2001 TOYOTA SEQUOIA heater

DI±2000
± DIAGNOSTICSAUDIO SYSTEM
2194 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
NOTICE:
The vehicle is equipped with SRS (Supplemental Restraint System) such as airbags. Before servic-
ing (including removal or installation of parts), be sure to read the precautionary notice for the sup-
plemental restraint system (See page RS±1).
1 Check illumination.
CHECK:
Check if the illumination for the radio receiver assy, steering pad switch assy or others (A/C switch, cigarette
lighter, etc.) comes on when the light control switch is turned to the HEAD or TAIL position.
RESULT:
Components with illuminationGo to step
Illumination comes on for all components except radio receiver assy.A
Illumination comes on for all components except steering pad switch does not
come on.B
Illumination comes on for all components except radio receiver assy, steering
pad switch, Rear heater control panel, each switch, etc.C
All illumination does not come on. (Radio receiver assy, steering pad switch,
Combination meter, Rear heater control panel, each switch, etc.)D
HINT:
If the illuminations have malfunctions, check the rheostat switch.
B Go to step 4.
C Go to step 8.
D Go to combination meter system
(See page DI±1645).
A

± DIAGNOSTICSAUDIO SYSTEM
DI±2027
2221 Author: Date:
2005 SEQUOIA (RM1146U)
Noise occurs
INSPECTION PROCEDURE
1 Check of speaker installation.
CHECK:
Check if each speaker is securely installed.
OK:
Each speaker is securely installed.
HINT:
The radio is equipped with a noise prevention system that blocks excessively loud noise. If such noise oc-
curs, check the all wiring is proper and that the antenna installation part ground and noise±prevention equip-
ment are installed.
Condition in which noise occursNoise type
Noise increases when the accelerator pedal is depressed, but stops when
the engine is stopped.Generator noise
Noise occurs during A/C or the heater operation.Blower motor noise
Noise occurs when the vehicle accelerates rapidly on an unpaved road or
after the ignition switch is turned on.Fuel pump noise
Noise occurs when the horn switch is pressed and released or when pressed
and held.Horn noise
Quiet noise occurs while the engine is running, but stops when the engine is
stopped.Ignition noise
Noise occurs synchronously with the blink of the turn signal.Flasher noise
Noise occurs during window washer operation.Washer noise
Noise occurs while the engine is running, and it continues even after the en-
gine is stopped.Water temperature sensor noise
Noise occurs during wiper operation.Wiper noise
Noise occurs when the brake pedal is depressed.Stop light switch noise
Others.Static electricity stored on the vehicle
HINT:

Identify the condition under which the noise occurs, and check the noise filter on the related part.

First ensure that the noise is not coming from the outside. Failure to do so makes noise source detec-
tion difficult and may lead to a misdiagnosis.

Noise should be removed in descending order of loudness.
NG Install it properly.
OK
Identification of noise source (See page DI±1964).
DIDA3±01

± DIAGNOSTICSNAVIGATION SYSTEM
DI±2233
2427 Author: Date:
2005 SEQUOIA (RM1146U)
Abnormal noise occurs
INSPECTION PROCEDURE
1 Check speaker installation
CHECK:
Check if each speaker is securely installed.
OK:
Each speaker is securely installed.
HINT:
The radio is equipped with a noise prevention system that blocks only excessively loud noise. If loud noise
occurs, check that all wiring is proper and that the antenna installation part ground and noise±prevention
equipment are installed.
Conditions under which noise occursNoise type
Noise increases when the accelerator pedal is depressed, but stops when
the engine is stopped.Generator noise
Noise occurs during A/C or heater operation.Blower motor noise
Noise occurs when the vehicle accelerates rapidly on an unpaved road or
after the ignition switch is turned on.Fuel pump noise
Noise occurs when the horn switch is pressed and released or when pressed
and held.Horn noise
Quiet noise is occurs while the engine is running, but stops when the engine
is stopped.Ignition noise
Noise occurs synchronously with the blink of the turn signal.Flasher noise
Noise occurs during window washer operation.Washer noise
Noise occurs while the engine is running, and continues even after the engine
is stopped.Water temperature sensor noise
Noise occurs during wiper operation.Wiper noise
Noise occurs when the brake pedal is depressed.Stop light switch noise
Others.Static electricity stored on the vehicle
HINT:

Identify the condition under which the noise occurs, and check the noise filter on the relevant part.

First ensure that the noise is not coming from outside. Failure to do so makes noise source detection
difficult and may lead to a misdiagnosis.

Noise should be removed in descending order of loudness.
NG Install it properly.
OK
Identification of noise source (See page DI±2174).
DIDCO±01

± DIAGNOSTICSNAVIGATION SYSTEM
DI±2261
2455 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
NOTICE:
The vehicle is equipped with SRS (Supplemental Restraint System) such as airbags. Before servic-
ing (including removal or installation of parts), be sure to read the precautionary notice for the sup-
plemental restraint system (See page RS±1).
1 Check illumination.
CHECK:
Check if the illumination for the radio and navigation assy, steering pad switch assy or others (A/C switch,
cigarette lighter, etc.) comes on when the light control switch is turned to the HEAD or TAIL position.
RESULT:
Components with illuminationGo to step
Illumination comes on for all components except radio and navigation assy.A
Illumination comes on for all components except steering pad switch.B
Illumination comes on for all components except radio and navigation assy,
steering pad switch, Rear heater control panel, each switch, etc.C
All illumination does not come on. (Radio and navigation assy, steering pad
switch, Combination meter, Rear heater control panel, each switch, etc.)D
HINT:
If the illuminations have malfunctions, check the rheostat switch.
B Go to step 4.
C Go to step 8.
D Go to combination meter system
(See page DI±1645).
A

DIDKN±01
I28851
R/B No. 2

Heater Main Relay
(Marking: HTR)
Compressor
Condenser
Receiver Pressure Switch
Integration Panel Assembly

A/C ECU

A/C Switch

Air Inlet Selector
Heater Unit

Heater Radiator

Air Mix Servomotor

Air Outlet Servomotor
Cooling Unit

Blower Motor Linear
Controller

Evaporator

Expansion Valve

ThermistorBlower Unit

Blower Motor

Air Inlet Servomotor
Water Valve
Rear Heater
Control Assembly
Condenser Fan
Ambient
Temperature
Sensor
Solar Sensor
Room
Temperature
Sensor
Rear Room Temperature
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2299
2493 Author: Date:
2005 SEQUOIA (RM1146U)
LOCATION

I21419
Water Valve
Air Outlet
Servomotor
Heater Radiator
Thermistor
Evaporator
Expansion Valve Power Transistor Blower Motor
DI±2300
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2494 Author: Date:
2005 SEQUOIA (RM1146U)

DI3F3±10
DI±2304
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2498 Author: Date:
2005 SEQUOIA (RM1146U)
PROBLEM SYMPTOMS TABLE
Front A/C:
SymptomSuspected AreaSee page
Whole functions of the A/C system do not operate4. Integration control and panel
5. IG power source circuitIN±35
DI±2363
Air Flow Control: No blower operation
1. IG power source circuit
2. Heater main relay
3. Blower motor circuit
4. Integration control and panel
5. Blower motor controllerDI±2363
AC±95
DI±2374
IN±35
AC±83
Air Flow Control: No blower control
1. Blower motor circuit
2. Integration control and panel
3. Solar sensor circuit
4. Blower motor controllerDI±2374
IN±35
DI±2336
AC±83
Air Flow Control: Insufficient air flow1. Blower motor circuitDI±2374
Temperature Control: No cool air comes out
1. Refrigerant volume
2. Drive belt tension
3. Refrigeration system inspection with manifold gauge set
4. Compressor circuit
5. Pressure switch circuit
6. Front air mix damper position sensor circuit
7. Front air mix damper control servomotor circuit
8. Front room temp. sensor circuit
9. Ambient temp. sensor circuit
10.Vehicle speed signal circuit
11. Integration control and panelAC±23
AC±15
AC±3
DI±2381
DI±2342
DI±2346
DI±2355
DI±2319
DI±2322
DI±2370
IN±35
Temperature Control: No warm air comes out
1. Front air mix damper position sensor circuit
2. Front air mix damper control servomotor circuit
3. Front room temp. sensor circuit
4. Ambient temp. sensor circuit
5. Vehicle speed signal circuit
6. Front evaporator temp. sensor circuit
7. Integration control and panelDI±2346
DI±2355
DI±2319
DI±2322
DI±2370
DI±2325
IN±35
Temperature Control: Output air is warmer or cooler than the set
temperature or response is slow
1. Refrigerant volume
2. Drive belt tension
3. Refrigeration system inspection with manifold gauge set
4. Cooling fan system
5. Solar sensor circuit
6. Front room temp. sensor circuit
7. Ambient temp. sensor circuit
8. Vehicle speed signal circuit
9. Front evaporator temp. sensor circuit
10.Front air mix damper position sensor circuit
11. Front air mix damper control servomotor circuit
12.Front air inlet damper position sensor circuit
13.Front air inlet damper control servomotor circuit
14.Condenser
15.Evaporator
16.Heater radiator
17.Expansion valve
18.Integration control and panelAC±23
AC±15
AC±3
AC±96
DI±2336
DI±2319
DI±2322
DI±2370
DI±2325
DI±2346
DI±2355
DI±2349
DI±2358
AC±65
AC±24
AC±35
AC±29
IN±35

± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2305
2499 Author: Date:
2005 SEQUOIA (RM1146U)Symptom
Suspected AreaSee page
Temperature Control: No temperature control (only Max. cool or
Max. warm)
1. Front room temp. sensor circuit
2. Ambient temp. sensor circuit
3. Front air mix damper position sensor circuit
4. Front air mix damper control servomotor circuit
5. Integration control and panelDI±2319
DI±2322
DI±2346
DI±2355
IN±35
No air inlet control
1. Front air inlet damper position sensor circuit
2. Front air inlet damper control servomotor circuit
3. Integration control and panelDI±2349
DI±2358
IN±35
No air flow control
1. Air outlet damper position sensor circuit
2. Air outlet damper control servomotor circuit
3. Integration control and panelAC±35
AC±35
IN±35
Engine idle up does not occur, or is continuous1. Compressor circuit
2. ECMDI±2381
DI±34
No DTC is recorded. Set mode is cleared when IG switch is
turned off.1. Back±up power source circuit
2. Integration control and panelDI±2366
IN±35
Rear A/C:
SymptomSuspected AreaSee page
Whole functions of the rear A/C system do not operate
1. Heater control assembly
2. Integration control and panel
3. ACC power source circuitIN±35
DI±2368
DI±2368
Air Flow Control: No blower operation
1. ACC power source circuit
2. Rear heater main relay
3. Rear blower motor
4. Rear blower motor controller
5. Heater control assembly
6. Integration control and panelDI±2368
AC±95
AC±45
±
IN±35
DI±2368
Air Flow Control: No blower control
1. Rear heater main relay
2. Rear blower motor
3. Rear blower motor controller
4. Heater control assembly
5. Integration control and panel
6. Solar sensor circuitAC±95
AC±45
±
IN±35
DI±2336
DI±2368
Air Flow Control: Insufficient air flow1. Rear blower motor
2. Rear blower resisterAC±45
±
Temperature Control: No cool air comes out
1. Refrigerant volume
2. Drive belt tension
3. Refrigeration system inspection with manifold gauge set
4. Compressor circuit
5. Pressure switch circuit
6. Water valve damper position sensor circuit
7. Water valve damper control servomotor circuit
8. Rear room temp. sensor circuit
9. Ambient temp. sensor circuit
10.ECM
11. Heater control assembly
12.Integration control and panelAC±23
AC±15
AC±3
DI±2381
DI±2342
DI±2352
DI±2361
DI±2333
DI±2322
DI±34
DI±2368
IN±35
Temperature Control: No warm air comes out
1. Water valve damper position sensor circuit
2. Water valve damper control servomotor circuit
3. Rear room temp. sensor circuit
4. Ambient temp. sensor circuit
5. Rear evaporator temp. sensor circuit
6. Heater control assembly
7. Integration control and panelDI±2352
DI±2361
DI±2333
DI±2322
DI±2330
IN±35
IN±35