TOYOTA CAMRY 1999 Service Repair Manual

± DIAGNOSTICSENGINE (1MZ±FE)
DI±289
524 Author: Date:
3 Inspect sensor installation and teeth of crankshaft timing pulley.
NG Tighten the sensor.
Replace crankshaft timing pulley.
OK
Check and replace ECM
(See page IN±31).

DI±290
± DIAGNOSTICSENGINE (1MZ±FE)
525 Author: Date:
DTC P0340 Camshaft Position Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
Camshaft position sensor (G22 signal) consist of a signal plate and pickup coil.
The G22 signal plate has one tooth, on its outer circumference and is mounted on the left bank camshafts.
When the camshafts rotate, the protrusion on the signal plate and the air gap on the pickup coil change,
causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil.
The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34
signals for every engine revolution. The ECM detects the standard crankshaft angle based on the G22 signal
and the actual crankshaft angle and the engine speed by the NE signals.
DTC No.DTC Detecting ConditionTrouble Area
P0340
No camshaft position sensor signal to ECM during cranking
(2 trip detection logic)
Open or short in camshaft position sensor circuit

Camshaft position sensor
P0340No camshaft position sensor signal to ECM with engine speed
600 rpm or more

Camshaft osition sensor

Starter

ECM
WIRING DIAGRAM
Refer to DTC P0335 (Crankshaft Position Sensor ºAº Circuit Malfunction) on page DI±287 .
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 warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
1 Check resistance of camshaft position sensor (See page IG±1).
Reference INSPECTION USING OSCILLOSCOPE
Refer to DTC P0335 on page DI±287.
NG Replace camshaft position sensor.
OK
DI07V±06

± DIAGNOSTICSENGINE (1MZ±FE)
DI±291
526 Author: Date:
2 Check for open and short in harness and connector between ECM and camshaft
position sensor (See page IN±31).
NG Repair or replace harness or connector.
OK
3 Inspect sensor installation and tooth of left bank camshaft timing pulley.
NG Tighten the sensor.
Replace left bank camshaft timing pulley.
OK
Check and replace ECM (See page IN±31).

A00199
ECM
Mass Air Flow MeterVSV
for
EGR
EGR Valve
Position
Sensor
EGR Valve EGR Gas
Temp. Sensor
Crankshaft Position Sensor Engine Coolant
Temp. SensorIntake Air
Chamber Throttle ValveVacuum
Control
Valve
DI±292
± DIAGNOSTICSENGINE (1MZ±FE)
527 Author: Date:
DTC P0401 Exhaust Gas Recirculation Flow
Insufficient Detected (Ex CA Spec.)
CIRCUIT DESCRIPTION
The EGR system recirculates exhaust gas, which is controlled to the proper quantity to suit the driving condi-
tions, into the intake air mixture to slow down combustion, reduce the combustion temperature and reduce
NOx emissions.
The lift amount of EGR valve is controlled by the vacuum which is regulated by the Duty±VSV operated by
the ECM. The lift amount of EGR valve is detected by the EGR valve position sensor which is mounted on
the EGR valve and it provides feedback to the ECM to control the lift amount of EGR valve in response to
engine operating conditions.
Under the following conditions, EGR is cut to maintain driveability.

Before the engine is warmed up

During deceleration (throttle valve closed)

Light engine load (amount of intake air very small)

Engine speed over 4,000 rpm

Engine idling
DTC No.DTC Detecting ConditionTrouble Area
P0401
After engine is warmed up and run at 80 km/h (50 mph) for 3 to
5 min. EGR gas temperature sensor valve does not exceed
35°C (95°F) above ambient air temperature
(2 trip detection logic)

EGR valve (stuck closed)

Open or short in EGR gas temp. sensor circuit

EGR gas temp. sensor

Open in VSV circuit for EGR

VSV for EGR

Vacuum control valve

Vacuum hose disconnected or blocked

ECM
DI4DS±01

A07446
J20
Junction
Connector
EFI Relay
2K2J
2C
BB±YJ27 J28
W±B
EB
9B±Y Y±G
AA1218
13 1
2
G±Y
BRECM
EGR
E01
EGLS5 V
E2 32
VC
5 V
THG
E7
2
1W±GY
BR18
8
MREL
B+ BR
EGR Gas Temp. Sensor
E10 E10
22
E11 E10E11
Engine Room J/B
2A2
7 1
53
1 5
EFI
VSV
for EGR
B±Y
Junction
Connector
B
2
B±Y
J35
J35C
C Junction
ConnectorB±W
B±W
B±W
EGR Valve
Position Sensor
II3From
FL MAIN
S06906
Vehicle Speed
70 ~ 90 km/h
(43 ~ 56 mph)
Idling
IG SW OFF(1)(2)(3)
(4)(5)
Warmed up 3 ~ 5 min. 3 min. 3 ~ 5 min. 2 min.Time
± DIAGNOSTICSENGINE (1MZ±FE)
DI±293
528 Author: Date:
WIRING DIAGRAM
SYSTEM CHECK DRIVING PATTERN

DI±294
± DIAGNOSTICSENGINE (1MZ±FE)
529 Author: Date:
(1) Connect the OBD II scan tool or TOYOTA hand±held tester to the DLC3.
(2) Start and warm up the engine with all accessories switched OFF.
(3) Run the vehicle at 70 ~ 90 km/h (43 ~ 56 mph) for 3 min. or more.
(4) Idle the engine for about 2 min.
(5) Do steps (3) and (4) again.
(6) Stop at safe place and turn the ignition switch OFF.
(7) Do step (2) to (5) again.
(8) Check the READINESS TESTS mode on the OBD II scan tool or TOYOTA hand±held tester.
If COMPL is displayed and the MIL does not light up, the system is normal.
If INCMPL is displayed and the MIL does not light up, run the vehicle steps (2) to (6) from some times and
check it.
HINT:
INCMPL is displayed when either condition (a) or (b) exists.
(a) The system check is incomplete.
(b) There is a malfunction in the system.
If there is a malfunction in the system, the MIL light up after step (7) above is done.
(2trip detection logic)
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 warmed up or not, the air±fuel ratio lean or rich, etc.
at the time of the malfunction.
TOYOTA hand±held tester
1 Connect TOYOTA hand±held tester, and read value of EGR gas temperature.
PREPARATION:
(a) Connect the TOYOTA hand±held tester to the DLC3.
(b) Warm up the engine.
CHECK:
Read EGR gas temperature on TOYOTA hand±held tester during idling.
OK:
EGR gas temperature : 55C (415F) ~ 1505C (3025F) (Not immediately after driving)
HINT:
If there is an open circuit, TOYOTA hand±held tester indicates 3.15C (37.65F).
If there is an short circuit, TOYOTA hand±held tester indicates 159.35C (318.75F).
OK Go to step 4.
NG

A00305
ON
ON EGR Gas Temp.
Sensor
EGR Gas Temp.
SensorECM
ECM
5 V
5 V
E2
E2
1
2
1
2
THG
THG18 13
E10
E10
E10E10
13
18
± DIAGNOSTICSENGINE (1MZ±FE)
DI±295
530 Author: Date:
2 Check for open or short in harness or ECM.
For open circuit
PREPARATION:
(a) Disconnect the EGR gas temp. sensor connector.
(b) Connect the sensor wire harness terminals together.
(c) Turn the ignition switch ON.
CHECK:
Read EGR gas temperature on the TOYOTA hand±held tester.
OK:
EGR gas temperature : 159.35C (318.75F)
For short circuit
PREPARATION:
Disconnect the EGR gas temp. sensor connector.
CHECK:
Read EGR gas temperature on the TOYOTA hand±held tester.
OK:
EGR gas temp. : 3.15C (37.65F)
OK Confirm good connection at sensor.
If OK, check and replace EGR gas temp. sensor.
NG

A02048
ECM
THG E2ON
1
2E0
E107THG
E2 13
18 EGR Gas Temp. Sensor
5 V
A02043
ECM ON
EGR Gas Temp. Sensor
E10
5 V
THG
E2
DI±296
± DIAGNOSTICSENGINE (1MZ±FE)
531 Author: Date:
3 Check for open or short in harness or ECM.
For open circuit
PREPARATION:
(a) Remove the glove compartment (See page SF±73).
(b) Connect between terminals THG and E2 of the ECM con-
nectors.
HINT:
EGR gas temp. sensor connector is disconnected. Before
checking, do a visual check and contact pressure check for the
ECM connector (See page IN±31).
CHECK:
Read EGR gas temperature on the TOYOTA hand±held tester.
OK:
EGR gas temperature : 159.35C (318.75F)
For short circuit
PREPARATION:
(a) Remove the glove compartment (See page SF±73).
(b) Disconnect the E10 connector of ECM.
CHECK:
Read EGR gas temperature on the TOYOTA hand±held tester.
OK:
EGR gas temperature: 3.15C (37.65F)
OK Repair or replace harness.
NG
Confirm connection at ECM.
If OK, check and replace ECM.

A02507BE6653
A02839
ON
Air
E
GAir
G
FFE VSV is ON VSV is OFF
± DIAGNOSTICSENGINE (1MZ±FE)
DI±297
532 Author: Date:
4 Check connection and blockage of vacuum hose (See page EC±2).
NG Repair or replace vacuum hose.
OK
5 Check VSV for EGR.
PREPARATION:
Select the ACTIVE TEST mode on the TOYOTA hand±held
tester.
CHECK:
Check operation VSV, when it is operated by the TOYOTA
hand±held tester.
OK:
VSV is ON:
Air from pipe E is flowing out through pipe F and G.
VSV is OFF:
Air from pipe E is flowing out through pipe G.
OK Go to step 8.
NG
6 Check operation of VSV for EGR (See page SF±56).
NG Replace VSV for EGR.
OK
Check for open in harness and connector
between engine room J/B and ECM.

S05410
Vacuum
EGR Valve
DI±298
± DIAGNOSTICSENGINE (1MZ±FE)
533 Author: Date:
7 Check EGR system (See page EC±11).
NG Repair or replace.
OK
8 Check EGR valve.
PREPARATION:
(a) Disconnect the vacuum hose from EGR valve.
(b) Start the engine.
CHECK:
Check whether the engine stall when apply vacuum to EGR
valve.
OK:
Engine runs rough or stall.
NG Repair or replace EGR valve.
OK
9 Check vacuum control valve (See page EC±11).
NG Replace vacuum control valve.
OK
Check and replace ECM (See page IN±31).