1999 TOYOTA CAMRY change time

DI±272
± DIAGNOSTICSENGINE (1MZ±FE)
507 Author: Date:
DTC P0171 System too Lean (Fuel Trim)
(Except California Spec.)
DTC P0172 System too Rich (Fuel Trim)
(Except California Spec.)
CIRCUIT DESCRIPTION
Fuel trim refers to the feedback compensation value compared against the basic injection time. Fuel trim
includes short±term fuel trim and long±term fuel trim.
Short±term fuel trim is the short±term fuel compensation used to maintain the air±fuel ratio at its ideal
theoretical value. The signal from the heated oxygen sensor indicates whether the air±fuel ratio is RICH or
LEAN compared to the ideal theoretical value, triggering a reduction in fuel volume if the air±fuel ratio is rich,
and an increase in fuel volume if it is lean.
Long±term fuel trim is overall fuel compensation carried out long±term to compensate for continual deviation
of the short±term fuel trim from the central value due to individual engine differences, wear over time and
changes in the usage environment.
If both the short±term fuel trim and long±term fuel trim are LEAN or RICH beyond a certain value, it is
detected as a malfunction and the MIL lights up.
DTC No.DTC Detecting ConditionTrouble Area
P0171
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on RICH side
(2 trip detection logic)

Air intake (hose loose)

Fuel line pressure

Injector blockage

Heated oxygen sensors (bank 1, 2 sensor 1) malfunction

Mass air flow meter

Engine coolant temp. sensor

Gas leakage on exhaust system
P0172
When air fuel ratio feedback is stable after engine warming up,
fuel trim is considerably in error on LEAN side
(2 trip detection logic)

Fuel line pressure

Injector leak, blockage

Heated oxygen sensors (bank 1, 2 sensor 1) malfunction

Mass air flow meter

Engine coolant temp. sensor

Gas leakage on exhaust system
HINT:

When DTC P0171 is recorded, the actual air±fuel ratio is on the LEAN side. When DTC P0172 is re-
corded, the actual air±fuel ratio is on the RICH side.

If the vehicle runs out of fuel, the air±fuel ratio is LEAN and DTC P0171 is recorded. The MIL then
comes on.

If the total of the short±term fuel trim value and long±term fuel trim value is within + 35 % (80°C (176°F)
or more), the system is functioning normally.
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.
DI4DR±01

DI±276
± DIAGNOSTICSENGINE (1MZ±FE)
511 Author: Date:
DTC P0300 Random/Multiple Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
DTC P0305 Cylinder 5 Misfire Detected
DTC P0306 Cylinder 6 Misfire Detected
CIRCUIT DESCRIPTION
Misfire: The ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes in
the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed change rate indicates that misfire has occurred.
When the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the
MIL lights up.
If the misfire rate is high enough and the driving conditions will cause catalyst overheating, the MIL blinks
when misfiring occurs.
DTC No.DTC Detecting ConditionTrouble Area
P0300Misfiring of random cylinders is detected during any
particular 200 or 1,000 revolutions
Ignition system

Injector

Fuel line pressure
P0301
P0302
P0303For any particular 200 revolutions for engine, misfiring is de-
tected which can cause catalyst overheating
(This causes MIL to blink)

EGR

Compression pressure

Valve clearance not to specification

Valve timing

Mass air flow meterP0303
P0304
P0305
P0306For any particular 1,000 revolutions of engine, misfiring is de-
tected which causes a deterioration in emission
(2 trip detection logic)

Mass air flow meter

Engine coolant temp. sensor

Open or short in engine wire

Connector connection

ECM
DI07S±07

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

FI7081
Waveform of Oxygen Sensor
before CatalystNormal Catalyst Waveform of Oxygen Sensor
after Catalyst
FI7132
Engine Speed
2,500 ~ 3,000 rpm
Idling
IG SW OFF(a)(b)(c) (d)
Time Warmed up 3 min. or so Check
± DIAGNOSTICSENGINE (1MZ±FE)
DI±305
540 Author: Date:
DTC P0420 Catalyst System Efficiency Below Threshold
(Except California Spec.)
CIRCUIT DESCRIPTION
The ECM compares the waveform of the oxygen sensor located before the catalyst with the waveform of
the oxygen sensor located after the catalyst to determine whether or not catalyst performance has deterio-
rated.
Air±fuel ratio feedback compensation keeps the waveform of the oxygen sensor before the catalyst repeat-
edly changing back and forth from rich to lean.
If the catalyst is functioning normally, the waveform of the oxygen sensor after the catalyst switches back
and forth between rich and lean much more slowly than the waveform of the oxygen sensor before the cata-
lyst.
But when both waveforms change at a similar rate, it indicates that catalyst performance has deteriorated.


DTC No.DTC Detecting ConditionTrouble Area
P0420
After engine and catalyst are warmed up, and while vehicle is
driven within set vehicle and engine speed range, waveforms
of heated oxygen sensors (bank 1 sensor 1, 2) have the same
amplitude
(2 trip detection logic)

Three±way catalytic converter

Open or short in heated oxygen sensor circuit

Heated oxygen sensor
CONFIRMATION ENGINE RACING PATTERN
DI07Y±06

Position
NORMALSHIFT SOLENOID NO.1
MALFUNCTIONING
Solenoid valveNo.1 No.2GearSHIFT SOLENOID NO.2
MALFUNCTIONINGBOTH SOLENOIDS MAL-
FUNCTIONINGSolenoid valve
No.1 No.2GearSolenoid valve
No.1 No.2GearGear when shift selector is
manually operated
D
2
LON
ONOFF
ON
ON OFF
OFF OFF
ON
ONOFF
ON
ON OFF
ON
ON ONOFF1st
2nd
3rd
O/D
1st
2nd
3rd
1st
2ndX
X
X
X
X
X
X
X
XON
ON
OFF
OFFON
ON
ON3rd 3rd
O/D
3rd
3rd
1st
2ndX
X
X
X
X
X
X
X
X ON
ON OFF OFF
OFF
ON
ON1st
1st O/D O/D
3rd
1st
1stO/D O/D O/D
O/D
3rd 3rd
3rd
1st
1st
X: MalfunctionsON
ON3rd
3rdO/D
3rd
OFF OFF
± DIAGNOSTICSAUTOMATIC TRANSAXLE (A140E)
DI±413
648 Author: Date:
DTC P0753, P0758 Shift Solenoid A/B Electrical Malfunc-
tion (Shift Solenoid Valve No.1/No.2)
CIRCUIT DESCRIPTION
Shifting from 1st to O/D is performed in combination with ON and OFF of the shift solenoid valves No.1 and
No.2 controlled by ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM con-
trols the remaining normal shift solenoid valve to allow the vehicle to be operated smoothly (Fail safe func-
tion).
Fail Safe Function:
If either of the shift solenoid valve circuits develops an open or short, the ECM turns the other shift solenoid
ON and OFF to shift to the gear positions shown in the table below. The ECM also turns the shift solenoid
valve SL OFF at the same time. If both solenoids are malfunction, hydraulic control cannot be performed
electronically and must be done manually.
Manual shifting as shown in the following table must be done (In the case of a short circuit, the ECM stops
sending current to the short circuited solenoid).
Check the shift solenoid valve No.1 when DTC P0753 is output and check the shift solenoid valve No.2 when
DTC P0758 is output.
DTC No.DTC Detecting ConditionTrouble Area
P0753
P0758
The ECM checks for an open or short circuit in the shift sole-
noid valves No.1 and No.2 circuit when it changes gear posi-
tion.
The ECM records DTC P0753 or P0758 if condition (a) or (b) is
detected once, but it does not light up MIL.
After 1 sec. ECM detects condition (a) or (b) in a trip again, it
causes the MIL to light up.
(a) When the solenoid is energized, the solenoid resistance is
8 W or less and is counted.
(b) When the solenoid is not energized, the solenoid resistance
is 100 kW or more and is counted.

Open or short in shift solenoid valve No.1/No.2 circuit

Shift solenoid valve No.1/No.2

ECM
DI033±02

Position
NORMALSHIFT SOLENOID NO.1
MALFUNCTIONING
Solenoid valveNo.1 No.2GearSHIFT SOLENOID NO.2
MALFUNCTIONINGBOTH SOLENOIDS MAL-
FUNCTIONINGSolenoid valve
No.1 No.2GearSolenoid valve
No.1 No.2GearGear when shift selector is
manually operated
D
2
LON
ONOFF
ON
ON OFF
OFF OFF
ON
ONOFF
ON
ON OFF
ON
ON ONOFF1st
2nd
3rd
O/D
1st
2nd
3rd
1st
2ndX
X
X
X
X
X
X
X
XON
ON
OFF
OFFON
ON
ON3rd 3rd
O/D
3rd
3rd
1st
2ndX
X
X
X
X
X
X
X
X OFF
OFFON
ON OFF OFF
OFF
ON
ON1st
O/D
O/D1st O/D O/D
O/D
1st
1stO/D O/D O/D
O/D
O/D O/D
O/D
1st
1st
X: MalfunctionsON
ON3rd
3rd
DI±462
± DIAGNOSTICSAUTOMATIC TRANSAXLE (A541E)
697 Author: Date:
DTC P0753, P0758 Shift Solenoid A/B Electrical Malfunc-
tion (Shift Solenoid Valve No.1/No.2)
CIRCUIT DESCRIPTION
Shifting from 1st to O/D is performed in combination with ON and OFF of the shift solenoid valves No.1 and
No.2 controlled by ECM. If an open or short circuit occurs in either of the shift solenoid valves, the ECM con-
trols the remaining normal shift solenoid valve to allow the vehicle to be operated smoothly (Fail safe func-
tion).
Fail Safe Function:
If either of the shift solenoid valve circuits develops an open or short, the ECM turns the other shift solenoid
ON and OFF to shift to the gear positions shown in the table below. The ECM also turns the shift solenoid
valve SL OFF at the same time. If both solenoids are malfunction, hydraulic control cannot be performed
electronically and must be done manually.
Manual shifting as shown in the following table must be done (In the case of a short circuit, the ECM stops
sending current to the short circuited solenoid).
Check the shift solenoid valve No.1 when DTC P0753 is output and check the shift solenoid valve No.2 when
DTC P0758 is output.
DTC No.DTC Detecting ConditionTrouble Area
P0753
P0758
The ECM checks for an open or short circuit in the shift sole-
noid valves No.1 and No.2 circuit when it changes.
The ECM records DTC P0753 or P0758 if condition (a) or (b) is
detected once, but it does not light up MIL.
After ECM detects condition (a) or (b) continuously 8 times or
more in a trip and the MIL light up.
(a) When the solenoid is energized, the solenoid resistance
is 8 W or less and is counted.
(b) When the solenoid is not energized, the solenoid resistance
is 100 kW or more and is counted.

Open or short in shift solenoid valve No.1/No.2 circuit

Shift solenoid valve No.1/No.2

ECM
DI02L±02

BR3583
BR3582F00010
RotorSpeed Sensor
Magnet
To ECU
+V
±VHigh Speed
Low Speed
CoilNS
DI±514
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM (DENSO Made)
749 Author: Date:
DTC31, 32, 33, 34Speed Sensor Circuit
CIRCUIT DESCRIPTION
The speed sensor detects wheel speed and sends the ap-
propriate signals to the ECU. These signals are used to control
the ABS system. The front and rear rotors each have 48 serra-
tions.
When the rotors rotate, the magnetic field emitted by the perma-
nent magnet in the speed sensor generates an AC voltage.
Since the frequency of this AC voltage changes in direct propor-
tion to the speed of the rotor, the frequency is used by the ECU
to detect the speed of each wheel.

DTC No.DTC Detecting ConditionTrouble Area
31, 32, 33, 34
Detection of any of conditions from 1. through 4.:
1. Vehicle speed is at 10 km/h (6 mph) or more and the
speed sensor signal circuit is open or short circuit con-
tinues for 15 sec. or more.
2. Momentary interruption of the speed sensor signal oc-
curs 7 times or more.
3. Vehicle speed is at 20 km/h (12mph) or more and inter-
ference on the speed sensor signal continues for 5 sec.
or more.
4. Open circuit condition of the speed sensor signal circuit
continues for 0.5 sec. or more.

Right front, left front, right rear, left rear speed sensor

Each speed sensor circuit

Speed sensor rotor
HINT:

DTC No. 31 is for the right front speed sensor.

DTC No. 32 is for the left front speed sensor.

DTC No. 33 is for the right rear speed sensor.

DTC No. 34 is for the left rear speed sensor.
Fail safe function:
If trouble occurs in the speed sensor circuit, the ECU cuts off current to the ABS solenoid relay and prohibits
ABS control.
DI1JM±02

BR3893
Malfunction Code (Example Code 72, 76)
72 67
ON
OFF
0.5 sec. 0.5 sec. 0.5 sec. 0.5 sec.1.5 sec.
2.5 sec.4 sec.
Repeat
H07517
TOYOTA
Hand±held Tester
DLC2
± DIAGNOSTICSANTI±LOCK BRAKE SYSTEM (BOSCH Made)
DI±541
776 Author: Date:
HINT:

See the list of DTC shown at the bottom of this page.

If every sensor is normal, a normal code is output (A cycle
of 0.25 sec. ON and 0.25 sec. OFF is repeated).

If 2 or more malfunctions are indicated at the same time,
the lowest numbered code will be displayed 1st.
(12) After doing the check, disconnect the SST from ter-
minals Tc and E
1 of DLC1, and turn ignition switch
OFF.
SST 09843 ± 18020
(b) Using TOYOTA hand±held tester, check the DTC.
(1) Do step 1. ~ 6. on the previous page.
(2) Hook up the TOYOTA hand±held tester to the
DLC2.
(3) Read the DTC by following the prompts on the tes-
ter screen.
Please refer to the TOYOTA hand±held tester oper-
ator 's manual for further details.
DTC of speed sensor check function:
Code No.DiagnosisTrouble Area
71Low output voltage of right front speed sensor

Right front speed sensor

Sensor installation

Right front speed sensor rotor
72Low output voltage of left front speed sensor

Left front speed sensor

Sensor installation

Left front speed sensor rotor
73Low output voltage of right rear speed sensor
Right rear speed sensor
Sensor installation
Right rear speed sensor rotor
74Low output voltage of left rear speed sensor

Left rear speed sensor

Sensor installation

Left rear speed sensor rotor
75Abnormal change in output voltage of right front speed
sensor
Right front speed sensor rotor
76Abnormal change in output voltage of left front speed
sensor
Left front speed sensor rotor
77Abnormal change in output voltage of right rear speed
sensor
Right rear speed sensor rotor
78Abnormal change in output voltage of left rear speed sensor
Left rear speed sensor rotor