TOYOTA CAMRY 1999 Service Repair Manual

A09289BE6653A09267
SPD
ON
(+) (±)
AT7809
4.5 ± 5.5 V
0
Turn the wheel
DI±70
± DIAGNOSTICSENGINE
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.
1 Check operation of speedometer.
CHECK:
Drive the vehicle and check if the operation of the speedmeter in the combination meter is normal.
HINT:
The vehicle speed sensor is operating normally if the speedometer display is normal.
NG Check speedometer circuit. See combination
meter troubleshooting (See Pub. No. RM654U,
page BE±2).
OK
2 Check voltage between terminal SPD of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Shift the shift lever to neutral.
(c) Jack up one of the front wheels.
(d) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal SPD of the ECM con-
nector 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.

± DIAGNOSTICSENGINE
DI±71
OK
Check and replace ECM (See page IN±29).

A01758
Throttle Valve
To Cylinder ECM SignalFrom
Air
Cleaner
Valve
IAC Valve
Intake Air
Chamber
A09420
Driver Side J/BEFI Relay
Engine Room R/B No.2 From
IG SwitchFrom
BatteryECM
E6 10
w
1
3 2 IAC Valve
B±Y
IG39
EB
B±Y
W±B 4
12 3 5 21EFI
B
37
1W 1KIGN
B±R
W±B
EC
RSD
7 12
2A
2J
2K
2FJ18
J/C
B B
DI±72
± DIAGNOSTICSENGINE
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTION
The rotary solenoid type IAC valve is located on the throttle
body and intake air bypassing the throttle valve is directed to
the IAC valve through a passage.
In this way the intake air volume bypassing the throttle valve is
regulated, controlling the engine speed.
The ECM operates only the IAC valve to perform idle±up and
provide feedback for the target idling speed.
DTC No.DTC Detecting ConditionTrouble Area
Open or short in IAC valve circuit
Open or short in IAC valve circuit

IAC valve is stuck or closed
P0505Idle speed continues to vary greatly from the target speed
(2 trip detection logic)

IAC valve is stuck or closed

Open or short in A/C switch circuit

Air induction system

ECM
WIRING DIAGRAM
DI3A3±03

± DIAGNOSTICSENGINE
DI±73
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.
TOYOTA hand±held tester:
1 Check idle speed.
PREPARATION:
(a) Warm up the engine to normal operating temperature.
(b) Switch off all the accessories.
(c) Switch off the A/C.
(d) Shift the transmission into the N or neutral position.
(e) Remove the fuse cover on the instrument panel.
(f) Connect the TOYOTA hand±held tester to the DLC3 on the vehicle and select the ACTIVE TEST
mode.
CHECK:
Check the difference of engine speed between the ones, less than 5 sec. and more than 5 sec. after switch-
ing the TE1 from OFF to ON by the TOYOTA hand±held tester.
OK:
Difference of engine speed: More than 100 rpm
OK Go to step 8.
NG
2 Check for IAC duty signal.
PREPARATION:
(a) Remove the fuse cover on the instrument panel.
(b) Connect the TOYOTA hand±held tester to the DLC3 on the vehicle.
(c) Turn the ignition switch ON and push the TOYOTA hand±held tester main switch ON.
CHECK:
Read the IAC duty ratio on the TOYOTA hand±held tester.
OK:
IAC duty ratio: 27 ± 47 %
OK Go to step 3.
NG
Check and replace ECM (See page IN±29).

BE6653A01553A01584
ON
2
(±)(+)
DI±74
± DIAGNOSTICSENGINE
3 Check operation of IAC valve (See page SF±22).
NG Go to step 5.
OK
4 Check blockage of IAC valve and passage to bypass throttle valve.
NG Repair or replace IAC valve and throttle body.
OK
Go to step 8.
5 Check voltage between terminal 2 of IAC valve connector and body ground.
PREPARATION:
(a) Disconnect the IAC valve connector.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal 2 of the IAC valve con-
nector and body ground.
OK:
Voltage: 9 ± 14 V
NG Check for open and short in harness and con-
nector between IAC valve and J/B.
OK
6 Check for open and short in harness and connector between terminal 3 of IAC
valve connector and body ground.
NG Repair or replace.

± DIAGNOSTICSENGINE
DI±75
OK
7 Check for open and short in harness and connector in RSD circuit.
NG Repair or replace.
OK
Replace IAC valve.
8 Check for A/C signal circuit (See Pub. No. RM654U, page AC±84).
NG Repair or replace.
OK
Check air induction system
(See page SF±1).
OBD II scan tool (excluding TOYOTA hand±held tester):
1 Check idle speed.
PREPARATION:
(a) Warm up the engine to normal operating temperature.
(b) Switch off all the accessories.
(c) Switch off the A/C.
(d) Shift the transmission into the N or neutral position.
(e) Remove the fuse cover on the instrument panel.
(f) Connect the OBD II scan tool to the DLC3 on the vehicle.
(g) Using SST, connect terminals TE1 and E1 of the DLC1.
SST 09843±18020
CHECK:
Check the difference of engine speed between the ones, less than 5 sec. and more than 5 sec. after connect-
ing terminals TE1 and E1 of the DLC1.
OK:
Difference of engine speed: More than 100 rpm

1 msec. /Division 5 V /Division
GND
A09303BE6653
A09648
ON
RSD
(±) (+)
DI±76
± DIAGNOSTICSENGINE
OK Go to step 8.
NG
2 Check for IAC duty signal.
PREPARATION:
(a) Warm up the engine normal operating temperature.
(b) Connect the oscilloscope between RSD of the ECM con-
nector and body ground.
CHECK:
Check if IAC duty signal is output.
OK:
HINT:
IAC duty ratio changes in response to engine operating condi-
tion.
OK Go to step 6.
NG
3 Check voltage between terminal RSD of ECM and body ground.
PREPARATION:
(a) Remove the lower center finish panel.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal RSD of the ECM con-
nector and body ground.
OK:
Voltage: 9 ± 14 V
OK Check and replace ECM (See page IN±29).

BE6653A01553A01584
ON
2
(±)(+)
± DIAGNOSTICSENGINE
DI±77
NG
4 Check voltage between terminal 2 of IAC valve connector and body ground.
PREPARATION:
(a) Disconnect the IAC valve connector.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal 2 of the IAC valve con-
nector and body ground.
OK:
Voltage: 9 14 V
NG Check for open and short in harness and con-
nector between IAC valve and J/B.
OK
5 Check for open and short in harness and connector in RSD circuit.
NG Repair or replace.
OK
Replace IAC valve.
6 Check operation of IAC valve (See page SF±25).
OK Go to step 8.
NG
7 Check for open in harness and connector between terminal 3 of IAC valve con-
nector and body ground.

DI±78
± DIAGNOSTICSENGINE
NG Repair or replace.
OK
Replace IAC valve.
8 Check blockage of IAC valve and the passage to bypass throttle valve.
NG Repair or replace IAC valve and throttle body.
OK
9 Check for A/C signal circuit (See Pub. No. RM654U, page AC±84).
NG Repair or replace.
OK
Check air induction system (See Pub. No.
RM654U, page SF±1).

A00364
Vehicle Speed
60 ± 120 km/h
(38 ± 75 mph)
Idling
IG SW OFF
3 ± 5 min.
Time
(1)(2)(4)
(3)
± DIAGNOSTICSENGINE
DI±79
DTC P1130 A/F Sensor Circuit Range/Performance Mal-
function (Bank 1 Sensor 1)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI±40.
DTC No.DTC Detecting ConditionTrouble Area
Voltage output* of A/F sensor remains at 4.5 V or more, during
engine running after engine is warmed up (2 trip detection log-
ic)
*: Output value changes at the inside of ECM only

Open or short in A/F sensor circuit

A/F sensor


Air induction system
P1130Voltage output* of A/F sensor does not change from 3.30 V,
during engine running after engine is warmed up (2 trip detec-
tion logic)
*: Output value changes at inside of ECM only

Air induction system

EGR system

Fuel pressure

Injector

ECM
Open or short in A/F sensor circuit (2 trip detection logic)
HINT:

After confirming DTC P1130, use the OBD II scan tool or TOYOTA hand-held tester to confirm voltage
output of the A/F sensor (AFS B1 S1/O2S B1 S1) from the CURRENT DATA.

The A/F sensor's output voltage and the short-term fuel trim value can be read using the OBD II scan
tool or TOYOTA hand-held tester.

The ECM controls the voltage of the AF+ and AF± terminals of the ECM to the fixed voltage. Therefore,
it is impossible to confirm the A/F sensor output voltage without OBD II scan tool or TOYOTA hand±
held tester.

OBD II scan tool (excluding TOYOTA hand-held tester) displays the one fifth of the A/F sensor output
voltage which is displayed on the TOYOTA hand-held tester.
WIRING DIAGRAM
Refer to DTC P0125 on page DI±40.
CONFIRMATION DRIVING PATTERN
DI01D±08