2001 TOYOTA AVALON air condition

A11666
ECM
Vapor Pressure Sensor
2B6
P-B
VSV for EVAP
B-R
2
15 V
VC
PTNK
E1
E2
EVP1
E01
E01
TBP
3
2
Engine Room J/B
B-W
W-B
P
1
WE5
E82
17
18
7
3
E7
EFI Relay
PL-R
ID1 II215 4
5
E5
ID1 9
6 2G
4 2
53
2
1 EFI
No.1
From
Battery
20
G
VSV for Pressure
Switching ValveCCV
2
110
318
1
VSV for CCV
14
E01 L-R L-R
W WID1
ID1 II2
E5
E8 B-W
2B
2B 2FEFI
No.2
4
EDID1II1 G
B-W B-W
2
P-B
L-OFrom
Terminal
MREL of
ECM
B
B-W
- DIAGNOSTICSENGINE
DI-75
231 Author
: Date
:
2001 AVALON (RM808U)
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440 or P0442, first troubleshoot DTC
P0441, P0446, P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 or P0442 next.

Ask the customer whether, after the MIL came on, the customer found the fuel tank cap loose and tight-
ened it. Also ask the customer whether the fuel tank cap was loose when refuelling. If the fuel tank cap
was loose, it was the cause of the DTC. If the fuel tank cap was not loose or if the customer was not
sure if it was loose, troubleshoot according to the following procedure.

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.

When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the
vapor pressure sensor.

- DIAGNOSTICSENGINE
DI-81
237 Author
: Date
:
2001 AVALON (RM808U)DTC No.
DTC Detecting ConditionTrouble Area
P0441
Pressure in charcoal canister and fuel tank does not drop dur-
ing purge control (2 trip detection logic)
Vacuum hose cracks, holed blocked, damaged or discon-
nected ((1), (2), (3), (4), (5), (6), (7), (8), (9), (10) and (11) in
Fig 1)P0441
During purge cut-off, negative pressure incomming in the char-
coal canister and fuel tank will not stop. (2 trip detection logic)
Fig. 1)

Fuel tank cap incorrectly installed

Fuel tank cap cracked or damaged

Open or short in vaporpressure sensorcircuit
When VSV for pressure switching valve is ON, ECM judges
that there is no continuity between vapor pressure sensor, fuel
tank and charcoal canister (2 trip detection logic)

Open or short in vapor pressure sensor circuit

Vapor pressure sensor

Open or short in VSV circuit for EVAP

VSV for EVAP
O h t i VSV i it f CCV
P0446
When VSV for pressure switching valve is turned OFF, pres-
sure in fuel tank is maintained at atmospheric pressure (2 trip
detection logic)

Open or short in VSV circuit for CCV

VSV for CCV

Open or short in VSV circuit for pressure switching valve

VSV for pressure switching valve
When VSV for CCV is ON, pressure in charcoal canister and
fuel tank is maintained at atmospheric pressure (2 trip detec-
tion logic)
g

Fuel tank cracked, holed or damaged

Charcoal canister cracked, holed or damaged

Fuel tank over fill check valve cracked damaged

ECM
WIRING DIAGRAM
Refer to DTC P0440 or P0442 on page DI-74.
INSPECTION PROCEDURE
HINT:

If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440 or P0442,first troubleshoot DTC
P0441, P0446, P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 or P0442 next.

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.

When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the
vapor pressure sensor.
TOYOTA hand-held tester:
1 Check whether hose close to fuel tank have been modified, and check whether
there are signs of any accident near fuel tank or charcoal canister (See page
DI-74, step 1).
NG Repair or replace.
OK
2 Check that fuel tank cap is TOYOTA genuine parts (See page DI-74, step 2).
NG Replace to TOYOTA genuine parts.

DI-98
- DIAGNOSTICSENGINE
254 Author
: Date
:
2001 AVALON (RM808U)
WIRING DIAGRAM
Refer to DTC P0440 or P0442 on page DI-74.
INSPECTION PROCEDURE
HINT:

If DTC P0441, P0446, P0450 or P0451 is output after DTC P0440 or P0442, first trouble shoot DTC
P0441, P0446 P0450 or P0451. If no malfunction is detected, troubleshoot DTC P0440 or P0442 next.

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.

When the ENGINE RUN TIME in the freeze frame data is less than 200 seconds, carefully check the
VSV for EVAP, charcoal canister and vapor pressure sensor.
1 Check voltage between terminals VC and E2 of ECM connector (See page
DI-74, step 9).
NG Check and replace ECM (See page IN-30).
OK
2 Check voltage between terminals PTNK and E2 of ECM connectors (See page
DI-74, step 10).
OK Check and replace ECM (See page IN-30).
NG
3 Check for open and short in harness and connector between vapor pressure sen-
sor
and ECM (See page IN-30).
NG Repair or replace harness or connector.
OK
Replace vapor pressure sensor.

A00022
4-Pulse
Engine
ECM
Multi Display From
Speed Sensor4-Pulse
ABS Actuator
& ECU
A11086
Multi Display
18
M3 E73F V-W V-WECM
SPD5 V
122
3C 1J/B No.3
- DIAGNOSTICSENGINE
DI-99
255 Author
: Date
:
2001 AVALON (RM808U)
DTC P0500 Vehicle Speed Sensor Malfunction
CIRCUIT DESCRIPTION
This sensor is mounted in the combination meter. It contains a magnet which is rotated by the speedometer
cable.
Turning the reed switch ON and OFF 4 times for every revolution of the speedometer.
It is then transmitted to the Engine ECM. The Engine ECM determines the vehicle speed based on the fre-
quency of these pulse signals.
DTC No.DTC Detecting ConditionTrouble Area
No vehicle speed sensor signal to Engine & ECT ECU under
Combination meter
P0500/61
No vehicle speed sensor signal to Engine & ECT ECU under
th f ll i diti (2 t i d t ti l i )

Combination meter
Ohtid iitP0500/61the following conditions: (2 trip detection logic)
Open or short in speed sensor circuitg( g)
Vehicle is being driven
ECM
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.
DI082-09

P01559
Throttle Valve
From
Air
Cleaner
Signal
ECM
ValveIAC Valve
To Cylinders Intake Air Chamber
A11664
From Battery2G1 2
4 EFI
No.1EFI Relay
1 23
52A
2B 2F
J7
J/C IAC Valve
G-B
BR
21
3E4ECM
RSO
E01
EC26
A B-W
L-O
BRA
4EFI
No.2
B
W-B
EDEngine Room J/B
EBA
From
Terminal
MREL of
ECM
DI-102
- DIAGNOSTICSENGINE
258 Author
: Date
:
2001 AVALON (RM808U)
DTC P0505 Idle Control System Malfunction
CIRCUIT DESCRIPTION
The rotary solenoid type IAC valve is located in front of the in-
take air chamber and intake air bypassing the throttle valve is
directed to the IAC valve through a passage.
In this way the intake air volume bypassing the throttle valve is
regulated, controlling the engine speed.
The ECM operates only the IAC valve to perform idle-up and
provide feedback for the target idling speed.
DTC No.DTC Detecting ConditionTrouble Area
P0505Idle speed continues to vary greatly from the target speed (2
trip detection logic)

Open or short in IAC valve circuit

IAC valve is stuck or closed

Open or short in A/C signal circuit

Air induction system

ECM
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.
DI083-09

DI-106
- DIAGNOSTICSENGINE
262 Author
: Date
:
2001 AVALON (RM808U)
DTC P1130 A/F Sensor Circuit Range/Performance Mal-
function (Bank 1 Sensor 1)
DTC P1150 A/F Sensor Circuit Range/Performance Mal-
function (Bank 2 Sensor 1)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI-43.
DTC No.DTC Detecting ConditionTrouble Area
Voltage output* of A/F sensor remains at 3.8 V or more, or 2.8
V or less, during engine running after the engine is warmed up
(2 trip detection logic)
*: Output value changes at inside of ECM only

Open or short in A/F sensor circuit

A/F sensor
P1130
P1150Voltage output* of A/F sensor does not change from 3.30 V,
during engine running after the engine is warmed up (2 trip
detection logic)
*: Output value changes at the inside of ECM only
Air induction system

Fuel pressure

Injector

ECM
Open or short in A/F sensor circuit (2 trip detection logic)
HINT:

After confirming DTC P1130, use the OBD II scan tool or TOYOTA hand-held tester to confirm voltage
output of A/F sensor (AFS B1 S1/O2S B1 S1) from the CURRENT DATA.

The A/F sensor's output voltage and the short-term fuel trim value can be read using the OBD II scan
tool or TOYOTA hand-held tester.

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.

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
Refer to DTC P0125 on page DI-43.
DI2H7-03

A00364
Vehicle Speed
60 - 120 km/h
(38 - 75 mph)
Idling
IG SW OFF
3 - 5 min.
Time
(a) (b)(c)(d)
- DIAGNOSTICSENGINE
DI-107
263 Author
: Date
:
2001 AVALON (RM808U)
CONFIRMATION DRIVING PATTERN
(a) Connect the TOYOTA hand-held tester to the DLC3.
(b) Switch the TOYOTA hand-held tester from the normal mode to the check mode (See page DI-3).
(c) Start the engine and warm it up with all the accessory switches OFF.
(d) Drive the vehicle at 60 - 120 km/h (38 - 75 mph) and engine speed at 1,400 - 3,200 rpm for 3 - 5 min.
HINT:
If a malfunction exists, the MIL will light up during step (d).
NOTICE:
If the conditions in this test are not strictly followed, detection of the malfunction will not be possible.
If you do not have a TOYOTA hand-held tester, turn the ignition switch OFF after performing steps
(c) and (d), then perform steps (c) and (d) again.
INSPECTION PROCEDURE
HINT:

If DTC P1130 is displayed, check Bank 1 Sensor 1 circuit.

If DTC P1150 is displayed, check Bank 2 Sensor 1 circuit.

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 P1130, P1150) being output?
YES Go to relevant DTC chart (See page DI-14).
NO

DI-108
- DIAGNOSTICSENGINE
264 Author
: Date
:
2001 AVALON (RM808U)
2 Check output voltage of A/F sensor.
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 normally.

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
3 Check for open and short in harness and connector between ECM and A/F sen-
sor (See page IN-30).
NG Repair or replace harness or connector.
OK