TOYOTA CAMRY 1999 Service Repair Manual

DI±20
± DIAGNOSTICSENGINE
PCNG1 (E7±7) ± E2 (E5±9)
G±R e BR
IG switch ON, Needle position of fuel level gauge 4/4
3/4
2/4
1/43.3
2.7
2.0
1.3
*: The ECM terminal voltage is fixed regardless of the output voltage from the sensor.

DI00L±08
± DIAGNOSTICSENGINE
DI±21
PROBLEM SYMPTOMS TABLE
SymptomSuspect AreaSee page
Engine does not crank (Does not start)6. Starter
7. Starter relay*1
*2
No initial combustion (Does not start)
1. ECM power source circuit
2. Fuel shutoff valve circuit
3. ECMDI±116
DI±86
IN±29
No complete combustion (Does not start)1. Fuel shutoff valve circuitDI±86
Engine cranks normally (Difficult to start)
1. Starter signal circuit
2. Fuel shutoff valve circuit
3. CompressionDI±113
DI±86
EM±3
Cold engine (Difficult to start)1. Starter signal circuit
2. Fuel shutoff valve circuitDI±113
DI±86
Hot engine (Difficult to start)1. Starter signal circuit
2. Fuel shutoff valve circuitDI±113
DI±86
High engine idle speed (Poor idling)1. A/C switch circuit
2. ECM power source circuit*3
DI±116
Low engine idle speed (Poor idling)1. A/C switch circuit
2. Fuel shutoff valve circuit*3
DI±86
Rough idling (Poor idling)1. Compression
2. Fuel shutoff valve circuitEM±3
DI±86
Hunting (Poor idling)1. ECM power source circuit
2. Fuel shutoff valve circuitDI±116
DI±86
Hesitation/Poor acceleration (Poor driveability)1. Fuel shutoff valve circuit
2. A/T faultyDI±86
DI±148
Surging (Poor driveability)1. Fuel shutoff valve circuitDI±86
Soon after starting (Engine stall)1. Fuel shutoff valve circuitDI±86
During A/C operation (Engine stall)1. A/C switch circuit
2. ECM*3
IN±29
A/C switch indicatior blinking1. A/C Compressor lock sensor circuit
2. A/C Evaporator temp. sensor circuitDI±119
DI±121
*1: See Pub. No. RM654U, page ST±2.
*2: See Pub. No. RM654U, page ST±20.
*3: See Pub. No. RM654U, page AC±84.

DI00M±07
P01242
Manifold Absolute Pressure450
150 1.2
750 3.6 (3.96)
2.4V
100mmHg
20(840)
60kPa
(112)
Output Voltage
DI±22
± DIAGNOSTICSENGINE
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
BRE5
E5
E5 3
25 V
E1 1
2
9
± DIAGNOSTICSENGINE
DI±23
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTCs P0105, P0106, P0110, P0115, P0120, P0180 and P0190 are output simultaneously, E2 (sen-
sor 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 was warmed up or not, the air±fuel
ratio was lean or rich, etc. at the time of the malfunction.
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 the 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

BE6653A03008A09254
E2 VC
ON
(±) (+)
A03009BE6653A09255
PIME2
(±) (+)
DI±24
± DIAGNOSTICSENGINE
2 Check voltage between terminals VC and E2 of ECM connector.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Turn the ignition switch ON.
CHECK:
Measure the 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±29).
OK
3 Check voltage between terminals PIM and E2 of ECM connector.
PREPARATION:
(a) Remove the glove compartment.
(b) Turn the ignition switch ON.
CHECK:
Measure the 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±29).
NG
4 Check for open and short in harness and connector between manifold absolute
pressure sensor and ECM (See page IN±29).
NG Repair or replace harness or connector.
OK
Replace manifold absolute pressure sensor
(See Pub. No. RM654U, page SF±52).

± DIAGNOSTICSENGINE
DI±25
DTC P0106 Manifold Absolute Pressure Circuit Range/
Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0105 on page DI±22.
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

Vacuum lineP0106Conditions (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

Vacuum line

Manifold absolute pressure sensor
INSPECTION PROCEDURE
HINT:

If DTCs P0105, P0106, P0110, P0115, P0120 and P0180 are output simultaneously, manifold abso-
lute pressure sensor circuit may be open. Perform troubleshooting of DTC P0105 first.

If DTCs P0105, P0106, P0110, P0115, P0120, P0180 and P0190 are output simultaneously, E2 (sen-
sor 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 was warmed up or not, the air±fuel
ratio was 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
2 Check manifold absolute pressure sensor operation (See Pub. No. RM654U,
page SF±53).
OK Check vacuum line between intake air chamber
and manifold absolute pressure sensor.
NG
Replace manifold absolute pressure sensor.
DI00N±06

A09428
(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°)
DI±26
± DIAGNOSTICSENGINE
DTC P0110 Intake Air Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
The intake air temperature 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 intake air 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 temperature sensor from terminal THA via
a resistor R.
That is, resistor R and the intake air temperature sensor are
connected in series. When the resistance value of the intake air
temperature 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 in-
jection volume to improve driveability during cold engine opera-
tion.
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±07

A00310
Intake Air Temp. Sensor
E5
E53
9ECM
5 V
THA
E2
E1 R
Y±B
BR 2
1
± DIAGNOSTICSENGINE
DI±27
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTCs P0105, P0106, P0110, P0115, P0120, P0180 and P0190 are output simultaneously, E2 (sen-
sor 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 was warmed up or not, the air±fuel
ratio was lean or rich, etc. at the time of the malfunction.
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 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 the 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).

A00391
ECM
13
2
9 Intake Air Temp.
Sensor
E55 V
E5THA
E2
E1
ON
A03010A09256
Intake Air Temp.
SensorECM
3
9
E5 E5THA
E25 V
ON
E1
THAE2
DI±28
± DIAGNOSTICSENGINE
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the intake air temperature sensor connector.
(b) Connect the sensor wire harness terminals together.
(c) Turn the ignition switch ON.
CHECK:
Read the temperature value on the OBD II scan tool or TOYO-
TA hand±held tester.
OK:
Temp. value: 140°C (284°F) or more
OK Confirm good connection at sensor. If OK, re-
place intake air temperature sensor.
NG
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Connect between terminals THA and E2 of the ECM con-
nector.
HINT:
The intake air temperature sensor connector is disconnected.
Before checking, do a visual and contact pressure check for the
ECM connector (See page IN±29).
(c) Turn the ignition switch ON.
CHECK:
Read the temperature value on the OBD II scan tool or TOYO-
TA 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±29).

A00393
ON
Intake Air Temp.
Sensor
2
1ECM
3
9
THA
E2
E15 V
E5
E5
A03011A09257
Intake Air Temp.
SensorECM
THA
E25 V
E1
ON
E5 Connector
± DIAGNOSTICSENGINE
DI±29
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the intake air temperature sensor connector.
(b) Turn the ignition switch ON.
CHECK:
Read the temperature value on the OBD II scan tool or TOYO-
TA hand±held tester.
OK:
Temperature value: ±40°C (±40°F)
OK Replace intake air temperature sensor.
NG
5 Check for short in harness or ECM.
PREPARATION:
(a) Remove the glove compartment (See Pub. No. RM654U,
page SF±64).
(b) Disconnect the E5 connector from the ECM.
HINT:
The intake air temperature sensor connector is disconnected.
(c) Turn the ignition switch ON.
CHECK:
Read the temperature value on the OBD II scan tool or TOYO-
TA hand±held tester.
OK:
Temperature value: ±40°C (±40°F)
OK Repair or replace harness or connector.
NG
Check and replace ECM (See page IN±29).