TOYOTA CAMRY 1999 Service Repair Manual

A00406
KNK Signal Waveform
0.5 V/
Division
0V
0V5 msec./Division
100
sec./Division 0.5 V/
Division
± DIAGNOSTICSENGINE (5S±FE)
DI±99
334 Author: Date:
4 Does malfunction disappear when good knock sensor 1 is installed?
YES Replace knock sensor 1.
NO
Check and replace ECM (See page IN±31).
Reference: INSPECTION USING OSCILLOSCOPE
With the engine racing (4,000 rpm), measure between terminal
KNK of the ECM connector and body ground.
HINT:
The correct waveforms are as shown.
Spread the time on the horizontal axis, and confirm that period
of the wave is 132 msec.
(Normal mode vibration frequency of knock sensor:
7.6 kHz)
HINT:
If normal mode vibration frequency is not 7.6 kHz the sensor is
malfunctioning.

A03599
ECM
G+
NE+
NE±
E1 E9
E9
E95
4
17 B±W
L
B±R
L BR Camshaft Position Sensor
Crankshaft Position Sensor1
2
1
2
*1: w/o Immobiliser
*2: w/ Immobiliser(*1) (*2)
E10
E10
E1012 11
6
(*1) (*2)(*1) (*2)
B±R DI±100
± DIAGNOSTICSENGINE (5S±FE)
335 Author: Date:
DTC P0335 Crankshaft Position Sensor ºAº Circuit
Malfunction
CIRCUIT DESCRIPTION
Crankshaft position sensor (NE signal) consist of a signal plate and pickup coil.
The NE signal plate has 34 teeth and is mounted on the crankshaft. The NE signal sensor generates 34
signals of every engine revolution. The ECM detects the standard crankshaft angle based on the G signals,
and the actual crankshaft angle the engine speed by the NE signals.
DTC No.DTC Detecting ConditionTrouble Area
No crankshaft position sensor signal to ECM during cranking
(2 trip detection logic)
Open or short in crankshaft position sensor circuit.
C k h ft itiP0335No crankshaft position sensor signal to ECM with engine
speed 600 rpm or more
(2 trip detection logic)
Crankshaft position sensor

Starter

ECM
WIRING DIAGRAM
DI013±10

A01991A01992A02359
G and NE Signal Waveforms
5 V/
Division
5 V/
Division G
NE
G
NE20 msec./Division (Idling)
10 msec./Division (Idling)
± DIAGNOSTICSENGINE (5S±FE)
DI±101
336 Author: Date:
INSPECTION PROCEDURE
HINT:

Perform troubleshooting of DTC 335 first. If notrouble is found, troubleshoot the following mechanical
system.

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 crankshaft position sensor (See page IG±1).
Reference: INSPECTION USING OSCILLOSCOPE
During cranking or idling, check between terminals G and G±,
NE and NE± of the ECM
HINT:
The correct waveforms are as shown.
NG Replace crankshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and
crankshaft position sensor (See page IN±31).
NG Repair or replace harness or connector.
OK

DI±102
± DIAGNOSTICSENGINE (5S±FE)
337 Author: Date:
3 Inspect sensor installation and teeth of crankshaft timing pulley
(See pages IG±10 and EM±15).
NG Tighten the sensor. Replace crankshaft timing
pulley.
OK
Check and replace ECM (See page IN±31).

± DIAGNOSTICSENGINE (5S±FE)
DI±103
338 Author: Date:
DTC P0340 Camshaft Position Sensor Circuit
Malfunction
CIRCUIT DESCRIPTION
Camshaft position sensor (G signal) consist of signal plate and pickup coil.
The G signal plate has one tooth on its outer circumference and is mounted on the exhaust camshaft.
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 G signals
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
Di t ib tP0340No camshaft position sensor signal to ECM with engine speed
600 rpm or more
Distributor

Starter

ECM
WIRING DIAGRAM
Refer to DTC P0335 (Crankshaft Position Sensor ºAº Circuit Malfunction) on page DI±100.
DI014±09

DI±104
± DIAGNOSTICSENGINE (5S±FE)
339 Author: Date:
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 (signal generator)
(See page IG±1).
Reference: INSPECTION USING OSCILLOSCOPE
Refer to DTC P0335 (Crankshaft Position Sensor ºAº Circuit Malfunction) on page DI±100.
NG Replace camshaft position sensor.
OK
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 camshaft timing pulley
(See pages IG±9 and EM±17).
NG Tighten the sensor. Replace camshaft timing
pulley.
OK
Check and replace ECM (See page IN±31).

P25430
ECM
Throttle Body
EGR
Vacuum
Modulator EGR Valve
VSV
Exhaust Gas Throttle
Valve
u
± DIAGNOSTICSENGINE (5S±FE)
DI±105
340 Author: Date:
DTC P0401 Exhaust Gas Recirculation Flow Insufficient
Detected
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 amount of EGR is regulated by the EGR vacuum modulator according to the engine
load.
If even one of the following conditions is fulfilled, the VSV is
turned ON by a signal from the ECM.
This results in atmospheric air acting on the EGR valve, closing
the EGR valve and shutting off the exhaust gas (EGR cut±off).
Under the following conditions, EGR is cut to maintain driveabil-
ity.

Before engine is warmed up.

During deceleration (throttle valve closed).

Light engine load (amount of intake air very small).

Engine idling.

Engine speed over 4,400 rpm.

High engine load (amount of intake air very large).
DTC No.DTC Detecting ConditionTrouble Area
P0401
After engine is warmed up, intake manifold absolute pressure
is larger than value calculated by ECM while EGR system is
ON
(2 trip detection logic)

EGR valve stuck closed

Open or short in VSV circuit for EGR

Vacuum or EGR hose disconnected

Manifold absolute pressure sensor

VSV for EGR open or close malfunction

ECM
DI015±05

A07551
ECM
J19
J/C
7 From
Battery
B
213
EFI Relay VSV
for EGR
21P-B23
E9EGR
E01
2K2
2J EFI
II4
Engine Room J/B No.2 1B
B-W 9
B-Y
B
2AB-Y
II3
EB
W-B
2F4
6
B-W B-YE815
MREL E107 (*1) (*2)
(*2)
*1: w/o Immobiliser
*2: w/ Immobiliser(*2) (*2)
5B-Y
(*1)From
Ignition SW DI±106
± DIAGNOSTICSENGINE (5S±FE)
341 Author: Date:
WIRING DIAGRAM

P20769
Vehicle Speed
60 ~ 80 km/h
(38 ~ 50 mph)
Idling
IG SW OFF
(1)(2)
Warm up
3 ~ 5 min.2 min.
3 ~ 5 min.Time (3)
(4)
(5)(6)
(7)
2 min.
± DIAGNOSTICSENGINE (5S±FE)
DI±107
342 Author: Date:
SYSTEM CHECK DRIVING PATTERN
(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 60 ~ 80 km/h (38 ~ 50 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 steps (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 again 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 will light up after steps (2) to (5) above are done.
(2 trip detection logic)
INSPECTION PROCEDURE
HINT:

If DTC P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction), P0106 (Manifold
Absolute Pressure/Barometric Pressure Circuit Range/Performance Problem) and P0401 (Exhaust
Gas Recirculation Flow Insufficient Detected) are output simultaneously, perform troubleshooting of
DTC P0105 first.

If DTC P0401 (Exhaust Gas Recirculation Flow Insufficient Detected) and P0402 (Exhaust Gas Recir-
culation Flow Excessive Detected) are output simultaneously, perform troubleshooting of DTC P0402
first.

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.

A00407
Air
Air FilterAir
E
System: OFFSystem: ON GG E
DI±108
± DIAGNOSTICSENGINE (5S±FE)
343 Author: Date:
TOYOTA hand±held tester:
1 Check connection of the vacuum hose and EGR hose (See page EC±12).
NG Repair or replace.
OK
2 Check VSV for EGR.
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) Select the ACTIVE TEST mode on the TOYOTA hand±
held tester.
CHECK:
Check operation of the VSV when it is operated by the TOYOTA
hand±held tester.
OK:
EGR system is OFF:
Air from port E is flowing out through the air filter.
EGR system is ON:
Air from port E is flowing out port G.
OK Go to step 4.
NG
3 Check operation of the VSV for EGR (See page SF±43).
NG Replace VSV for EGR.
OK
Check for open and short in harness and con-
nector between engine room J/B No.2 and
ECM (See page IN±31).