Page 2545 of 4323
I28836
Integration Control
and Panel
PSW L±B
R±YR±Y
4A4
A/C Pressure Switch
I19
C46
IA5
1
J3
J/C
From
HTR FuseL±B
CDual
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2343
2537 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
Page 2546 of 4323

I29010
Pressure switch:
A4
DI±2344
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2538 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check refrigerant pressure.
(a) Set the manifold gauge.
(b) Read the manifold gauge pressure when these conditions are established.
Test conditions:
Temperature at the air inlet with the switch set at RECIRC is 30 to 35°C (86 to 95°F)
Engine running at 1,500 rpm
Blower speed control switch at ºHIº position
Temperature control dial at ºCOOLº position
Air conditioning switch ON
Fully open doors
Standard:
Pressure on high pressure side:
1.37 to 1.57 MPa (13.9 to 16.0 kgfVcm
2, 198 to 228 psi)
HINT:
If the refrigerant pressure is below 196 KPa (2.0 kgfVcm
2, 28 psi), the refrigerant amount the air conditioning
cycle may have decreased significantly for reasons such as a gas leakage.
NG Check air conditioning cycle
(See page AC±3).
OK
2 Check air conditioning operation.
(a) Disconnect the pressure switch connector.
(b) Connect terminals 1 and 4 of the connector of the pres-
sure switch on the vehicle wire harness side using a ser-
vice wire.
(c) Start the engine.
(d) Turn the air conditioning switch is on and check that the
magnet clutch is turned on.
(e) Check that the magnet clutch is turned off when discon-
necting terminals 1 and 4 (that are connected in the prior
step).
OK:
Terminals 1 and 4 connected: magnet clutch is on
Terminals 1 and 4 disconnected: magnet clutch is off
NG Go to step 3.
OK
Page 2547 of 4323
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2345
2539 Author: Date:
2005 SEQUOIA (RM1146U)
Replace pressure switch.
3 Check harness and connector between pressure switch and integration control
and panel (See page IN±35).
Result:
NGA
OK (Checking from the PROBLEM SYMPTOMS TABLE)B
OK (Checking from the DTC)C
A Repair or replace harness or connector.
B Proceed to next circuit inspection shown in
problem symptoms table (See page DI±2304).
OK
Replace integration control and panel.
Page 2548 of 4323

4 (V)
1
TP terminal voltage0 100 %
(Cool)
(Hot)
Damper opening angle
I28837
A17
Air Mix Control
Servomotor (Front)
5
L±R 4 322
15
12S5±AM
TP
SG±TP Integration Control
and Panel
I20 R±Y
G±R VZ
PT
GNDI20
I20 DI±2346
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2540 Author: Date:
2005 SEQUOIA (RM1146U)
DTC 31 Front Air Mix Damper Position Sensor Cir-
cuit
CIRCUIT DESCRIPTION
This sensor detects the position of the air mix damper and
sends the appropriate signals to the integration control and
panel.
The position sensor is built into the air mix damper control ser-
vomotor assembly.
DTC No.Detection ItemTrouble Area
31Short to ground or short to power source circuit in front air mix
Front air mix damper position sensor
Harness or connector between front air mix damper position
31Short to ground or short to ower source circuit in front air mix
damper position sensor circuit.
Harness or connector between front air mix dam er osition
sensor and integration control and panel
Integration control and panel
WIRING DIAGRAM
DI3FF±10
Page 2549 of 4323
I28847
SG±TP TPI20 Integration Control and Panel:
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2347
2541 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check voltage between terminals TP and SG±TP of integration control and pan-
el.
PREPARATION:
Remove the integration control and panel with connectors still
connected.
CHECK:
(a) Turn the ignition switch to ON.
(b) Change the set temperature to activate the front air mix
damper control servomotor, and measure the voltage be-
tween terminals TP and SG±TP of the integration control
and panel connector each time the set temperature is
changed.
OK:
Set TemperatureVoltage
Max. cool3.5 to 4.5 V
Max. hot0.5 to 1.5 V
HINT:
As the set temperature increases, the voltage decreases.
NG Go to step 2.
Ok
Proceed to next circuit inspection shown in problem symptoms table (See page DI±2304). How-
ever, if DTC 31 is displayed, replace integration control and panel.
Page 2550 of 4323
I15902
Cool
Warm
DI±2348
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2542 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check front air mix damper position sensor.
PREPARATION:
Remove the front air mix servomotor (See page AC±86).
CHECK:
Measure the resistance between terminals 3 and 4 of the front
air mix servomotor connector.
OK:
Resistance : 4.2 to 7.8 kW
CHECK:
While operating the front air mix servomotor, following the pro-
cedure on page DI±2355, measure the resistance between ter-
minals 3 and 4 of the front air mix servomotor connector.
OK:
PositionResistance
Max. cool3.6 to 6.8 kW
Max. warm0.5 to 1.1 kW
HINT:
As the front air mix servomotor moves from the cool side to the
warm side, the resistance decreases.
NG Replace front air mix servomotor.
OK
3 Check harness and connector between front air mix damper position sensor and
integration control and panel (See page IN±35).
NG Repair or replace harness or connector.
OK
Replace integration control and panel.
Page 2551 of 4323

(V)
4
1
0
100 %
TPI terminal voltage
Damper opening angle
I15866
A16
Air Inlet Control
Servomotor
1
Y±R 2 311
16
13S5±AI
TPI
SG±TPI Integration Control
and Panel
I20 L±B
W VZ
PT
GNDI20
I20
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2349
2543 Author: Date:
2005 SEQUOIA (RM1146U)
DTC 32 Air Inlet Damper Position Sensor Circuit
CIRCUIT DESCRIPTION
This sensor detects the position of the air inlet damper and
sends the appropriate signals to the integration control and
panel.
The position sensor is built into the air inlet damper control ser-
vomotor assembly.
DTC No.Detection ItemTrouble Area
32Short to ground or short to power source circuit in air inlet
Air inlet damper position sensor
Harness or connector between air inlet damper position sen-
32Short to ground or short to ower source circuit in air inlet
damper position sensor circuit.
Harness or connector between air inlet dam er osition sen-
sor and integration control and panel
Integration control and panel
WIRING DIAGRAM
DI3FG±10
Page 2552 of 4323
I28847
SG±TPI TPII20 Integration Control and Panel:
DI±2350
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2544 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check voltage between terminals TPI and SG±TPI of integration control and pan-
el.
PREPARATION:
Remove the integration control and panel with connectors still
connected.
CHECK:
(a) Turn the ignition switch to ON.
(b) Press the REC/FRS switch to change air inlet between
fresh and recirculation air, and measure the voltage be-
tween terminals TPI and SG±TPI of the integration con-
trol and panel when the air inlet damper control servomo-
tor operates.
OK:
FRS±REC SwitchVoltage
REC3.5 to 4.5 V
FRS0.5 to 1.5 V
HINT:
As the air inlet damper control servomotor is moved from the
REC side to the FRS side, the voltage decreases.
NG Go to step 2.
OK
Proceed to next circuit inspection shown in problem symptoms table (See page DI±2304). How-
ever, if DTC 32 or 42 is displayed, replace integration control and panel.