2005 TOYOTA AVENSIS diagnostic

A66053
Engine Room R/B No.4
EFI Relay



A79070
Engine Room R/B No.4
EFI No.2 Fuse 1
2
A79114
OX+B
E2 HT
Heated Oxygen Sensor Connector Wire Harness Side
H7
OX+B
E2 HT
Heated Oxygen Sensor Connector Wire Harness Side
H17
A73939
± DIAGNOSTICSSFI SYSTEM (1ZZ±FE/3ZZ±FE)
05±51
AVENSIS REPAIR MANUAL (RM1018E)
7 CHECK HARNESS AND CONNECTOR(EFI RELAY ± HEATED OXYGEN SENSOR)
(a) Remove the EFI relay from the engine room R/BNo.4.
(b) Remove the EFI No.2 fuse from the engine room R/B
No.4.
(c) Disconnect the heated oxygen sensor 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.2 fuse (1)Continuity
Standard (Check for short):
Symbols (Terminal No.)Specified condition
EFI relay (3) or EFI No.2 fuse (1) ± Body groundNo continuity
Standard (Check for open): (Bank1 Sensor1)
Symbols (Terminal No.)Specified condition
EFI No.2 fuse (2) ± +B (H7±2)Continuity
Standard (Check for short): (Bank1 Sensor1)
Symbols (Terminal No.)Specified condition
EFI No.2 fuse (2) or +B (H7±2) ± Body groundNo continuity
Standard (Check for open): (Bank1 Sensor2)
Symbols (Terminal No.)Specified condition
EFI No.2 fuse (2) ± +B (H17±2)Continuity
Standard (Check for short): (Bank1 Sensor2)
Symbols (Terminal No.)Specified condition
EFI No.2 fuse (2) or +B (H17±2) ± Body groundNo continuity
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK

05±52
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
8CHECK WHETHER MISFIRE IS OCCURRED OR NOT BY MONITORING DTC AND DATA LIST
NGPERFORM TROUBLESHOOTING FOR MISFIRE
(See page 05±5)
OK
9CHECK AIR INDUCTION SYSTEM
(a)Check for vacuum leaks in air induction system. NGREPAIR OR REPLACE AIR INDUCTION SYSTEM
OK
10CHECK FUEL PRESSURE (See page 11±5)
(a)Check the fuel pressure (high or low pressure). NGREPAIR OR REPLACE FUEL SYSTEM
OK
11INSPECT FUEL INJECTOR ASSY(INJECTION AND VOLUME) (See page 11±8)
NGREPLACE FUEL INJECTOR ASSY
OK
12CHECK FOR EXHAUST GAS LEAK
NGREPAIR OR REPLACE EXHAUST GAS LEAKAGE POINT
OK
REPLACE HEATED OXYGEN SENSOR
13PERFORM CONFIRMATION DRIVING PATTERN (See page 05±54)
GO

±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
05±53
AVENSIS REPAIR MANUAL (RM1018E)
14READ OUTPUT DTC(DTC P0125 IS OUTPUT AGAIN)
(a)Read the DTC using the hand±held tester.
Result:
Display (DTC output)Proceed to
ºP0125º is not output againA
ºP0125º is output againB
BCHECK AND REPLACE ECM (See page 01±32)
A
15 CONFIRM IF VEHICLE HAS RUN OUT OF FUEL IN PAST
NO CHECK FOR INTERMITTENT PROBLEMS
YES
DTC IS CAUSED BY RUNNING OUT OF FUEL

A58684
ECM
5V
VC
VTA
E2 Throttle Position
Sensor
± DIAGNOSTICSSFI SYSTEM (1ZZ±FE/3ZZ±FE)
05±39
AVENSIS REPAIR MANUAL (RM1018E)
DTC P0120 THROTTLE PEDAL POSITION
SENSOR/SWITCH ºAº CIRCUIT
MALFUNCTION
CIRCUIT DESCRIPTION
The throttle position sensor is mounted in the throttle body and
detects the throttle valve opening angle.
When the throttle valve is fully closed, a voltage of approximate-
ly 0.7 V is applied to terminal VTA of the ECM. The voltage ap-
plied to terminal VTA of the ECM increases in proportion to the
opening angle of the throttle valve and becomes approximately
3.5 to 5.0 V when the throttle valve is fully opened. The ECM
judges the vehicle driving conditions from these signals input
from terminal VTA, uses them as one of the conditions for decid-
ing the air±fuel ratio correction, power increase correction and
fuel±cut control etc.
DTC No.DTC Detecting ConditionTrouble Area
P0120
Condition (a) or (b) continues for more than 5 sec.
(a) VTA is less than 0.1 V
(b) VTA is greater than 4.9 V
Open or short in throttle position sensor circuit

Throttle position sensor

ECM
HINT:
After confirming DTC ºP0120º, use the hand±held tester to confirm the throttle valve opening percentage.
Throttle valve opening position expressed as percentageTrouble AreaThrottle valve fully closedThrottle valve fully openTrouble Area
0 %0 %VC circuit open
VTA circuit open or short
Approx. 100 %Approx. 100 %E2 circuit open
05B3S±02

A79108
VCECM
VTA
E2 L±W R±W
BR T2
Throttle Position Sensor
1
3
218
E13
21
E13
28
E13 VC
E2 VTA5V
E1 05±40
± DIAGNOSTICSSFI SYSTEM (1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

Read freeze frame data using    
 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 malfunction.

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.

FI7052
Released
Depressed
VC
E2
VTAA53154Throttle Position Sensor
T2
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
05±41
AVENSIS REPAIR MANUAL (RM1018E)
1READ VALUE OF HAND±HELD TESTER(THROTTLE VALVE OPENING
PERCENTAGE)
(a)Turn the ignition switch ON.
(b)Select the item ºDIAGNOSIS / OBD/MOBD / DATA LIST
/ ALL / THROTTLE POSº and read its value displayed on
the hand±held tester.
Result:
Accelerator pedal
operatuinThrottle valve opening position expressed as percentage
Proceed to
0 %A
Released
DepressedApprox. 10 %

Approx. 75 %B
Approx. 100 %C
BCHECK FOR INTERMITTENT PROBLEMS (See page 05±5)
C Go to step 4
A
2 INSPECT THROTTLE POSITION SENSOR
(a) Disconnect the throttle position sensor connector.
(b) Measure the resistance between the terminals of the throttle position sensor.
Standard:
Symbols (Terminal No.)Throttle ValveResistance
VC (T2±1) ± E2 (T2±2)2.5 to 5.9 k

VTA (T2 3) E2 (T2 2)Fully closed0.2 to 5.7 k
VTA (T2±3) ± E2 (T2±2)Fully open2.0 to 10.2 k

NG REPLACE THROTTLE POSITION SENSOR
OK

A65159E2
VTAECM Connector
VC
E13
VC
E2
VTAA53154Throttle Position Sensor
T2
05±42
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
AVENSIS REPAIR MANUAL (RM1018E)
3CHECK HARNESS AND CONNECTOR(ECM ± THROTTLE POSITION SENSOR)
(a)Disconnect the E13 ECM connector.
(b)Measure the resistance between the terminals of the E13 ECM connector.
Standard:
Symbols (Terminal No.)Throttle valveResistance
VC (E13±18)
± E2 (E13±28)
2.5 to 5.9 k

VTA(E13±21) Fully closed0.2 to 5.7 k
VTA(E1321)
± E2 (E13±28)
Fully open2.0 to 10.2 k

(c)Check for continuity between the terminals of the E13
ECM connector.
Standard (Check for short):
Symbols (Terminal No.)Specified condition
VC (E13±18) ± Body groundNoContinuityVTA (E13±28) ± Body groundNo Continuity
NGREPAIR OR REPLACE HARNESS OR CONNECTOR
OK
CHECK AND REPLACE ECM (See page 01±32)
4 INSPECT THROTTLE POSITION SENSOR
(a) Disconnect the throttle position sensor connector.
(b) Measure the resistance between the terminals of the throttle position sensor.
Standard:
Symbols (Terminal No.)Throttle ValveResistance
VC (T2±1) ± E2 (T2±2)
2.5 to 5.9 k

VTA (T2 3) E2 (T2 2)Fully closed0.2 to 5.7 k
VTA (T2±3) ± E2 (T2±2)Fully open2.0 to 10.2 k

NG REPLACE THROTTLE POSITION SENSOR
OK

A65159E2
VTA
E13
ECM Connector
VC
23
1
A79044Throttle Position Sensor Connector
Wire Harness Side
VC
E2VTA
T2
±
DIAGNOSTICS SFI SYSTEM(1ZZ±FE/3ZZ±FE)
05±43
AVENSIS REPAIR MANUAL (RM1018E)
5CHECK HARNESS AND CONNECTOR(ECM ± THROTTLE POSITION SENSOR)
(a)Disconnect the E13 ECM connector.
(b)Disconnect the throttle position sensor connector.
(c)Check for continuity between the wire harness side con-
nectors.
Standard (Check for open):
Symbols (Terminal No.)Specified condition
VC (T2±1) ± VC (E13±18)
VTA (T2±3) ± VTA (E13±21)Continuity
E2 (T2±2) ± E2 (E13±28)
y
Standard (Check for short):
Symbols (Terminal No.)Specified condition
VC (T2±1)or VC (E13±18) ± Body groundNocontinuityVTA (T2±3)or VTA (E13±21) ± Body groundNo continuity
NGREPAIR OR REPLACE HARNESS OR CONNECTOR
OK
CHECK AND REPLACE ECM (See page 01±32)