signal circuit
( See page DI±384).
NG
2 Check for ECM power source circuit (See page DI±369).
NG Repair or replace.
OK
3 Check circuit opening relay (See page SF±54).
NG Replace circuit opening relay.
OK