TOYOTA AVALON 2001 Service Repair Manual
Manufacturer: TOYOTA, Model Year: 2001, Model line: AVALON, Model: TOYOTA AVALON 2001Pages: 1897, PDF Size: 26.61 MB
Page 911 of 1897
- DIAGNOSTICSENGINE
DI-27
183 Author: Date:
2001 AVALON (RM808U)
DTC P0101 Mass Air Flow Circuit Range/Performance
Problem
CIRCUIT DESCRIPTION
Refer to DTC P0100 on page DI-23.
DTC No.DTC Detecting ConditionTrouble Area
P0101
Conditions (a), (b) and (c) continue 10 sec. or more with en-
gine speed NE < 900: (2 trip detection logic)
(a) Throttle valve fully closed
(b) Mass air flow meter output 2.2 V
(c) THW 70°C
Mass air flow meterP0101
Conditions (a) and (b) continue 10 sec. or more with engine
speed 1,500 rpm or more: (2 trip detection logic)
(a) VTA 0.63 V
(b) Mass air flow meter output 1.06 V
Mass air flow meter
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 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 P0101) being output?
NO Replace mass air flow meter.
YES
Go to relevant DTC chart (See page DI-14).
DI07G-09
Page 912 of 1897
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°)
DI-28
- DIAGNOSTICSENGINE
184 Author: Date:
2001 AVALON (RM808U)
DTC P0110 Intake Air Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
The intake air temperature sensor is built into mass air flow me-
ter 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.
The 5 V power source voltage in the ECM is applied to the in-
take air temperature sensor from terminal THA via 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
function 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 (built into mass air flow meter)
ECM
HINT:
After confirming DTC P0110, use the OBD II scan tool or TOYOTA hand-held tester to confirm the intake
air temperature form the CURRENT DATA.
Temperature DisplayedMalfunction
-40°C ( -40°F )Open circuit
140°C ( 284°F ) or moreShort circuit
DI07H-10
Page 913 of 1897
A00310A09772
5 V
THA
E2
E1 22
18 4
5R Intake Air Temp. Sensor
(Built into Mass Air Flow Meter)ECM
L-B
W
E5 E5
- DIAGNOSTICSENGINE
DI-29
185 Author: Date:
2001 AVALON (RM808U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTCs P0110, P0115, P0120 and P1410 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 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 intake air 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).
Page 914 of 1897
A00210
ON
Intake Air
Temp. Sensor
ECM
5 V
E2
THA22
18 1
2E5
E5
BE6653
FI7055
A02019
ON
Intake Air Temp. SensorECM
5 V
E2 22
18 E5
E5
E2
THA
THA
DI-30
- DIAGNOSTICSENGINE
186 Author: Date:
2001 AVALON (RM808U)
2 Check for open in harness or ECM.
PREPARATION:
(a) Disconnect the mass air flow meter 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:
Temperature value: 1405C (2845F) or more
OK Confirm good connection at sensor. If OK, re-
place mass air flow meter.
NG
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove the glove compartment (See page SF-82).
(b) Connect between terminals THA and E2 of the ECM con-
nector.
HINT:
The mass air flow meter connector is disconnected. Before
checking, do a visual and contact pressure check for the ECM
connector (See page IN-30).
(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: 1405C (2845F) or more
OK Open in harness between terminal E2 or THA,
repair or replace harness.
NG
Confirm good connection at ECM. If OK,
check and replace ECM (See page IN-30).
Page 915 of 1897
A00212
ON
Intake Air
Temp. Sensor
ECM
5 V
E2 22
18
THA
BE6653
FI7054E5
E5
A02043
ON
Intake Air Temp. Sensor
E5 ConnectorECM
5 V
E2 THA
- DIAGNOSTICSENGINE
DI-31
187 Author: Date:
2001 AVALON (RM808U)
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the mass air flow meter 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: -405C (-405F)
OK Replace mass air flow meter.
NG
5 Check for short in harness or ECM.
PREPARATION:
(a) Remove the glove compartment (See page SF-82).
(b) Disconnect the E5 connector from the ECM.
HINT:
Mass air flow meter 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: -405C (-405F)
OK Repair or replace harness or connector.
NG
Check and replace ECM (See page IN-30).
Page 916 of 1897
A00310
A09772
Engine Coolant Temp. SensorECM
5 V
THW
E2
E1 14
18 2
1G-Y
W
E5 E5 DI-32
- DIAGNOSTICSENGINE
188 Author: Date:
2001 AVALON (RM808U)
DTC P0115 Engine Coolant Temp. Circuit Malfunction
CIRCUIT DESCRIPTION
A thermistor built into the engine coolant temperature sensor changes the resistance value according to the
engine coolant temperature.
The structure of the sensor and connection to the ECM is the same as in the intake air temperature circuit
malfunction shown on page DI-28.
If the ECM detects the DTC P0115, it operates the fail-safe function in which the engine coolant temperature
is assumed to be 80°C (176°C).
DTC No.DTC Detecting ConditionTrouble Area
P0115Open or short in engine coolant temp. sensor circuit
Open or short in engine coolant temp. sensor circuit
Engine coolant temp. sensor
ECM
HINT:
After confirming DTC P0115, use the OBD II scan tool or TOYOTA hand-held tester to confirm the engine
coolant temperature from the CURRENT DATA.
Temperature DisplayedMalfunction
-40°C (-40°F)Open circuit
140°C (284°F) or moreShort circuit
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTCs P0110, P0115, P0120 and P1410 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 was warmed up or not, the air-fuel
ratio was lean or rich etc. at the time of the malfunction.
DI07I-09
Page 917 of 1897
A00214
ON
Engine Coolant
Temp. Sensor
ECM
5V
E2 14
18 2
1
THW
BE6653
FI7055
E5 E5
- DIAGNOSTICSENGINE
DI-33
189 Author: Date:
2001 AVALON (RM808U)
1 Connect OBD II scan tool or TOYOTA hand-held tester, and read value of engine
coolant 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 engine coolant 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 engine coolant temp. 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:
Temperature value: 1405C (2845F) or more
OK Confirm good connection at sensor. If OK, re-
place engine coolant temperature sensor.
NG
Page 918 of 1897
A02020
ON
Engine Coolant Temp. Sensor
E2
THWECM
5 V
E2 2
114
18 E5
E5THW
A00216
ON
Engine Coolant
Temp. Sensor
ECM
5 V
E2 14
18
E5
E5THW
FI7054 BE6653
DI-34
- DIAGNOSTICSENGINE
190 Author: Date:
2001 AVALON (RM808U)
3 Check for open in harness or ECM.
PREPARATION:
(a) Remove the glove compartment (See page SF-82).
(b) Connect between terminals THW and E2 of the ECM con-
nector.
HINT:
The engine coolant temperature sensor connector is discon-
nected. Before checking, do a visual and contact pressure
check for the ECM connector (See page IN-30).
(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: 1405C (2845F) or more
OK Open in harness between terminal E2 or THW,
repair or replace harness.
NG
Confirm good connection at ECM. If OK,
check and replace ECM (See page IN-30).
4 Check for short in harness and ECM.
PREPARATION:
(a) Disconnect the engine coolant temperature sensor con-
nector.
(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: -405C (-405F)
OK Replace engine coolant temperature sensor.
NG
Page 919 of 1897
A02043
ON
Engine Coolant Temp. SensorECM
5 V
E2 THW
E5 Connector
- DIAGNOSTICSENGINE
DI-35
191 Author: Date:
2001 AVALON (RM808U)
5 Check for short in harness or ECM.
PREPARATION:
(a) Remove the glove compartment (See page SF-82).
(b) Disconnect the E5 connector from the ECM.
HINT:
The engine coolant temperature sensor connector is discon-
nected.
(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: -405C (-405F)
OK Repair or replace harness or connector.
NG
Check and replace ECM (See page IN-30).
Page 920 of 1897
DI-36
- DIAGNOSTICSENGINE
192 Author: Date:
2001 AVALON (RM808U)
DTC P0116 Engine Coolant Temp. Circuit Range/Perfor-
mance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0115 on page DI-32.
DTC No.DTC Detecting ConditionTrouble Area
If THW -7°C (19.4°F), 20 min. or more after starting engine,
engine coolant temp. sensor value is 20°C (68°F) or less (2
trip detection logic)
If THW -7°C (19.4°F), and <10°C (50°F), 5 min. or more
after starting engine, engine coolant temp. sensor value is
20°C (95°F) or less (2 trip detection logic)
If THW 10°C (50°F), 2 min. or more after starting engine,
engine coolant temp. sensor value is 30°C (86°F) or less (2
trip detection logic)
Cooling systemP0116When THW 35°C (95°F) or more and less than 60°C
(140°F), and THA - 6.7°C (19.9°F) or more, when starting
engine, conditions (a) and (b) continue: (2 trip detection logic)
(a) Vehicle speed is changing (Not stable)
(b) THW change is lower than 3°C (5.4°F) from THW since
when starting engineCooling system
Engine coolant temp. sensor
In case that reading value of water temp. sensor will not
change more than 1°C (1.8°F) even after repeating 6 trips
(detection logic) of adjusting speed pattern with THW more
than 60°C (140°F) when engine starts.
INSPECTION PROCEDURE
HINT:
If DTCs P0115 and P0116 are output simultaneously, engine coolant temperature sensor circuit may
be open. Perform troubleshooting of DTC P0115 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 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 P0116) being output?
YES Go to relevant DTC chart (See page DI-14).
NO
2 Check thermostat (See page CO-1 1).
NG Replace thermostat.
DI07J-09