TOYOTA CAMRY 1999 Service Repair Manual

DI00M±05
P01242
Manifold Absolute Pressure450
150 1.2
750 3.6 (3.96)
2.4V
100mmHg
20(840)
60kPa
(112)
Output Voltage
± DIAGNOSTICSENGINE (5S±FE)
DI±29
264 Author: Date:
CIRCUIT INSPECTION
DTC P0105 Manifold Absolute Pressure/Barometric
Pressure Circuit Malfunction
CIRCUIT DESCRIPTION
By a built±in sensor unit, the manifold absolute pressure sensor
detects the intake manifold pressure as a voltage. The ECM
then determines the basic injection duration and basic injection
advance angle based on this voltage. Since the manifold abso-
lute pressure sensor does not use the atmospheric pressure as
a criterion, but senses the absolute pressure inside the intake
manifold (the pressure in proportion to the present absolute
vacuum 0), it is not influenced by fluctuations in the atmospheric
pressure due to high altitude and other factors. This permits it
to control the air±fuel ratio at the proper lever under all condi-
tions.
DTC No.DTC Detecting ConditionTrouble Area
P0105Open or short in manifold absolute pressure sensor circuit

Open or short in manifold absolute pressure sensor circuit

Manifold absolute pressure sensor

ECM
HINT:
After confirming DTC P0105, use the OBD II scan tool or TOYOTA hand±held tester to confirm the manifold
absolute pressure from the CURRENT DATA.
Manifold Absolute Pressure (kPa)Malfunction
Approx. 0
PIM circuit short
130 or more

VC circuit open or short

PIM circuit open

E2 circuit open

A00309
ECM Manifold Absolute
Pressure Sensor
1PIMVC
E2 Y
B±Y
BRE8
E8
E8 3
25 V
E1 1
2
9 DI±30
± DIAGNOSTICSENGINE (5S±FE)
265 Author: Date:
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTC P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction), P0106 (Manifold
Absolute Pressure /Barometric Pressure Circuit Range/Performance Problem) and P0110 (Intake Air
Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction), P0120 (Throttle/Pedal
Position Sensor/Switch ºAº Circuit Malfunction) are output simultaneously, E2 (sensor ground) may be
open.

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.

BE6653P23721A03008A03407
w/o Immobiliser
w/ ImmobiliserE2 (±)
VC (+)
ON
E2 (±)
VC (+)
± DIAGNOSTICSENGINE (5S±FE)
DI±31
266 Author: Date:
1 Connect OBD II scan tool or TOYOTA hand±held tester, and read value of man-
ifold absolute pressure.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool or TOYOTA hand±held tester main switch
ON.
CHECK:
Read value of the manifold absolute pressure on the OBD II scan tool or TOYOTA hand±held tester.
OK:
Same as atmospheric pressure.
OK Check for intermittent problems
(See page DI±3).
NG
2 Check voltage between terminals VC and E2 of ECM connector.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals VC and E2 of the ECM
connector.
OK:
Voltage: 4.5 ± 5.5 V
NG Check and replace ECM (See page IN±31).
OK

BE6653P23722A03009A03408
w/o Immobiliser
w/ ImmobiliserPIM (+)E2 (+)
ON
PIM (+)
E2 (+)
DI±32
± DIAGNOSTICSENGINE (5S±FE)
267 Author: Date:
3 Check voltage between terminals PIM and E2 of ECM connector.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure voltage between terminals PIM and E2 of the ECM
connector.
OK:
Voltage: 3.3 ± 3.9 V
OK Check and replace ECM (See page IN±31).
NG
4 Check for open and short in harness and connector between manifold absolute
pressure sensor and ECM.
NG Repair or replace harness or connector.
OK
Replace manifold absolute pressure sensor
(See page SF±52).

± DIAGNOSTICSENGINE (5S±FE)
DI±33
268 Author: Date:
DTC P0106 Manifold Absolute Pressure Circuit
Range/Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction) on page
DI±29.
DTC No.DTC Detecting ConditionTrouble Area
P0106
After engine is warmed up, conditions (a) and (b) continue with
engine speed 400 ~ 1,000 rpm
(2 trip detection logic)
(a) Throttle valve fully closed
(b) Manifold absolute pressure sensor output > 3.0 V

Manifold absolute pressure sensorP0106Condition (c) and (d) continue with engine speed 2,500 rpm or
less
(2 trip detection logic)
(c) VTA > 1.85
(d) Manifold absolute pressure sensor output < 1.0 V

Manifold absolute ressure sensor

Vacuum line
WIRING DIAGRAM
Refer to DTC P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction) on page
DI±29.
INSPECTION PROCEDURE
HINT:

If DTC P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction) and P0106 (Man-
ifold Absolute Pressure /Barometric Pressure Circuit Range/Performance Problem) are output simul-
taneously, manifold absolute pressure sensor circuit may be open. Perform troubleshooting of DTC
P0105 first.

If DTC P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction), P0106 (Manifold
Absolute Pressure /Barometric Pressure Circuit Range/Performance Problem), P0110 (Intake Air
Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction) and P0120 (Throttle/
Pedal Position Sensor/Switch ºAº Circuit Malfunction) are output simultaneously, E2 (sensor ground)
may be open.

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 Are there any other codes (besides DTC P0106) being output?
YES Go to relevant DTC chart.
NO
DI00N±04

DI±34
± DIAGNOSTICSENGINE (5S±FE)
269 Author: Date:
2 Check manifold absolute pressure sensor operation (See page SF±52).
OK Check vacuum line between intake air chamber
and manifold absolute pressure sensor.
NG
Replace manifold absolute pressure sensor.

FI4741
(fig.1)
Acceptable
Resistance kW
± 20 0 20 40 60 80 100
(± 4) (32) (68) (104) (140) (176) (212) 30
20
10
5
3
2
1
0.5
0.3
0.2
0.1
Te m p .°C (F°)
± DIAGNOSTICSENGINE (5S±FE)
DI±35
270 Author: Date:
DTC P0110 Intake Air Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
The intake air temp. sensor is built into the air cleaner cap and
senses the intake air temperature.
A thermistor built in the sensor changes the resistance value
according to the intake air temperature, the lower the intake air
temperature, the greater the thermistor resistance value, and
the higher the intake air temperature, the lower the thermistor
resistance value (See fig.1).
The air intake temperature sensor is connected to the ECM
(See below). The 5 V power source voltage in the ECM is ap-
plied to the intake air temp. sensor from the terminal THA via
a resistor R.
That is, the resistor R and the intake air temp. sensor are con-
nected in series. When the resistance value of the intake air
temp. sensor changes in accordance with changes in the intake
air temperature, the potential at terminal THA also changes.
Based on this signal, the ECM increases the fuel injection vol-
ume to improve driveability during cold engine operation.
If the ECM detects the DTC P0110, it operates the fail safe func-
tion in which the intake air temperature is assumed to be 20°C
(68°F).
DTC No.DTC Detecting ConditionTrouble Area
P0110Open or short in intake air temp. sensor circuit

Open or short in intake air temp. sensor circuit

Intake air temp. sensor

ECM
HINT:
After confirming DTC P0110, use the OBD II scan tool or TOYOTA hand±held tester to confirm the intake
air temperature from the CURRENT DATA.
Temperature DisplayedMalfunction
±40°C (±40°F)Open circuit
140°C (284°F) or moreShort circuit
DI00O±05

A00310
Intake Air Temp. Sensor
E8
E83
9ECM
5 V
THA
E2
E1 R
Y±B
BR 2
1 DI±36
± DIAGNOSTICSENGINE (5S±FE)
271 Author: Date:
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTCs P0105 (Manifold Absolute Pressure/Barometric Pressure Circuit Malfunction), P0106 (Man-
ifold Absolute Pressure /Barometric Pressure Circuit Range/Performance Problem), P0110 (Intake Air
Temp. Circuit Malfunction), P0115 (Engine Coolant Temp. Circuit Malfunction) and P0120 (Throttle/
Pedal Position Sensor/Switch ºAº Circuit Malfunction) are output simultaneously, E2 (sensor ground)
may be open.

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.

A00391
ECM
13
2
9 Intake Air Temp.
Sensor
E85 V
E8THA
E2
E1
ON
± DIAGNOSTICSENGINE (5S±FE)
DI±37
272 Author: Date:
1 Connect OBD II scan tool or TOYOTA hand±held tester, and read value of intake
air temperature.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand±held tester to DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool or TOYOTA hand±held tester main switch
ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA hand±held tester.
OK:
Same as actual air intake temperature.
HINT:

If there is open circuit, OBD II scan tool or TOYOTA hand±held tester indicates ± 40°C (± 40°F).

If there is short circuit, OBD II scan tool or TOYOTA hand-held tester indicates 140°C (284°F) or more.
NG ±40°C (±40°F) .... Go to step 2.
140°C (284°F) or more .... Go to step 4.
OK
Check for intermittent problems
(See page DI±3).
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the intake air temp. sensor connector.
(b) Connect the sensor wire harness terminals together.
(c) Turn the ignition switch ON.
CHECK:
Read temp. value on the OBD II scan tool or TOYOTA hand±
held tester.
OK:
Temp. value: 140°C (284°F) or more
OK Confirm good connection at sensor. If OK, re-
place intake air temp. sensor.
NG

A03010A03409
Intake Air Temp.
SensorECM
3
9
E8E8THA
E25 V
ON
E1
THAE2
w/o Immobiliser
w/ Immobiliser
THA
E2
DI±38
± DIAGNOSTICSENGINE (5S±FE)
273 Author: Date:
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove the glove compartment (See page SF±64).
(b) Connect between terminals THA and E2 of the ECM con-
nector.
HINT:
The intake air temp. sensor connector is disconnected.
Before checking, do a visual and contact pressure check for the
ECM connector (See page IN±31).
(c) Turn the ignition switch ON.
CHECK:
Read temperature value on the OBD II scan tool or TOYOTA
hand±held tester.
OK:
Temperature value: 140°C (284°F) or more
OK Open in harness between terminals E2 or THA,
repair or replace harness.
NG
Confirm good connection at ECM. If OK,
check and replace ECM (See page IN±31).