1999 TOYOTA CAMRY ignition

DI±106
± DIAGNOSTICSENGINE
8 Check for open and short in harness and connector between ignition switch and
ignition coil with igniter (See page IN±29).
NG Repair or replace harness or connector.
OK
Replace ignition coil with igniter.

A09282
BE6653Q06993A09270
Brake Pedal
Depressed ON
Brake Pedal
Released
STP
(±) (+)
± DIAGNOSTICSENGINE
DI±109
OK
2 Check STP signal.
When using TOYOTA hand±held tester:
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 the STP signal on the TOYOTA hand±held tester.
OK:
Brake PedalSTP Signal
DepressedON
ReleasedOFF
When not using TOYOTA hand±held tester:
PREPARATION:
Turn the ignition switch ON.
CHECK:
Check the voltage between terminal STP of the ECM connector
and body ground.
OK:
Brake PedalVoltage
Depressed7.5 ± 14 V
ReleasedBelow 1.5 V
OK Check for intermittent problems
(See page DI±3).
NG
3 Check harness and connector between ECM and stop light switch
(See page IN±29).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±29).

A09401
Engine Room J/B No.2
EFI11
B
Battery B±G11
2A E4ECM
F9BATT
2JB±Y
F118
FL Block
MAIN FL DI±110
± DIAGNOSTICSENGINE
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 circuit
Open in back up power source circuit

ECM
HINT:
If DTC P1600 appear, the ECM does not store another DTC.
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand±held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected. When troubleshooting it is useful for determining
whether the vehicle was running or stopped, the engine was warmed up or not, the air±fuel ratio was lean
or rich, etc. at the time of the malfunction.
DI01I±12

BE6653A03027A09272
START
STA
(±) (+)
DI±114
± DIAGNOSTICSENGINE
TOYOTA hand±held tester:
1 Connect TOYOTA hand±held tester, and check STA 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 the STA signal on the TOYOTA hand±held tester while the starter operates.
OK:
Ignition Switch PositionONSTART
STA signalOFFON
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 ECM and starter relay (Mark-
ing: ST) (See page IN±29).
NG Repair or replace harness or connector.
OK
Check and replace ECM (See page IN±29).
OBD II scan tool (excluding TOYOTA hand±held tester):
1 Check voltage between terminal STA of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal STA of the ECM connec-
tor and body ground, during the engine cranking.
OK:
Voltage: 6 V or more
OK Proceed to next circuit inspection shown on
problem symptoms table (See page DI±3).

A09403
ECM
+B 12
E4 B±Y J/C
B
J24 J23B
B±Y
Instrument
Panel J/B 22J 2K7
W±R EFI
Relay 1 3
52
2F4
W±B
2A 1
AM2
42L
B
FL
Block
MAIN
FL
B±GEngine
J/B No.2
5
1B
531K71W
IGN
1K
Room
W±R
IG
Switch
7 6
E6
BR
B±R
EC
E1
F11
F9EB
1
1
EFI
J20
J/C A
A
Battery
BR
16 B±R DI±116
± DIAGNOSTICSENGINE
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 (Marking: EFI) and supplying power to terminal +B of the ECM.
WIRING DIAGRAM
DI01L±07

A09291BE6653
A09273
ON
+B
E1
(±) (+)
± DIAGNOSTICSENGINE
DI±117
INSPECTION PROCEDURE
1 Check voltage between terminals +B and E1 of ECM connector.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals +B and E1 of the ECM
connector.
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±29).
NG Repair or replace harness or connector.
OK
3 Check EFI main relay (Marking: EFI) (See Pub. No. RM654U, page SF±40).
NG Replace EFI main relay.
OK
4 Check EFI fuse (See page DI±110, step 2).
NG Check for short in all harness and components
connected to EFI fuse.
OK

A00355
IGN Fuse
Instrument Panel J/B
DI±118
± DIAGNOSTICSENGINE
5 Check for open in harness and connector between EFI main relay (Marking: EFI)
and battery, and EFI main relay and ECM (See page IN±29).
NG Repair or replace harness or connector.
OK
6 Check IGN fuse.
PREPARATION:
Remove the IGN fuse from the instrument panel J/B.
CHECK:
Check the continuity of the IGN fuse.
OK:
Continuity
NG Check for short in all harness and components
connected to IGN fuse.
OK
7 Check ignition switch (See Pub. No. RM654U, page BE±14).
NG Replace ignition switch.
OK
Check for open in harness and connector between ignition switch and EFI main relay, and EFI
main relay and body ground (See page IN±29).

A09405
E5
IG2 L±W1
L±R
THR5 V ECM
E2
E59
BR
IG23
BR A/C Evaporator
Temp. Sensor
2 110
A09290BE6653
A09361
ON
E1 THR
(±) (+)
± DIAGNOSTICSENGINE
DI±121
A/C Evaporator Temp. Sensor Circuit
CIRCUIT DESCRIPTION
This sensor detects the temperature inside the cooling unit and sends the appropriate signals to the ECM.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 Check voltage between terminals THR and E2 of ECM connector.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminals THR and E1 of the
ECM connector at each temperature.
OK:
Voltage:
2.2 ± 2.6 V at 0°C (32 F)
1.4 ± 1.8 V at 15°C (59°F)
HINT:
As the temperature increases, the voltage decreases.
OK Check and replace ECM (See page IN±29).
DI01O±05