TOYOTA SEQUOIA 2001 Service Repair Manual

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)

DI3EY±08
Customer Problem Analysis
Check and Clear DTC (Pre±check)
Vehicle Brought to Workshop
Problem Symptom ConfirmationSymptom Simulation Symptom does not
occur
DTC Check
Normal code
DTC ChartProblem Symptoms Table
Circuit InspectionActuator Check
Parts Inspection
Identification of Problem
Repair
Confirmation TestEndItems inside
are titles of pages in this
manual with the page number indicated in the
bottom portion. See the indicated pages
for detailed explanations.
1
2
34
5
67
89
10P. DI±2310
P. IN±24
P. DI±2317
P. DI±2304
P. DI±2319 to DI±2381 P. DI±2310
Malfunction codeP. DI±2302
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2301
2495 Author: Date:
2005 SEQUOIA (RM1146U)
HOW TO PROCEED WITH TROUBLESHOOTING
Perform troubleshooting in accordance with the procedure on the following page.

DI3EZ±06
Inspector 's name:
Customer 's Name
VIN
Production Date
Licence Plate No.
Odometer Readingkm
miles Date vehicle
Brought In / /
Date of Problem Occurrence
How Often does Problem Occur?
Weather
Outdoor Temperature / /

Continuous
Intermittent ( times a day)

Fine
Cloudy
Snowy
Various /Other

Hot
Warm
Cool
Cold (Approx.°F
°C)
Symptoms
Blower motor does not operate

Blower motor speed does not change
(Always Hi, Always Med, Always Lo)
Air Flow Control is
Faulty

Cabin temperature does not go down

Response is slow

Cannot change between FRS and REC
(Always Fresh or always Recirculating)

Will not enter the desired mode Temperature
Control is Faulty
Air Inlet Control is
Faulty
Vent Control is
Faulty
DTC Check1st Time
2nd Time
Normal Code
Malfunction Code (Code )

Normal Code
Malfunction Code (Code )
AIR CONDITIONING SYSTEM Check Sheet

Cabin temperature does not rise

Mode will not change DI±2302
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2496 Author: Date:
2005 SEQUOIA (RM1146U)
CUSTOMER PROBLEM ANALYSIS CHECK

DIDKO±01
I15897R/F SW
I15897DEF. SW
STEP
1
2
3
4
5
6
7
8
9
10DISPLAY
CODE
Fr
BLOWER
LEVELFr
OUTLETINLET
COMPRESSORFr A/M
DAMPERRr
BLOWER
LEVELRr
OUTLETRr A/M
DAMPER
1
2
3
4
5
6
7
8
9 0
1 0
16
31FACE
B/L
FOOT
F/D
DEFFRS
R/F (50%)
RECOFF
ON±14%
50.0%
113.5%1 0
10
31FACE1
FACE2
B/L1
B/L2
FOOT0.0%
40.0%
60.0%
86.5%
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2303
2497 Author: Date:
2005 SEQUOIA (RM1146U)
ACTUATOR CHECK
1. ACTUATOR CHECK
(a) After entering the sensor check mode, press the R/F
switch (See page DI±2312).
(b) Since each damper, motor and relay automatically oper-
ates at 1 second intervals beginning in order from 20 in
the temperature display, check the temperature and air
flow visually and by hand.
If a slower display is desired, press the DEF. (Fr.) switch
and change it to step operation. Each time the DEF. (Fr.)
switch is pressed, the display changes by 1 step.
HINT:

Codes are displayed in order from the smallest to the larg-
est numbers.

To cancel the check mode, press the OFF switch.

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

DI±2306
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2500 Author: Date:
2005 SEQUOIA (RM1146U) 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. Rear room temp. sensor circuit
7. Ambient temp. sensor circuit
8. Rear evaporator temp. sensor circuit
9. Water valve damper position sensor circuit
10.Water valve damper control servomotor circuit
11. Condenser
12.Evaporator
13.Heater radiator
14.Expansion valve
15.Heater control assembly
16.Integration control and panelAC±23
AC±15
AC±3
AC±96
DI±2336
DI±2333
DI±2322
DI±2330
DI±2352
DI±2361
AC±65
AC±70
AC±45
AC±76
IN±35
IN±35
Temperature Control: No temperature control (only Max. cool or
Max. warm)
1. Rear room temp. sensor circuit
2. Ambient temp. sensor circuit
3. Water valve damper position sensor circuit
4. Water valve damper control servomotor circuit
5. Heater control assembly
6. Integration control and panelDI±2333
DI±2322
DI±2352
DI±2361
IN±35
IN±35

DIDKP±01
I15876
I21 I20I19
I22
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2307
2501 Author: Date:
2005 SEQUOIA (RM1146U)
TERMINALS OF ECU
Integration Control and Panel
Symbols (Terminals No.)Wiring ColorTerminal DescriptionConditionSpecified Condition
+B eGND
(I19±1 e I19±10)R e OPower source (Back±up)Always10 to 14 V
IG+ e GND
(I19±2 e I19±10)R±L e OPower source (IG)IG switch OFF " ON10 to 14 V
PSW e GNDLBOPithil
A/C refrigerant pressure: less than
0.19 MPa
(2.0 kgf/cm2)10 t 14B l 10VPSW e GND
(I19±6 e I19±10)L±B e OPressure switch signal0.19 MPa (2.0 kgf/cm)
or more than 3.14 MPa (32
Kgf/cm2)
10 to 14 " Below 1.0 V
HR e GND
(I22±6 e I19±10)L±Y e OBlower motor operation
signalBlower fan OFF "ON10 to 14 " Below 1.0 V
GND e Body ground
(I19±10 e Body ground)*1O e Body groundGround for main power
supplyConstantContinuity
ACC e GND
(I19±11 e I19±10)P e OPower source (ACC)Turn ignition switch ACC10 to 14 V
TA MSG TAMAbi tt tIG ON, Ambient temp.: 25°C (77°F)1.3 to 1.8 VTAM e SG±TAM
(I19±8 e I19±20)LG±B e Y±BAmbient temperature sen-
sor signalIG ON, Ambient temp.: 40°C
(104°F)0.8 to 1.3 V
BLW e GNDGBOBlower motor operationBl f OFFON10 t 14B l 10VBLW e GND
(I19±4 e I19±10)G±B e OBlower motor o eration
signalBlower fan OFF " ON10 to 14 " Below 1.0 V
RrCLK (I21±15)*1BCommunication signal
Communication circuit
(Built in Fr A/C control panel " Rr
A/C control panel)
±
RrDPD (I21±5)*1RCommunication signal
Communication circuit
(Built in Fr A/C control panel " Rr
A/C control panel)
±
RrSWD (I21±6)*1WCommunication signal
Communication circuit
(Built in Fr A/C control panel " Rr
A/C control panel)
±
RrAMH e GND
(I21±8 e I19±10)*1R±G e ORear air mix control ser-
vomotor operation signalRr temp. control switch: Max.
COOL " Max. HOTBelow 1.0 "
10 to 14 V for 16 sec.
RrAMC e GND
(I21±9 e I19±10)*1L±B e ORear air mix control ser-
vomotor operation signalRr temp. control switch: Max. HOT
" Max. COOLBelow 1.0 "
10 to 14 V for 16 sec.
RrSG e GND
(I21±10 e I19±10)*1L±R e OGround for rear evapora-
tor temperature sensorConstantContinuity
RrS5 e RrSG
(I22±4 e I21±10)*1L±Y e L±RPower supply for rear air
mix control servomotorIG ON4.5 to 5.5 V

DI±2308
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2502 Author: Date:
2005 SEQUOIA (RM1146U)Symbols (Terminals No.)
Wiring ColorTerminal DescriptionConditionSpecified Condition
RrTP e RrSG
(I21±18 e I21±10)*1W e L±RRear air mix damper posi-
tion sensor signalRr temp. control switch: Max.
COOL " Max. HOT4.0 to 1.0 V
AC1 e GND
(I22±4 e I19±10)G ± B e OCompressor operation
signalIG ON, A/C switch: OFF " ON3.7 to 4.5 "
1.3 to 2.6 V
RrFACE2 e GND
(I21±11 e I19±10)*1P±B e ORear air outlet control ser-
vomotor operation signalRr A/C control panel switch: except
FACE " FACE10 to 14 "
Below 1.0 V
RrBLK (I21±4)*1LG±BCommunication signal
Communication circuit
(Built in Fr. A/C control panel " Rr.
A/C control panel)
±
RrSTX (I21±14)*1G±YCommunication signal
Communication circuit
(Built in Fr. A/C control panel " Rr.
A/C control panel)
±
RrVM e GND
(I21±7 e I19±10)*1W±G e ORear blower motor control
signalRr blower control switch: LO " MID
" HI7.2 " 4.2 " 0.5 V
RrHR e GND
(I22±7 e I19±10)*1L±O e ORear blower motor opera-
tion signalRr blower control switch: OFF "
LO10 to 14
"Below 1.0 V
RrBLW e GND
(I21±16 e I19±10)*1L e ORear blower motor opera-
tion signalRr blower control switch: OFF "
LOBelow 1.0 "
1.5 to 3.0 V
RrFACE e GND
(I21±2 e I19±10)*1Y±B e ORear air outlet control ser-
vomotor control signalRr A/C control panel FACE switch:
OFF " ON10 to 14 "
Below 1.0 V while
switch is pushed
RrB/L e GND
(I21±3 e I19±10)*1BR±W e ORear air outlet control ser-
vomotor control signalRr A/C control panel B/L switch:
OFF " ON10 to 14 "
Below 1.0 V while
switch is pushed
RrFOOT e GND
(I21±13 e I19±10)*1G±R e ORear air outlet control ser-
vomotor control signalRr A/C control panel FOOT switch:
OFF " ON10 to 14 "
Below 1.0 V while
switch is pushed
RrTE e RrSG LG RLRRear evaporator tempera-Rr evaporator temp.: 0°C (32°F)2.0 to 2.4 VRrTE e RrSG
(I21±17 e I21±10)*1LG±R e L±RRear eva orator tem era
ture sensor signalRr evaporator temp.: 15°C (59°F)2.0 to 2.4 V
RrB/L2 e GND
(I21±12 e I19±10)*1P±G e ORear air outlet control ser-
vomotor control signalRr A/C control panel switch: except
B/L " B/L10 to 14 "
Below 1.0 V
FOOT eGND
(I21±17 e I19±10)Y±B e OAir outlet control servo-
motor control signalMode control switch except: FOOT
" FOOT10 to 14 " Below 1.0 V
FDEF e GND
(I20±7 e I19±10)LG±R e OAir outlet control servo-
motor control signalMode control switch except: FOOT/
DEF "FOOT/DEF10 to 14 " Below 1.0 V
DEF e GND
(I20±18 e I19±10)B±W e OAir outlet control servo-
motor control signalMode control switch except: DEF "
DEF10 to 14 " Below 1.0 V
AMH e GNDRLOAir mix control servomotorIG ON, Set temp.: Max. CoolBelow 1.0 VAMH e GND
(I20±10 e I19±10)R±L e OAir mix control servomotor
operation signalIG ON, Set temp.: Max. Hot10 to 14 V
S5±AM eSG±TP
(I20±22 e I20±12)R±Y e L±RPower supply for air mix
control servomotorIG ON4.5 to 5.5 V
TP e SG±TPGRLRAir mix damper positionIG ON, Set temp.: Max. Cool3.5 to 4.5 VTP e SG TP
(I20±15 e I20±12)G±R e L±RAir mix dam er osition
sensor signalIG ON, Set temp.: Max. Hot0.5 to 1.5 V
AMC e GNDWLOAir mix control servomotorIG ON, Set temp.: Max. Cool10 to 14 VAMC e GND
(I20±9 e I19±10)W±L e OAir mix control servomotor
control signalIG ON, Set temp.: Max. HotBelow 1.0 V
S5±AI e SG±TPI
(I20±11 e I20±13)L±B e Y±RAir inlet control servomo-
tor control signalIG ON4.5 to 5.5 V
TR e SG±TRLWRWRoom temperature sensorIG ON, Cabin temp.: 25°C (77°F)1.8 to 2.2 VTR e SG TR
(I20±3 e I20±1)L±W e R±WRoom tem erature sensor
signalIG ON, Cabin temp.: 40°C (104°F)1.2 to 1.6 V