2005 TOYOTA AVENSIS diagnostic

A18294
THWE2
ECM Connector
E13
A65743
THWE2
ECM Connector
E13
A76786
Wire Harness Side
E2Engine Coolant Temperature
Sensor Connector
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±203
AVENSIS REPAIR MANUAL (RM1018E)
When not using hand±held tester:
1INSPECT ECM(THW VOLTAGE)
(a)Turn the ignition switch ON.
(b)Measure the voltage between terminals THW and E2 of
the ECM connector.
Voltage:
Intake air temp.Voltage
20
C (68
F)0.5 to 3.4 V
60
C (140
F)0.2 to 1.0 V
OKCHECK FOR INTERMITTENT PROBLEMS
(See page 05±149)
NG
2INSPECT ENGINE COOLANT TEMPERATURE SENSOR (See page 10±20)
NGREPLACE ENGINE COOLANT TEMPERATURE SENSOR
OK
3CHECK HARNESS AND CONNECTOR(ECM ± EFI WATER TEMP. SENSOR)
(a)Disconnect the E13 ECM connector.
(b)Disconnect the engine coolant temperature sensor con- nector.
(c)Check for continuity between the wire harness side con- nector.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
THW (E13±19) ± Engine coolant temperature sensor (E2±2)ContinuityE2 (E13±28) ± Engine coolant temperature sensor (E2±1)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
THW (E13±19) or Engine coolant temperature sensor (E2±2)
± Body groundContinuity
MGREPAIR OR REPLACE HARNESS ORCONNECTOR
OK
CHECK AND REPLACE ECM (See page 01±32)

± 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
A67628
Acceptable (Fig.1)
Resistance K

Temp. C (F)
05±194
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0110/24 INTAKE AIR TEMPERATURE CIRCUIT
MALFUNCTION
DTC P0112/24 INTAKE AIR TEMPERATURE CIRCUIT LOW
INPUT
DTC P0113/24 INTAKE AIR TEMPERATURE CIRCUIT HIGH
INPUT
CIRCUIT DESCRIPTION
The intake air temperature sensor is built in the mass air flow
meter 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 is the greater the thermis-
tor resistance value becomes and the higher the intake air tem-
perature is the lower the thermistor resistance value becomes
(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
(THAR) via resistor R.
That is, the 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 (THAR)
also changes. Based on this signal, the ECM increases the fuel
injection volume to improve the driveability during cold engine
operation.
DTC No.Proceed toDTC Detection ConditionTrouble Area
P0110/24Step 1
Open or short in intake air
temp. sensor circuit for 0.5
sec.

Open or short in intake air temperature sensor circuit
P0112/24Step 4Short in intake air temp. sen-
sor circuit for 0.5 sec.

Oen or short in intake air tem erature sensor circuit

Intake air temperature sensor (built in mass air flow meter)

ECM
P0113/24Step 2Open in intake air temp. sen-
sor circuit for 0.5 sec.
After confirming DTC ºP0110/24, P0112/24 or P0113/24º, use the hand±held tester to confirm the intake air
temperature from the ºDIAGNOSIS / OBD/MOBD / DATA LIST / ALLº.
Temperature DisplayedMalfunction
±40C (±40Open circuit
140C (284  Short circuit
05C7G±01

A72925
BR
G±R
28
20
E13 THA
E2 ECM
5 4
A6
Intake Air Temperature Sensor
(Built in Mass Air Flow Meter)
E135V
R
THA
E2
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±195
AVENSIS REPAIR MANUAL (RM1018E)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If different DTCs that are related to a different system are output simultaneously while terminal E2 is
used as a ground terminal, terminal E2 may be open.

Read freeze frame data using
\b\b
\b 
\f
 Freeze frame data records the engine conditions
when a malfunction is detected. When troubleshooting, it is useful for d\
etermining whether the vehicle
was running or stopped, the engine was warmed up or not, the air±fuel ra\
tio was lean or rich, etc. at
the time of the malfunction.
When using hand±held tester:
1READ VALUE OF HAND±HELD TESTER(INTAKE AIR TEMPERATURE)
(a)Connect the hand±held tester to the DLC3.
(b)Turn the ignition switch ON and push the hand±held tester main switch \
ON.
(c)Select the item ºDIAGNOSIS / OBD/MOBD / DATA LIST / ALL / INTAKE AIRº and read its value dis- played on the hand±held tester.
Temperature: Same value as the actual intake air temperature.
Result:
Temperature DisplayedProceed to
±40C (±40 )A
140 C (284 ) or moreB
OK (Same as present temperature)C
HINT:

If there is an open circuit, the hand±held tester indicates ±40 C (±40 F).

If there is a short circuit, the hand±held tester indicates 140 C (284 F) or more.
BGo to step 4
CCHECK FOR INTERMITTENT PROBLEMS (See page 05±149)
A

A75743
Mass Air flow meterECM
A54396
A6
Wire Harness Side
Mass Air Flow Meter ConnectorE2
THA
A75742
ECM
Mass Air flow meter
A18294
THAE2
ECM Connector
E13
05±196
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
2 READ VALUE OF HAND±HELD TESTER(CHECK FOR OPEN IN WIRE HARNESS)
(a) Disconnect the mass air flow meter connector.
(b) Connect terminals THA and E2 of the mass air flow meter
connector.
(c) Turn the ignition switch ON.
(d) Select the item ºDIAGNOSIS / OBD/MOBD / DATA LIST
/ ALL / INTAKE AIRº and read its value displayed on the
hand±held tester.
Temperature value: 140
C (284
F) or more
OK CONFIRM GOOD CONNECTION AT SENSOR. IF
OK, REPLACE MASS AIR FLOW METER
NG
3 READ VALUE OF HAND±HELD TESTER(CHECK FOR OPEN IN ECM)
(a) Disconnect the mass air flow meter connector.
(b) Connect terminals THA and E2 of the E13 ECM connec-
tor.
HINT:
Before checking, do a visual and contact pressure check for the
ECM connector.
(c) Turn the ignition switch ON.
(d) Select the item ºDIAGNOSIS / OBD/MOBD / DATA LIST
/ ALL / INTAKE AIRº and read its value displayed on the
hand±held tester.
Temperature value: 140
C (284
F) or more
OK REPAIR OR REPLACE HARNESS OR
CONNECTOR
NG

A75766
ECM
Mass Air Flow
Meter Connector
A75744
ECM
Mass Air flow meter
A65743
E13
ECM Connector
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±197
AVENSIS REPAIR MANUAL (RM1018E)
CONFIRM GOOD CONNECTION AT ECM. IF OK, CHECK AND REPLACE ECM (See page 01±32)
4READ VALUE OF HAND±HELD TESTER(CHECK FOR SHORT IN WIRE HARNESS)
(a)Disconnect the mass air flow meter connector.
(b)Turn the ignition switch ON.
(c)Select the item ºDIAGNOSIS / OBD/MOBD / DATA LIST
/ ALL / INTAKE AIRº and read its value displayed on the
hand±held tester.
Temperature value: ±40
C (±40
F)
OKREPLACE MASS AIR FLOW METER
NG
5READ VALUE OF HAND±HELD TESTER(CHECK FOR SHORT IN ECM)
(a)Disconnect the E13 ECM connector.
(b)Turn the ignition switch ON.
(c)Select the item ºDIAGNOSIS / OBD/MOBD / DATA LIST / ALL / INTAKE AIRº and read its value displayed on the
hand±held tester.
Temperature value: ±40
C (±40
F)
OKREPAIR OR REPLACE HARNESS OR CONNECTOR
NG
CHECK AND REPLACE ECM (See page 01±32)

A18294
THAE2
ECM Connector
E13
A65743
THAE2
ECM Connector
E13
A54396
A6
Wire Harness SideMass Air Flow Meter Connector E2
THA
05±198
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
When not using hand±held tester:
1INSPECT ECM(THA VOLTAGE)
(a)Turn the ignition switch ON.
(b)Measure the voltage between terminals THA and E2 of the E13 ECM connector.
Voltage:
Intake air temp.Voltage
20
C (68
F)0.5 to 3.4 V
60
C (140
F)0.2 to 1.0 V
OKCHECK FOR INTERMITTENT PROBLEMS
(See page 05±149)
NG
2INSPECT MASS AIR FLOW METER (See page 10±20)
NGREPLACE MASS AIR FLOW METER
OK
3CHECK HARNESS AND CONNECTOR(ECM ± MASS AIR FLOW METER)
(a)Disconnect the E13 ECM connector.
(b)Disconnect the mass air flow meter connector.
(c)Check for continuity between the wire harness side con- nector.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
THA (E13±20) ± THA (A6±4)ContinuityE2 (E13±28) ± E2 (A6±5)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
THA (E13±20) or THA (A6±4) ± Body groundContinuity
NGREPAIR OR REPLACE HARNESS OR CONNECTOR
OK
CHECK AND REPLACE ECM
(See page 01±32)

 


AB B+
Power Transistor
Platinum Hot Wire
(Heater)
Output
Voltage
Temperature
sensor
Platinum Hot Wire (Heater)
Temperature sensor
A53295
05±186
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0100/31 MASS OR VOLUME AIR FLOW CIRCUIT
DTC P0102/31 MASS OR VOLUME AIR FLOW CIRCUIT
LOW INPUT
DTC P0103/31 MASS OR VOLUME AIR FLOW CIRCUIT
HIGH INPUT
CIRCUIT DESCRIPTION
The mass air flow meter uses a platinum hot wire. The hot wire mass air flow meter consists of a platinum
hot wire, a temperature sensor and a control circuit installed in a plastic housing. The hot wire mass air flow
meter works on the principle that the hot wire and temperature sensor located in the intake air bypass of the
housing detect any changes in the intake air temperature.
The hot wire is maintained at the set temperature by controlling the current flow through the hot wire. This
current flow is then measured as the output voltage of the mass air flow meter.
The circuit is constructed so that the platinum hot wire and temperature sensor provide a bridge circuit, with
the power transistor controlled so that the potential of A and B remains equal to maintain the set temperature.
DTC No.DTC Detection ConditionTrouble Area
P0100/31Open or short in mass air flow meter circuit with engine speed
4,000 rpm or less for more than 3 sec.
Ohti ifltiit
P0102/31Open in mass air flow meter circuit with engine speed 4,000
rpm or less for more than 3 sec.
Open or short in mass air flow meter circuit

Mass air flow meter


ECM
P0103/31Short in mass air flow meter circuit with engine speed 4,000
rpm or less for more than 3 sec. (+B circuit)
ECM
HINT:
After confirming DTC ºP0100/31, P0102/31 or P0103/31º, use the hand±held tester to confirm the mass air
flow ratio in the ºDIAGNOSIS / OBD/MOBD / DATA LIST / ALLº.
Air Flow Value (gm/s)Malfunction
Approx. 0.0
Mass air flow meter power source circuit open

VG circuit open or short
271.0 or more
E2G circuit open
05C6U±01

A76863
B±Y
Battery FL MAINEngine Room R/B No. 4
G EFI Relay
A6
Mass Air Flow MeterMREL
B±G 4B 1
W±BB±W 53
2
1
32
E128
E9ECM
EFI No. 1
EC 4A 1
Engine Room
J/B No. 4 1A 1
B±G 1 2
EFI 1
Engine Room
R/B No. 1 and
Engine Room
J/B No.14
4
44
4
4
2
1 W±B
B±R
B±RGR
GRIE1 2
EVG 24
E12VG
L±Y 1
3
2 EA112
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
05±187
AVENSIS REPAIR MANUAL (RM1018E)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
Read freeze frame data using the hand±held tester. Freeze frame data records the engine conditions when
a 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 mal-
function.