2001 TOYOTA SEQUOIA engine

± 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

± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2309
2503 Author: Date:
2005 SEQUOIA (RM1146U)Symbols (Terminals No.)
Wiring ColorTerminal DescriptionConditionSpecified Condition
TS e S5±TSLGBSl i lIG ON08t 43VTS e S5 TS
(I20±14 e I20±21)LG e BSolar sensor signalIG ON0.8 to 4.3 V
AIR e GNDGWOAir inlet control servomo-IG ON, Push FRS switchBelow 1.0 VAIR e GND
(I20±20 e I19±10)G±W e OAir inlet control servomo
tor operation signalIG ON, Push REC switch10 to 14 V
AIF e GNDROAir inlet control servomo-IG ON, Push FRS switch10 to 14 VAIF e GND
(I20±8 e I19±10)R e OAir inlet control servomo
tor operation signalIG ON, Push REC switchBelow 1.0 V
TPI e SG±TPIWYRAir inlet control servomo-IG ON, Push REC switch3.5 to 4.5 VTPI e SG TPI
(I20±16 e I20±13)W e Y±RAir inlet control servomo
tor control signalIG ON, Push FRS switch0.5 to 1.5 V
RTRSG R TRRttIG ON, Rr room temp.: 25°C (77°F)1.8 to 2.2 VRrTR e SG±RrTR
(I22±13 e I22±14)*1GR±R e R±YRear room temperature
sensor signalIG ON, Rr room temp.: 40°C
(104°F)1.2 to 1.6 V
FACE eGND
(I20±5 e I19±10)GR e OAir outlet control servo-
motor control signalMode control switch: except FACE
" FACE10 to 14 " Below 1.0 V
B/L eGND
(I20±6 e I19±10)BR±W e OAir outlet control servo-
motor control signalMode control switch: except BI±
LEVEL " BI±LEVEL10 to 14 " Below 1.0 V
IGN e GNDYGOEi lti i lE i idliPl tiIGN e GND
(I22±3 e I19±10)Y±G e OEngine revolution signalEngine idlingPulse generation
TW e GNDWROEngine coolant tempera-IG ONPl tiTW e GND
(I22±2 e I19±10)W±R e OEngine coolant tem era
ture sensor signalIG ONPulse generation
ACT eGND
(I22±5 e I19±10)LG±B e OCompressor operation
signalIG ON, A/C switch: OFF " ONBelow 1.0 "10 to 14 V
TE e SG±TEGBWGEvaporator temperature
IG ON, Evaporator temp.: 0°C
(32°F)2.0 to 2.4 VTE e SG TE
(I20±4 e I20±2)G±B e W±GEva orator tem erature
sensor signalIG ON, Evaporator temp.: 15°C
(59°F)1.4 to 1.8 V
MGC eGND
(I19±5 e I19±10)L e OMagnetic clutch control
signalEngine start
A/C switch: OFF " ON10 to 14 " Below 1.0 V
LOCK eGND
(I19±9 e I19±10)W±R e OCompressor lock sensor
signalEngine start
A/C switch: OFF " ONPulse generation
*1: w/ Rear A/C

I22575
DOME Fuse Engine Room J/B
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2311
2505 Author: Date:
2005 SEQUOIA (RM1146U)
3. CLEARING DTC
(a) Pull out the DOME fuse from the engine room J/B for 10
sec. or longer to clear the diagnostic DTC's memory.
(b) After reinserting the fuse, check that the normal code is
output.

DIDKS±01
DI±2314
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2508 Author: Date:
2005 SEQUOIA (RM1146U)
DATA LIST / ACTIVE TEST
1. DATA LIST
HINT:
From the DATA LIST displayed on the hand±held tester, you can read the values of the displays, sensors,
actuators and so on without part removal. Reading the DATA LIST as the first step of troubleshooting is one
way to shorten labor time.
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) From the display on the tester, select ºDATA LISTº.
AIR CONDITIONING:
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic Note
ROOM TEMP
Room temperature sensor /
min.: ±6.5°C (20.3°F)
max.: 57.25°C (135.05°F)Actual room temperature is dis-
played
Open in the circuit:
±6.5°C (20.3°F)
Short in the circuit:
57.25°C (135.05°F)
AMBI TEMP SENS
Ambient temperature sensor /
min.: ±30.8°C (±23.44°F)
max.: 50.8°C (123.44°F)Actual ambient temperature is dis-
played
Open in the circuit:
±30.8°C (±23.44°F)
Short in the circuit:
50.8°C (123.44°F)
EVAP TEMP
Evaporator temperature sensor /
min.: ±29.7°C (±21.46°F)
max.: 59.55°C (139.19°F)Actual evaporator temperature is
displayed
Open in the circuit:
±29.7°C (±21.46°F)
Short in the circuit:
59.55°C (139.19°F)
SOLAR SENS±DSolar sensor (Driver side) /
min.: 0 max.: 255Increases as brightness increasesOpen in the circuit: 0
Short in the circuit: 255
COOLANT TEMP
Engine coolant temperature /
min.: 1.3°C (34.34°F)
max.: 90.55°C (194.99°F)Actual engine coolant temperature
is displayed while the engine is
warmed up
±
SET TEMP±DSet temperature (Driver side) /
min.: 0 max.: 255Set temperature and displayed
temperature are the same±
ESTIMATE TEMP±D
Estimated temperature (Driver
side) / min.: ±200°C (±328°F)
max.: 200°C (392°F)Damper is at ºMAX. COOLº:
±200°C (±328°F)
Damper is at ºMAX. HOTº:
200°C (392°F)
±
A/M DAMP POS±DAir mix damper position (Driver
side) / min.: ±14% max.: 113.5%
Damper is at ºMAX. COOLº:
±10.0%
Damper is at ºMAX. HOTº:
100.0%
±
A/I DAMP POSAir inlet damper position /
min.: ±9% max.: 109%
Damper is at ºRECIRCULATIONº:
±9%
Damper is at ºFRESHº: 109.0%
Damper is at ºHALF±RECIR-
CULATIONº: 30.0 to 80.0%
Open in the circuit: 50.0%
A/M DAMP TARG±D
Air mix damper target position
(Driver side) /
min.: ±14% max.: 113.5%Damper is at ºMAX. COOLº:
±10.0%
Damper is at ºMAX. HOTº:
100.0%
±
A/I DAMP TARGAir inlet damper target position /
min.: ±9% max.: 109%
Damper is at ºRECIRCULATIONº:
±9%
Damper is at ºFRESHº: 109.0%
Damper is at ºHALF±RECIR-
CULATIONº: 30.0 to 80.0%
Open in the circuit: 50.0%

± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2315
2509 Author: Date:
2005 SEQUOIA (RM1146U)BLOWER LEVEL
Blower motor speed level /
min.: Level 0 max.: 31Increases within a range between
0 and 31 as the speed increases.±
AMBI TEMP
Adjusted ambient temperature /
min.: ±30.8°C (±23.44°F)
max.: 50.8°C (123.44°F)
±±
SET TEMP SHIFTShift set temperature / +2C, +1C,
NORMAL, ±1C, ±2CCustomized value will be dis-
played±
AIR INLET MODEAir inlet mode / AUTO, MANUALCustomized value will be dis-
played±
COMPRESSOR MODECompressor mode / AUTO,
MANUALCustomized value will be dis-
played±
COMPRS/DEF OPERCompressor / DEF operation
mode / LINK, NORMALCustomized value will be dis-
played±
FOOT/DEF MODEFoot / DEF auto mode / ON, OFFCustomized value will be dis-
played±
DESTINATION
Destination / DOMEST, USA, EU-
ROPE, AUSTRAL, MIDEAST, NO
INFO
Changes with destination±
REAR ROOM TEMP
Room temperature sensor (Rear) /
min.: ±6.5°C (20.3°F)
max.: 57.25°C (135.05°F)Actual room temperature is dis-
played
Open in the circuit:
±6.5°C (20.3°F)
Short in the circuit:
57.25°C (135.05°F)
R±EVAP TEMP
Evaporator temperature sensor /
min.: ±29.7°C (±21.46°F)
max.: 59.55°C (139.19°F)Actual evaporator temperature is
displayed
Open in the circuit:
±29.7°C (±21.46°F)
Short in the circuit:
59.55°C (139.19°F)
SET TEMP REARSet temperature (Rear side) /
min.: 0 max.: 255Set temperature and displayed
temperature are the same.±
ESTIMATE TEMP±R
Estimated temperature (Rear side)
/ min.: ±200°C (±328°F)
max.: 200°C (392°F)Damper is at ºMAX. COOLº:
±200°C (±328°F)
Damper is at ºMAX. HOTº:
200°C (392°F)
±
A/M DAMP POS±RAir mix damper position (Rear
side) / min.: ±14% max.: 113.5%
Damper is at ºMAX. COOLº:
±10.0%
Damper is at ºMAX. HOTº
100.0%
±
A/M DAMP TARG±R
Air mix damper target position
(Rear side) /
min.: ±14% max.: 113.5%Damper is at ºMAX. COOLº:
±10.0%
Damper is at ºMAX. HOTº
100.0%
±
BLOWER LEVEL±RBlower motor speed level /
min.: Level 0 max.: 31Increases within a range between
0 and 31 as the speed increases.±
#CODESNumber of trouble codes /
min.: 0 max.: 255Number of DTCs will be displayed±
ENGINE AND ECT / ALL:
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic Note
A/C SIGA/C signal / ON or OFFA/C ON: ON±
A/C MAG CLUTCHA/C magnet clutch / ON or OFFA/C magnet clutch ON: ON±

DI3F1±09
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2317
2511 Author: Date:
2005 SEQUOIA (RM1146U)
DIAGNOSTIC TROUBLE CODE CHART
If a malfunction code is displayed during the DTC check, check the circuit listed for that code in the table
below (Proceed to the page given for that circuit.)
DTC No.
(See page)Detection ItemTrouble AreaMemory
00Normal±±
11 *1
(DI±2319)
Front room temperature sensor circuit
Front room temp. sensor

Harness or connector between front room temp. sensor and
integration control and panel

Integration control and panel

(8.5 min. or more)
12 *2
(DI±2322)
Ambient temperature sensor circuit
Ambient temp. sensor

Harness or connector between ambient temp. sensor and
integration control and panel

Integration control and panel

(8.5 min. or more)
13
(DI±2325)
Front evaporator temperature sensor
circuit
Front evaporator temp. sensor

Harness or connector between front evaporator temp. sen-
sor and integration control and panel

Integration control and panel

(8.5 min. or more)
14
(DI±2328)
Engine coolant temperature sensor cir-
cuit
Engine coolant temp. sensor

Harness or connector between engine coolant temp. sensor
and ECM

Harness or connector between ECM and integration control
and panel

Integration control and panel

ECM
±
17
(DI±2330)
Rear evaporator temperature sensor
circuit
Rear evaporator temp. sensor

Harness or connector between rear evaporator temp. sensor
and integration control and panel

Integration control and panel

(8.5 min. or more)
19 *1
(DI±2333)
Rear room temperature sensor circuit
Rear room temp. sensor

Harness or connector between rear room temp. sensor and
integration control and panel

Integration control and panel

(8.5 min. or more)
21 *3
Solar sensor circuit (Open)
Solar sensor

Harness or connector between solar sensor and integration±
21 *3
(DI±2336)Solar sensor circuit (Short)
Harness or connector between solar sensor and integration
control and panel

Integration control and panel

(8.5 min. or more)
22 *4
(DI±2339)
All conditions below are detected for 3
sec. or more
(a) Engine speed: 450 rpm or more
(b) Ratio between engine and compres-
sor rpm deviates 20% or more in com-
parison to normal operation.
Compressor drive belt

Compressor lock sensor

Compressor

Harness or connector between compressor lock sensor and
integration control and panel

Integration control and panel
±
23
(DI±2342)
Open in pressure sensor circuit
Abnormal refrigerant pressure
[below 196 kPa (2.0 kgf/cm
2, 28 psi)
over 3,140 kPa (32.0 kgf/cm2, 455 psi)]

Pressure switch

Harness or connector between pressure switch and integra-
tion control and panel

Refrigerant pipe line

Integration control and panel
±

DI±2318
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2512 Author: Date:
2005 SEQUOIA (RM1146U)31
(DI±2346)
Front air mix damper position sensor
circuit
Front air mix damper position sensor

Harness or connector between front air mix damper position
sensor and integration control and panel

Integration control and panel

(1 min. or more)
32
(DI±2349)
Air inlet damper position sensor circuit
Air inlet damper position sensor

Harness or connector between air inlet damper position
sensor and integration control and panel

Integration control and panel

(1 min. or more)
37
(DI±2352)
Water valve damper position sensor cir-
cuit
Water valve damper position sensor

Harness or connector between water valve damper position
sensor and integration control and panel

Integration control and panel

(1 min. or more)
41
(DI±2355)
Front air mix damper control servomotor
circuit
Front air mix damper control servomotor

Front air mix damper position sensor

Harness or connector between integration control and panel
and front air mix damper control servomotor

Harness or connector between air mix position sensor and
integration control and panel front

Integration control and panel

(15 sec. or more)
42
(DI±2358)
Air inlet damper control servomotor cir-
cuit
Air inlet damper control servomotor

Air inlet damper position sensor

Harness or connector between air inlet damper control ser-
vomotor and integration control and panel

Harness or connector between air inlet damper position
sensor and integration control and panel

Integration control and panel

(15 sec. or more)
47
(DI±2361)
Water valve damper control servomotor
circuit
Water valve damper control servomotor

Water valve damper position sensor

Harness or connector between water valve damper control
servomotor and integration control and panel

Harness or connector between water valve damper position
sensor and integration control and panel

Integration control and panel

(15 sec. or more)
HINT:

*1 If the room temp. is approx. ±20°C (±4°F) or lower, this DTC may be output even though the system
is normal.

*2
If the ambient temp. is approx. ±50°C (±58°F) or lower, DTC 12 may be output even though the sys-
tem is normal.

*3
If the check is being performed in a dark place, DTC 21 (solar sensor circuit abnormal) could be dis-
played. In this case, perform DTC check again while illuminating the solar sensor with an inspection
light etc.. If DTC 21 is still displayed, there could be trouble in the solar sensor circuit.

*4
Compressor lock (DTC 22) is indicated only for a current malfunction. (See page DI±2339)
To confirm DTC 22, preform the following steps.
(1) With the engine ON, enter the DTC check mode.
(2) Press the R/F switch to enter actuator check mode, and set the operation to Step No. 3.
(3) Press the AUTO switch to return to DTC check mode.
(4) The DTC is displayed after approx. 3 sec.

I08286
E2
Engine Coolant
Temp. Sensor
1 2Integration Control and Panel
I22 E821
28
E8E2 THWECM
THWO
E5 14
W±R2 G±Y
G±WTW DI±2328
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2522 Author: Date:
2005 SEQUOIA (RM1146U)
DTC 14 Engine Coolant Temperature Sensor Circuit
CIRCUIT DESCRIPTION
This sensor detects the engine coolant temperature and sends the appropriate signals to the integration
control and panel. These signals are used for warm up control when the engine is cold.
DTC No.Detection ItemTrouble Area
14Open or short in engine coolant temperature sensor circuit.

Engine coolant temp. sensor

Harness or connector between engine coolant temp. sensor
and ECM

Harness or connector between ECM and integration control
and panel

ECM

Integration control and panel
WIRING DIAGRAM
DI935±03