2001 TOYOTA AVALON stop start

- DIAGNOSTICSCRUISE CONTROL SYSTEM
DI-559
715 Author
: Date
:
2001 AVALON (RM808U) CAN e GND
WLWB
Ignition switch ON
Cancel switch OFF10 - 16 VCAN e GND
(C15-1 e C15-16)W-L e W-BIgnition switch ON
Cancel switch ONBelow 1 V
SPD e GND
(C15 12C15 16)V-W e W-B
Engine start
Car stoppage.Below 1.5 V or
4.7 - 16 V
(C15-12 e C15-16)VW e WB
During driving (Pulse generated).3 - 7 V
IDL e GND YWB
Ignition switch ON
Throttle valve fully opened.10 - 16 VIDL e GND
(C15-13 e C15-16)Y e W-BIgnition switch ON
Throttle valve fully closed.Below 1.5 V
OD e GNDGRWB
During cruise control driving
OD switch ON.10 - 16 VOD e GND
(C15-14 e C15-16)GR e W-BDuring cruise control driving
OD switch OFF (3rd driving)Below 1 V
MO e GND PWB
During cruise control driving
ACC switch hold ON9 - 15 VMO e GND
(C15-15 e C15-16)P e W-BDuring cruise control driving
COAST switch hold ONBelow 1 V
GND e Body Ground
(C15-16 e Body Ground)W-B e Body
GroundConstantBelow 1 V

A11668
Engine Room J/B
EFI No.1
2G
2B 2A
2F2
5
1 3
2B-W
4L-O
4 2
EFI No.2 EFI Relay
From BatteryB
Mass Air
Flow Meter3
2 1
EDW-B
R-BECM
E2GVG
E2 R10
19
E5E5
From
Terminal
MREL of
ECM
DI-24
- DIAGNOSTICSENGINE
180 Author
: Date
:
2001 AVALON (RM808U)
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.
1 Connect OBD II scan tool or TOYOTA hand-held tester, and read value of mass
air flow rate.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the OBD II scan tool or TOYOTA hand-held tester main switch
ON.
(c) Start the engine.
CHECK:
Read the mass air flow rate on the OBD II scan tool or TOYOTA hand-held tester.
RESULT:
Type IType II
Mass Air Flow Rate (gm/sec.)0.0271.0 or more
Type I Go to step 2.
Type II Go to step 5.

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 engine
Cooling 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

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

A00479
Engine Speed
3,000 rpm
Idling
IG SW OFF
Warmed up
3 min. or so
CheckTime (a)(c) (d)
(b) 2,000 rpm
2 sec. 2 sec.
DI-72
- DIAGNOSTICSENGINE
228 Author
: Date
:
2001 AVALON (RM808U)
CONFIRMATION ENGINE RACING PATTERN
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(b) Start engine and warm it up with all the accessories switched OFF until the water temperature is stable.
(c) Race the engine at 2,500 - 3,000 rpm for about 3 min.
(d) When racing the engine at 3,000 rpm for 2 sec. and 2,000 rpm for 2 sec. alternately, check the wave-
form of the heated oxygen sensor (bank 1 sensor 2).
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 P0420) being output?
YES Go to relevant DTC chart (See page DI-14).
NO
2 Check gas leakage on exhaust system.
NG Repair or replace.
OK

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-138
- DIAGNOSTICSENGINE
294 Author
: Date
:
2001 AVALON (RM808U)
DTC P1656 OCV Circuit Malfunction (bank 1)
DTC P1663 OCV Circuit Malfunction (bank 2)
CIRCUIT DESCRIPTION
Refer to DTC P1349, P1354 on page DI-127.
DTC No.DTC Detecting ConditionTrouble Area
P1656
P1663Open or short in oil control valve circuit

Open or short in OCV circuit

OCV

ECM
WIRING DIAGRAM
Refer to DTC P1349, P1354 on page DI-127.
INSPECTION PROCEDURE
HINT:

If DTC P1656 dysplayed, check left bank OCV circuit.

If DTC P1663 dysplayed, check right bank OCV 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.
TOYOTA hand-held tester:
1 Check OCV circuit.
PREPARATION:
(a) Start the engine and warmed it up.
(b) Connect the TOYOTA hand-held tester and select the VVT from the ACTIVE TEST menu.
CHECK:
Check the engine speed when operate the OCV by the TOYOTA hand-held tester.
OK:
VVT system is OFF (OCV is OFF): Normal engine speed
VVT system is ON (OCV is ON): Rough idle or engine stalled
OK Check for intermittent problems
(See page DI-3).
NG
DI6TC-01

- DIAGNOSTICSENGINE
DI-141
297 Author
: Date
:
2001 AVALON (RM808U)
DTC P1780 Park/Neutral Position Switch Malfunction
CIRCUIT DESCRIPTION
The park/neutral position switch go on when the shift lever is in the N or P shift position. When it goes on,
terminal NSW of the ECM is grounded to body ground via the starter relay, thus the terminal NSW voltage
becomes 0V. When the shift lever is in the D, 2, L or R position, the park/neutral position switch goes off,
so the voltage of ECM. Terminal NSW becomes battery voltage, the voltage of the ECM internal power
source. If the shift lever is moved from the N position to the D position, this signal is used for air-fuel ratio
correction and for idle speed control (estimated control), etc.
DTC No.DTC Detecting ConditionTrouble Area
P1780
When driving under conditions (a) and (b) for 30 sec. or more
the park/neutral position switch is ON (N position): (2 trip
dt ti l i)

Short in park/neutral position switch circuit
P k/ t l iti it hP1780detection logic)
(a) Vehicle speed: 40 km/h (25 mph) or more
(b) Engine speed: 1,500 - 4,000 rpm
Park/neutral position switch

ECM
HINT:
After confirming DTC P1780, use the TOYOTA hand-held tester to confirm the PNP switch signal from the
CURRENT DATA.
WIRING DIAGRAM
Refer to DTC P1780 on page DI-199.
INSPECTION PROCEDURE
Refer to DTC P1780 on page DI-199.
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.
DI08A-09