TOYOTA AVENSIS 2005 Service Repair Manual

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.

A54396
+B (+)
Wire Harness Side
Mass Air Flow Meter ConnectorA6
05±188
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
When using hand±held tester:
1READ VALUE OF HAND±HELD TESTER(MASS AIR FLOW RATE)
(a)Connect the hand±held tester to the DLC3.
(b)Start the engine.
(c)Push the hand±held tester main switch ON.
(d)Select the item ºDIAGNOSIS / OBD/MOBD / DATA LIST / ALL / MAFº and read its value displayed on the hand±held tester.
Result:
Air flow rate (gm/s)Proceed to
0.0A
271.0 or moreB
1  Mass Air Flow Rate 270.0 or more (*1)C
*1: The value must be changed when the throttle valve is opened or closed.
BGo to step 6
CCHECK FOR INTERMITTENT PROBLEMS(See page 05±149)
A
2 INSPECT MASS AIR FLOW METER(POWER SOURCE)
(a) Turn the ignition switch ON.
(b) Disconnect the mass air flow meter connector.
(c) Measure the voltage between the terminal of the wire har- ness side connector and the body ground.
Standard:
Symbols (Terminal No.)Specified condition
+B (A6±1) ± Body ground9 to 14 V
NG Go to step 5
OK

A18294
VG (+)EVG (±)
E12
ECM Connector
A54396
VG
Wire Harness Side
Mass Air Flow Meter ConnectorE2G
A6
A65745
VG
EVG
E12
ECM Connector
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±189
AVENSIS REPAIR MANUAL (RM1018E)
3INSPECT ECM(VG VOLTAGE)
(a)Start the engine.
(b)Measure the voltage between the terminals of the E12
ECM connector.
HINT:
The shift position should be P or N and the A/C switch should
be turned OFF. Standard:
Symbols (Terminal No.)ConditionSpecified condition
VG (E12±24) ±
EVG (E12±32)Engine is idling0.5 to 3.0 V
OKCHECK AND REPLACE ECM(See page 01±32)
NG
4 CHECK HARNESS AND CONNECTOR(MASS AIR FLOW METER ± ECM)
(a) Disconnect the mass air flow meter connector.
(b) Disconnect the E12 ECM connector.
(c) Check for continuity between the wire harness side con- nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
VG (A6±3) ± VG (E12±24)ContinuityE2G (A6±2) ± EVG (E12±32)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
VG (A6±3) or VG (E12±24) ± Body groundNo continuity
NG REPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE MASS AIR FLOW METER

A66053
Engine Room R/B No.4EFI Relay



A79066
Engine Room R/B No.4EFI No.1 Fuse
1
2
A54396Mass Air Flow Meter Connector
Wire Harness Side
+B
A6
A18294
EVG
ECM Connector E12
05±190
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
5CHECK HARNESS AND CONNECTOR(MASS AIR FLOW METER ± EFI RELAY)
(a)Remove the EFI relay from the engine room R/B No.4.
(b)Remove the EFI No.1 fuse from the engine room R/B No.4.
(c)Disconnect the mass air flow meter connector.
(d)Check for continuity between the wire harness side con- nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
EFI relay (3) ± EFI No.1 fuse (1)ContinuityEFI No.1 fuse (2) ± +B (A6±1)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
EFI relay (3) or EFI No.1 fuse (1) ± Body groundNocontinuityEFI No.1 fuse (2) or +B (A6±1) ± Body groundNo continuity
NOTICE:
Do not insert the tester leads hard in the procedure (c), the
holder may be damaged.
NGREPAIR OR REPLACE HARNESS OR CONNECTOR
OK
CHECK FOR ECM POWER SOURCE CIRCUIT (See page 05±257)
6 INSPECT ECM(SENSOR GROUND)
(a) Check for continuity between the terminal of the E12 ECM connector and the body ground.
Standard:
Symbols (Terminal No.)Specified condition
EVG (E12±32) ± Body groundContinuity
NG CHECK AND REPLACE ECM (See page 01±32)
OK

A54396
VG
Wire Harness Side
Mass Air Flow Meter ConnectorE2G
A6
A65745
VG
EVG
E12
ECM Connector
A18294
VG (+)EVG (±)
E12
ECM Connector
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±191
AVENSIS REPAIR MANUAL (RM1018E)
7CHECK HARNESS AND CONNECTOR(MASS AIR FLOW METER ± ECM)
(a)Disconnect the mass air flow meter connector.
(b)Disconnect the E12 ECM connector.
(c)Check for continuity between the wire harness side con-
nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
VG (A6±3) ± VG (E12±24)ContinuityE2G (A6±2) ± EVG (E12±32)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
VG (A6±3)or VG (E12±24) ± Body groundNo continuity
NGREPAIR OR REPLACE HARNESS OR CONNECTOR
OK
REPLACE MASS AIR FLOW METER
When not using hand±held tester:
1INSPECT ECM(VG VOLTAGE)
(a)Start the engine.
(b)Measure the voltage between the terminals of the E12 ECM connector.
HINT:
The shift position should be P or N and the A/C switch should
be turned OFF. Standard:
Symbols (Terminal No.)ConditionSpecified condition
VG (E12±24) ±
EVG (E12±32)Engine is idling0.5 to 3.0 V
OKCHECK AND REPLACE ECM(See page 01±32)
NG

A54396
+B (+) Wire Harness Side
Mass Air Flow Meter ConnectorA6
A54396
VG Wire Harness Side
Mass Air Flow Meter ConnectorE2G A6
A65745
VGEVG
E12
ECM Connector
05±192
± DIAGNOSTICSSFI SYSTEM (1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
2 INSPECT MASS AIR FLOW METER(POWER SOURCE)
(a) Turn the ignition switch ON.
(b) Disconnect the mass air flow meter connector.
(c) Measure the voltage between the terminal of the wire har-
ness side connector and the body ground.
Standard:
Symbols (Terminal No.)Specified condition
+B (A6±1) ± Body ground9 to 14 V
NG Go to step 4
OK
3 CHECK HARNESS AND CONNECTOR(MASS AIR FLOW METER ± ECM)
(a) Disconnect the mass air flow meter connector.
(b) Disconnect the E12 ECM connector.
(c) Check for continuity between the wire harness side con-
nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
VG (A6±3) ± VG (E12±24)ContinuityE2G (A6±2) ± EVG (E12±32)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
VG (A6±3) or VG (E12±24) ± Body groundNo continuity
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
REPLACE MASS AIR FLOW METER

A66053
Engine Room R/B No.4EFI Relay



A79066
Engine Room R/B No.4EFI No.1 Fuse
1
2
A54396Mass Air Flow Meter Connector
Wire Harness Side
+B
A6
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
05±193
AVENSIS REPAIR MANUAL (RM1018E)
4CHECK HARNESS AND CONNECTOR(MASS AIR FLOW METER ± EFI RELAY)
(a)Remove the EFI relay from the engine room R/B No.4.
(b)Remove the EFI No.1 fuse from the engine room R/B
No.4.
(c)Disconnect the mass air flow meter connector.
(d)Check for continuity between the wire harness side con- nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
EFI relay (3) ± EFI No.1 fuse (1)ContinuityEFI No.1 fuse (2) ± +B (A6±1)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
EFI relay (3) or EFI No.1 fuse (1) ± Body groundNocontinuityEFI No.1 fuse (2) or +B (A6±1) ± Body groundNo continuity
NOTICE:
Do not insert the tester leads hard in the procedure (c), the
holder may be damaged.
NGREPAIR OR REPLACE HARNESS OR CONNECTOR
OK
CHECK FOR ECM POWER SOURCE CIRCUIT (See page 05±257)

B62793
Reference (Bank 1 Sensor 1 System Drawing)A/F Sensor
A/F Relay
Heater
Sensor A1A+ HA1A
Duty
Control
ECM
From
Battery A/F Fuse
A1A±
MREL
05±182
±
DIAGNOSTICS SFI SYSTEM(1AZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
DTCP0031/21OXYGEN (A/F) SENSOR HEATER CONTROL CIRCUIT LOW (BANK 1 SENSOR 1)
DTCP0032/21OXYGEN (A/F) SENSOR HEATER CONTROL CIRCUIT HIGH (BANK 1 SENSOR 1)
DTCP0051/28OXYGEN (A/F) SENSOR HEATER CONTROL CIRCUIT LOW (BANK 2 SENSOR 1)
DTCP0052/28OXYGEN (A/F) SENSOR HEATER CONTROL CIRCUIT HIGH (BANK 2 SENSOR 1)
CIRCUIT DESCRIPTION
Refer to DTC P2237/21 on page 05±248.
HINT:

These DTCs are related to the air fuel raito (A/F) sensor, although the caption is the heated oxygen
sensor.

The ECM provides a pulse width modulated control circuit to adjust curre\
nt through the heater. The
heated oxygen sensor heater circuit uses a relay on the B+ side of the c\
ircuit.
DTC No.DTC Detection ConditionTrouble Area
P0031/21
P0051/28Heated current is 0.8 A or less when heater operates
(1 trip detection logic)
Open or short in heater circuit of A/F sensor

A/F sensor heater
P0032/21
P0052/28When the heater operates, heated current exceeds 19.7 A
(1 trip detection logic)
A/F relay

ECM
HINT:

Bank 1 refers to the bank that includes cylinder No.1.

Bank 2 refers to the bank that does not include cylinder No.1.

Sensor 1 refers to the sensor closest to the engine assembly.

Sensor 2 refers to the sensor farthest away from the engine assembly.
05C6T±01