Page 2505 of 4323

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.
Page 2506 of 4323

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
Page 2507 of 4323

± 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
Page 2508 of 4323

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
Page 2509 of 4323

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
Page 2510 of 4323

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
Page 2511 of 4323

± 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
Page 2512 of 4323

DIDKQ±01
D05981DLC3
I15897
Trouble Code Display
I15897DEF. SW
DI±2310
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2504 Author: Date:
2005 SEQUOIA (RM1146U)
DTC CHECK / CLEAR
1. DTC CHECK USING HAND±HELD TESTER
(a) Hook up the hand±held tester to the DLC3.
(b) Turn the ignition switch to the ON position.
(c) Read the DTCs following the prompts on the tester
screen.
Refer to the hand±held tester operator's manual for fur-
ther details.
(d) Clear the DTCs.
HINT:
After repairing the malfunctions, clear the DTCs.
(1) Connect the hand±held tester to the DLC3.
(2) Turn the ignition switch to the ON position.
(3) Erase the DTCs following the prompts on the tester
screen.
HINT:
Refer to the hand±held tester operator's manual for further de-
tails.
2. DTC CHECK (SENSOR CHECK)
(a) Perform an indicator check. After the indicator check is
completed, the system enters the DTC check mode auto-
matically (See page DI±2312).
(b) Read the DTC displayed on the panel. Refer to the list of
DTCs on page DI±2317 when reading the DTCs (DTCs
are output on the temperature display.).
If the slower display is desired, press the DEF. SW and
change it to step operation. Each time the Temp. Control
switch is pressed, the display changes by 1 step.