air conditioning TOYOTA AVALON 2001 Service Owners Manual

AC2FV-01
- AIR CONDITIONINGTROUBLESHOOTING (Manual A/C)
AC-15
1937 Author
: Date
:
2001 AVALON (RM808U)
TROUBLESHOOTING (Manual A/C)
PROBLEM SYMPTOMS TABLE
Use the table below to help you find the cause of the problem. The numbers indicate the priority of the likely
cause of the problem. Check each part in order If necessary , replace these parts.
SymptomSuspect AreaSee page
No blower operation
2. HTR Fuse
3. Heater main relay
4. Blower motor
5. Blower resistor
6. Blower speed control switch
7. Wire harness-
AC-68
AC-56
AC-57
AC-83
-
No blower control
1. Blower motor
2. Blower resistor
3. Blower speed control switch
4. Wire harnessAC-56
AC-57
AC-83
-
No air temperature control1. Engine coolant volume
2. Heater control assembly-
AC-80
No compressor operation
1. Refrigerant volume
2. A.C Fuse
3. Magnetic clutch
4. Compressor lock sensor
5. Compressor
6. Pressure switch
7. Heater main relay
8. Blower speed control switch
9. A/C switch
10.A/C amplifier
11. Evaporator temp. sensor
12.Wire harnessAC-3
-
AC-42
AC-42
AC-42
AC-65
AC-68
AC-83
AC-83
AC-77
AC-64
-
No cool air comes out
1. Refrigerant volume
2. Refrigerant pressure
3. Drive belt
4. Magnetic clutch
5. Compressor lock sensor
6. Pressure switch
7. Evaporator temp. sensor
8. A/C switch
9. A/C amplifier
10.Heater control assembly
11. Wire harnessAC-3
AC-3
AC-17
AC-42
AC-42
AC-65
AC-64
AC-83
AC-77
AC-80
-
No engine idle-up when A/C switch ON
1. A/C amplifier
2. Idle control system
3. Wire harnessAC-77
DI-102
-
No air inlet control
1. Air inlet servomotor
2. Heater control assembly
3. Wire harnessAC-39
AC-80
-
No mode control
1. Air outlet servomotor
2. Heater control assembly
3. Wire harnessAC-60
AC-80
-

AC-16
- AIR CONDITIONINGTROUBLESHOOTING (Manual A/C)
1938 Author
: Date
:
2001 AVALON (RM808U) Blinking of A/C indicator
1. Compressor
2. Drive belt
3. Compressor lock sensor
4. A/C amplifierAC-42
AC-17
AC-42
AC-77
Brightness does not change when light control switch is turned1. Headlight and taillight system
2. Heater control assemblyBE-19
AC-80

F07887
TOYOTA hand-held tester
DLC3
BR3904
0.13 sec. 0.13 sec.
ON
OFF
- DIAGNOSTICSAUTOMATIC TRANSAXLE
DI-163
319 Author
: Date
:
2001 AVALON (RM808U)
3. INSPECT DIAGNOSIS (CHECK MODE)
HINT:
TOYOTA hand- held tester only: Compared to the normal
mode, the check mode has high sensing ability to detect mal-
functions. Furthermore, the same diagnostic items which are
detected in Normal mode can also be detected in Check mode.
(a) Check the DTC.
(1) Check the initial conditions.

Battery positive voltage 11 V or more

Throttle valve fully closed

Transaxle in P position

Air conditioning switched OFF
(2) Turn the ignition switch OFF
(3) Prepare a TOYOTA hand-held tester
(4) Connect the TOYOTA hand-held tester to DLC3 at
the lower of the instrument panel.
(5) Turn the ignition switch ON and switch the TOYOTA
hand-held tester ON.
(6) Switch the TOYOTA hand-held tester from Normal
mode to Check mode (Check that the MIL flashes).
(7) Start the engine (MIL goes out after the engine
starts).
(8) Simulate the conditions of the malfunction de-
scribed by the customer.
NOTICE:
Leave the ignition switch ON until you have checked the
DTCs, etc..
(9) After simulating the malfunction conditions, use the
TOYOTA hand-held tester diagnosis selector to
check the DTCs and freeze frame data, etc.
HINT:
Take care not to turn the ignition switch OFF, as turning it off
switches the diagnosis system from Check mode to Normal
mode, so all DTCs, etc. are erased.
(10) After checking the DTC, inspect the applicable cir-
cuit.

EM0CF-02
EM-12
- ENGINE MECHANICALIDLE SPEED
996 Author
: Date
:
2001 AVALON (RM808U)
IDLE SPEED
INSPECTION
1. INITIAL CONDITIONS
(a) Engine at normal operating temperature
(b) Air cleaner installed
(c) All pipes and hoses of air induction system connected
(d) All accessories switched OFF
(e) All vacuum lines properly connected
(f) SFI system wiring connectors fully plugged
(g) Ignition timing check correctly
(h) Transmission in neutral position
(i) Air conditioning switched OFF
2. CONNECT TOYOTA HAND-HELD TESTER OR OBDII SCAN TOOL (See page EM-10)
3. INSPECT IDLE SPEED
(a) Race the engine speed at 2,500 rpm for approx. 90 seconds.
(b) Check the idle speed.
Idle speed: 650 ± 50 rpm
If the idle speed is not as specified, check the IAC valve and air intake system.
4. DISCONNECT TOYOTA HAND-HELD TESTER OR OBDII SCAN TOOL

IN05Y-17
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN-19
19 Author
: Date
:
2001 AVALON (RM808U)
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the AVALON. In general, the ECU controlled system
is considered to be a very intricate system requiring a high level of technical knowledge and expert skill to
troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, troubleshooting of
these systems is not complex. If you have adequate understanding of the system and a basic knowledge
of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem. This
manual is designed through emphasis of the above standpoint to help service technicians perform accurate
and effective troubleshooting, and is compiled for the following major ECU controlled systems:
The troubleshooting procedure and how to make use of it are described on the following pages.
SystemPage
1. EngineDI-1
2. Automatic TransaxleDI-158
3. Anti-Lock Brake System With Electronic Brake Force Distribution (EBD)DI-210
4. ABS With EBD & BA & TRAC & VSC SystemDI-250
5. Supplemental Restraint SystemDI-347
6. Power Seat Control System (w/ Driving position memory)DI-488
7. Theft Deterrent SystemDI-517
8. Cruise Control SystemDI-549
9. Engine Immobilizer SystemDI-597
10.Body Control SystemDI-615
11. Driver Door Control SystemDI-676
12.Passenger Door Control SystemDI-700
13.Multiplex Communication SystemDI-718
14.Air Conditioning SystemDI-752
FOR USING OBD II SCAN TOOL OR TOYOTA HAND-HELD TESTER

Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should
be read thoroughly.

If the scan tool or tester cannot communicate with ECU controlled systems when you have connected
the cable of the scan tool or tester to DLC3, turned the ignition switch ON and operated the scan tool,
there is a problem on the vehicle side or tool side.
(1) If communication is normal when the tool is connected to another vehicle, inspect the diagnosis
data link line (Bus
line) or ECU power circuit of the vehicle.
(2) If communication is still not possible when the tool is connected to another vehicle, the problem
is probably in the tool itself, so perform the Self Test procedures outline in the Tester Operator's
Manual.

DIAGNOSTIC TROUBLE CODE CHECK PROCEDURE
Diagnostic Trouble
Code Check (Make a
note of and then clear)Confirmation
of SymptomsDiagnostic Trouble
Code CheckProblem Condition
Diagnostic Trouble
Code DisplayProblem symptoms
existSame diagnostic
trouble code is
displayedProblem is still occurring in the diagnostic
circuit
Normal code is
displayedThe problem is still occurring in a place
other than in the diagnostic circuit
(The diagnostic trouble code displayed
first is either for a past problem or it is a
secondary problem)
No problem
symptoms existThe problem occurred in the diagnostic
circuit in the past
Normal Code DisplayProblem symptoms
existNormal code is
displayedThe problem is still occurring in a place
other than in the diagnostic circuit
No problem
symptoms existNormal code is
displayedThe problem occurred in a place other
than in the diagnostic circuit in the past
IN-22- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
22 Author
: Date
:
2001 AVALON (RM808U)
2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK
The diagnostic system in the AVALON fulfills various functions. The first function is the Diagnostic Trouble
Code Check in which a malfunction in the signal circuits to the ECU is stored in code in the ECU memory
at the time of occurrence, to be output by the technician during troubleshooting. Another function is the Input
Signal Check which checks if the signals from various switches are sent to the ECU correctly.
By using these check functions, the problem areas can be narrowed down quickly and troubleshooting can
be performed effectively. Diagnostic functions are incorporated in the following systems in the AVALON.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Diagnostic Test
Mode (Active Test)
Engine
Automatic Transaxle
Anti-Lock Brake System With Electronic Brake Force Distribution (EBD)
ABS With EBD & BA & TRAC & VSC System
Supplemental Restraint System
Cruise Control System
Engine Immobilizer System
Multiplex Communication System
Air Conditioning System (with Check
Mode)
 (with Check
Mode)











In diagnostic trouble code check, it is very important to determine whether the problem indicated by the diag-
nostic trouble code is still occurring or occurred in the past but returned to normal at present. In addition,
it must be checked in the problem symptom check whether the malfunction indicated by the diagnostic
trouble code is directly related to the problem symptom or not. For this reason, the diagnostic trouble codes
should be checked before and after the symptom confirmation to determine the current conditions, as shown
in the table below. If this is not done, it may, depending on the case, result in unnecessary troubleshooting
for normally operating systems, thus making it more difficult to locate the problem, or in repairs not pertinent
to the problem. Therefore, always follow the procedure in correct order and perform the diagnostic trouble
code check.

IN0CI-02
IN-40
- INTRODUCTIONTERMS
40 Author
: Date
:
2001 AVALON (RM808U)
GLOSSARY OF SAE AND TOYOTA TERMS
This glossary lists all SAE-J1930 terms and abbreviations used in this manual in compliance with SAE rec-
ommendations, as well as their TOYOTA equivalents.
SAE
ABBREVIATIONSSAE TERMSTOYOTA TERMS
( )--ABBREVIATIONS
A/CAir ConditioningAir Conditioner
ACLAir CleanerAir Cleaner, A/CL
AIRSecondary Air InjectionAir Injection (AI)
APAccelerator Pedal-
B+Battery Positive Voltage+B, Battery Voltage
BAROBarometric PressureHAC
CACCharge Air CoolerIntercooler
CARBCarburetorCarburetor
CFIContinuous Fuel Injection-
CKPCrankshaft PositionCrank Angle
CLClosed LoopClosed Loop
CMPCamshaft PositionCam Angle
CPPClutch Pedal Position-
CTOXContinuous Trap Oxidizer-
CTPClosed Throttle PositionLL ON, Idle ON
DFIDirect Fuel Injection (Diesel)Direct Injection (DI)
DIDistributor Ignition-
DLC1
DLC2
DLC3Data Link Connector 1
Data Link Connector 2
Data Link Connector 31: Check Connector
2: Total Diagnosis Comunication Link (TDCL)
3: OBD II Diagnostic Connector
DTCDiagnostic Trouble CodeDiagnostic Code
DTMDiagnostic Test Mode-
ECLEngine Control Level-
ECMEngine Control ModuleEngine ECU (Electronic Control Unit)
ECTEngine Coolant TemperatureCoolant Temperature, Water Temperature (THW)
EEPROMElectrically Erasable Programmable Read Only Memory
Electrically Erasable Programmable Read Only Memory
(EEPROM),
Erasable Programmable Read Only Memory (EPROM)
EFEEarly Fuel EvaporationCold Mixture Heater (CMH), Heat Control Valve (HCV)
EGRExhaust Gas RecirculationExhaust Gas Recirculation (EGR)
EIElectronic IgnitionTOYOTA Distributorless Ignition (TDI)
EMEngine ModificationEngine Modification (EM)
EPROMErasable Programmable Read Only MemoryProgrammable Read Only Memory (PROM)
EVAPEvaporative EmissionEvaporative Emission Control (EVAP)
FCFan Control-
FEEPROMFlash Electrically Erasable Programmable
Read Only Memory-
FEPROMFlash Erasable Programmable Read Only Memory-
FFFlexible Fuel-
FPFuel PumpFuel Pump
GENGeneratorAlternator
GNDGroundGround (GND)

PP0B8-04
- PREPARATIONAIR CONDITIONING
PP-65
11 5 Author
: Date
:
2001 AVALON (RM808U)
EQUIPMENT
Voltmeter
Ammeter
Ohmmeter
Test lead
ThermometerSensor, ECT switch
Torque wrench
Dial indicatorMagnetic clutch
Plastic hammerMagnetic clutch

PP0B9-09
PP-66
- PREPARATIONAIR CONDITIONING
11 6 Author
: Date
:
2001 AVALON (RM808U)
LUBRICANT
ItemCapacityClassification
Compressor oil-ND-OIL 8 or equivalent
When replacing condenser40 cc (1.4 fl.oz.)
When replacing evaporator40 cc (1.4 fl.oz.)
When replacing compressor120 cc (4.1 fl.oz.)

PP0B7-02
PP-64
- PREPARATIONAIR CONDITIONING
11 4 Author
: Date
:
2001 AVALON (RM808U)
RECOMMENDED TOOLS
09082-00040TOYOTA Electrical Tester.
09216-00021Belt Tension Gauge .