fuel TOYOTA AVALON 2001 Service Owner's Manual
[x] Cancel search | Manufacturer: TOYOTA, Model Year: 2001, Model line: AVALON, Model: TOYOTA AVALON 2001Pages: 1897, PDF Size: 26.61 MB
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
Page 922 of 1897
P24296
ECM
Throttle Position
Sensor
VC
VTA
E2
S05019A09773
ECM
1
3
22
23
185 V
VC
VTA1
E2 L-R
LG
W Throttle Position Sensor
E5 E5 E5 DI-38
- DIAGNOSTICSENGINE
194 Author: Date:
2001 AVALON (RM808U)
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 approximately 0.7 V is applied to ter-
minal VTA of the ECM. The voltage applied to terminals VTA of
the ECM increases in proportion to the opening angle of the
throttle valve and becomes approximately 2.7 - 5.2 V when the
throttle valve is fully opened. The ECM judges the vehicle driv-
ing conditions from these signals input from terminals VTA and
uses them as one of the conditions for deciding 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:
(a) VTA
0.1 V
(b) VTA
4.9 V
Open or short in throttle position sensor circuit
Throttle position sensor
ECM
HINT:
After confirming DTC P0120, use the OBD II scan tool or TOYOTA hand-held tester to confirm the throttle
valve opening percentage and closed throttle position switch condition.
Throttle valve opening position expressed as percentageTblAThrottle valve fully closedThrottle valve fully openTrouble Area
0 %0 %VC circuit open
VTA circuit open or short
Approx. 100 %Approx. 100 %E2 circuit open
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:
If DTCs P0110, P0115 and P0120 are output simultaneously, E2 (sensor ground) bay be open.
DI6T1-01
Page 923 of 1897
FI7052
A00437
1 ON
BE6653
S05338
(+)
(-)
- DIAGNOSTICSENGINE
DI-39
195 Author: Date:
2001 AVALON (RM808U)
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 throttle valve
opening percentage.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand-held tes-
ter 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 throttle valve opening percentage.
OK:
Throttle ValveThrottle valve opening position
expressed as percentage
Fully openApprox. 75 %
Fully closedApprox. 10 %
OK Check for intermittent problems
(See page DI-3).
NG
2 Check voltage between terminal 1 of wire harness side connector and body
ground.
PREPARATION:
(a) Disconnect the throttle position sensor connector.
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal 1 (VC) of the wire har-
ness side connector and body ground.
OK:
Voltage: 4.5 - 5.5 V
NG Go to step 5.
OK
3 Check throttle position sensor (See page SF-33).
Page 926 of 1897
DI-42
- DIAGNOSTICSENGINE
198 Author: Date:
2001 AVALON (RM808U)
DTC P0121 Throttle/Pedal Position Sensor/Switch ºAº
Circuit Range/Performance Problem
CIRCUIT DESCRIPTION
Refer to DTC P0120 on page DI-38.
DTC No.DTC Detecting ConditionTrouble Area
P0121
After vehicle speed has been exceeded 30 km/h (19 mph)
even once, output value of throttle position sensor is out of
applicable range while vehicle speed between 30 km/h (19
mph) and 0 km/h (0 mph)
Throttle position sensor
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 P0121) being output?
YES Go to relevant DTC chart (See page DI-14).
NO
Replace throttle position sensor.
DI07L-09
Page 927 of 1897
A00477
Atmosphere
Cover
Exhaust GasPlatinum
Electrode
Solid Electrolyte
(Zirconia Element)
Platinum
Electrode
Heater
A/F Sensor Voltage
Air-Fuel Ratio
(V)
2.6 4.0
3.8
3.6
3.4
3.2
3.0
2.8
2.4
12 13 14 15 16 17 18
Coating (Ceramic)
ECM Monitored
19
Housing
- DIAGNOSTICSENGINE
DI-43
199 Author: Date:
2001 AVALON (RM808U)
DTC P0125 Insufficient Coolant Temp. for Closed Loop
Fuel Control
CIRCUIT DESCRIPTION
To obtain a high purification rate for the CO, HC and NOx components of the exhaust gas, a three-way cata-
lytic converter is used, but for the most efficient use of the three-way catalytic converter, the air-fuel ratio
must be precisely controlled so that it is always close to the stoichiometric air-fuel ratio.
The A/F sensor has the characteristic that provides output voltage* approximately proportional to the exist-
ing air-fuel ratio. The A/F sensor output voltage* is used to provide feedback for the ECM to control the air-
fuel ratio.
By the A/F sensor output, the ECM can determine the deviation amount from the stoichiometric air-fuel ratio
and control the proper injection time immediately. If the A/F sensor is malfunctioning, ECM is unable to per-
form accurate air-fuel ratio control.
The A/F sensor is equipped with a heater which heats the zirconia element. The heater is controlled by the
ECM. When the intake air volume is low (the temp. of the exhaust gas is low), current flows to the heater
to heat the sensor for accurate oxygen concentration detection.
*: The voltage value changes at the inside of the ECM only.
DTC No.DTC Detecting ConditionTrouble Area
P0125
After engine is warmed up, A/F sensor output* does not
change when conditions (a), (b), (c) and (d) continue for at
least 1.5 min:
*: Output value changes at inside of the ECM only
(a) Engine speed: 1,500 rpm or more
(b) Vehicle speed: 40 - 100 km/h (25 - 62 mph)
(c) Throttle valve is not fully closed
(d) 140 sec. or more after starting engineOpen or short in A/F sensor (bank 1, 2 sensor 1) circuit
A/F sensor (bank 1, 2 sensor 1)
Air inducation system
Fuel pressure
Injector
Gas leakage on exhaust sytem
ECM
HINT:
After confirming DTC P0125, use the OBD II scan tool or TOYOTA hand-held tester to confirm voltage
output of the A/F sensor (bank 1, 2 sensor 1) from the CURRENT DATA.
The ECM controls the voltage of the AFR+, AFL+, AFR- and AFL- terminals of the ECM to the fixed
voltage. Therefore, it is impossible to confirm the A/F sensor output voltage without the OBDII scan
tool or TOYOTA hand-held tester.
DI07M-14
Page 928 of 1897
A11670
HTS
E03 AFR+
3.3 VECM
to Analog-Digital
Converter
to Analog-Digital
Converter
AFR-
AFL+ HAFR
3.3 V3.0 V
AFL-
OXSHAFL
3.0 VE04
E05
E1 E79
8 4
213
1220 11 E5
E5
E5
E5
E5
E5
E7
L-O
LG
B
B-R
L
B-W
BR
B-RB-R
LG
B B-W
B-W
B-W
B-W
B-W
BR
BR B From
Battery
From Terminal
MREL of ECMA/F Sensor
(Bank 1
Sensor 1)
J5 J/C
J7 J/CA/F Sensor
(Bank 2
Sensor 1)
Heated
Oxygen
Sensor
(Bank 1
Sensor 2)2
3
41
2
3
41
2
3
41 23
5
1
23
5
1 A/F Relay
EFI Relay Engine Room J/B
16
19
IK28 16
IK2 IK2II2
EC
1021
IK2
II2
EB
A
A
A12
13
9
2B
4 2B 2B2B
4 2FA/F
EFI
No.2 2
2GEFI
No.1
W-B
ED
BR
BR
BRBR B
B DI-44
- DIAGNOSTICSENGINE
200 Author: Date:
2001 AVALON (RM808U)
OBD II scan tool (excluding TOYOTA hand-held tester) displays the one fifth of the A/F sensor output
voltage which is displayed on the TOYOTA hand-held tester.
WIRING DIAGRAM
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.
Page 929 of 1897
- DIAGNOSTICSENGINE
DI-45
201 Author: Date:
2001 AVALON (RM808U)
1 Are there any other codes (besides DTC P0125) being output?
YES Go to relevant DTC chart (See page DI-14).
NO
2 Connect the OBD II scan tool or TOYOTA hand-held tester, and read value for
voltage output of A/F sensor (bank 1, 2 sensor 1).
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(b) Warm up the A/F sensor with the engine speed at 2,500 rpm for approx. 90 sec.
CHECK:
Read the voltage value of the A/F sensor on the screen of OBDII scan tool or TOYOTA hand-held tester
when you perform all the following conditions.
HINT:
The voltage of the AFR+ or AFL+ terminal of the ECM is fixed at 3.3 V and the voltage of the AFR- or AFL-
terminal is fixed at 3.0 V. Therefore, it is impossible to check the A/F sensor output voltage at the terminals
(AFR+, AFL+/AFR-, AFL-) of the ECM.
OK:
ConditionA/F Sensor Voltage Value
Engine idling
Engine racing Not remains at 3.30 V (0.660 V*)
Not remains at38V(076V*) or moreDriving at engine speed 1,500 rpm or more and vehicle
speed 40 km/h (25 mph) or more, and operate throttle valve
open and close Not remains at 3.8 V (0.76 V*) or more
Not remains at 2.8 V (0.56 V*) or less
*: When you use OBD II scan tool (excluding TOYOTA hand-held tester)
HINT:
During fuel enrichment, there is a case that the output voltage of the A/F sensor is below 2.8 V (0.56
V*), it is normal.
During fuel cut, there is a case that the output voltage of the A/F sensor is above 3.8 V (0.76 V*), it
is normal.
If the output voltage of the A/F sensor remains at 3.30 V (0.660 V*) even after performing all the above
conditions, the A/F sensor circuit may be open.
If the output voltage of the A/F sensor remains at 3.8 V (0.76 V*) or more, or 2.8 V (0.56 V*) or less
even after performing all the above conditions, the A/F sensor circuit may be short.
*: When you use the OBD II scan tool (excluding TOYOTA hand-held tester).
OK Go to step 9.
NG
Page 930 of 1897
DI-46
- DIAGNOSTICSENGINE
202 Author: Date:
2001 AVALON (RM808U)
3 Check for open and short in harness and connector between ECM and A/F sen-
sor (bank 1, 2 sensor 1) (See page IN-30).
NG Repair or replace harness or connector.
OK
4 Check resistance of A/F sensor heater (bank 1, 2 sensor 1) (See page SF-79).
NG Replace A/F sensor.
OK
5 Check air induction system (See page SF-1).
NG Repair or replace.
OK
6 Check fuel pressure (See page SF-6).
NG Check and repair fuel pump, pressure regulator,
fuel pipe line and filter (See page SF-1).
OK
7 Check injector injection (See page SF-23).
NG Replace injector.
OK
Page 931 of 1897
- DIAGNOSTICSENGINE
DI-47
203 Author: Date:
2001 AVALON (RM808U)
8 Check gas leakage on exhaust system.
NG Repair or replace
OK
Replace A/F sensor (bank 1, 2 sensor 1).
9 Perform confirmation driving pattern (See page DI-106).
Go
10 Is there DTC P0125 being output again?
YES Check and replace ECM (See page IN-30).
NO
11 Did vehicle runs out of fuel in past?
NO Check for intermittent problems
(See page DI-3).
YES
DTC P0125 is caused by running out of fuel.
Page 932 of 1897
DI-48
- DIAGNOSTICSENGINE
204 Author: Date:
2001 AVALON (RM808U)
DTC P0128 Thermostat Malfunction
CIRCUIT DESCRIPTION
If the water temperature becomes 75°C (167°F) or more, it is abnormal.
If not due to the thermostat malfunction, it is abnormal.
DTC No.DTC Detecting ConditionTrouble Area
P0128
Condition (a), (b) or (c):
(a) After starting engine at 20°C (68°F)
(b) After engine is warmed up
(c) THW < 75°C (167°F)Thermostat
Cooling system
Engine coolant temp. sensor
ECM
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 Check thermostat (See page CO-1 1).
NG Replace thermostat.
YES
2 Are there any other codes (besides DTC P0128) being output?
YES Go to relevant DTC chart (See page DI-14).
NG
Check and replace ECM (See page IN-30).
DI6T2-01