2001 TOYOTA SEQUOIA Page 18

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

± 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.

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.

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.

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.

I25201
RECFRS
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2351
2545 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check air inlet damper position sensor.
PREPARATION:
Remove the air inlet servomotor (See page AC±49).
CHECK:
Measure the resistance between terminals 3 and 2 of the air in-
let servomotor connector.
OK:
Resistance : 4.2 to 7.8 kW
CHECK:
While operating the air inlet servomotor, following the proce-
dure on page DI±2358, measure the resistance between termi-
nals 3 and 2 of the air inlet servomotor connector.
OK:
Resistance
Damper PositionResistance
REC side3.1 to 5.8 kW
FRS side0.8 to 1.6 kW
HINT:
As the air inlet servomotor moves from the REC side to the FRS
side, the resistance decreases.
NG Replace air inlet damper servomotor.
OK
3 Check harness and connectors between air inlet damper position sensor and in-
tegration control and panel (See page IN±35).
NG Repair or replace harness or connector.
OK
Replace integration control and panel.

I28847
RrSG
RrTPI21 Integration Control and Panel:
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2353
2547 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check voltage between terminals RrTP and RrSG 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 water valve
servomotor and measure the voltage between terminals
RrTP and RrSG of the integration control and panel con-
nector 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 37 or 47 is displayed, replace integration control and panel.

I28852
HOTCOOL
4
532 4
5
2
3
1
1
DI±2354
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2548 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check water valve damper position sensor.
PREPARATION:
Remove the water valve servomotor (See page AC±42).
CHECK:
Measure the resistance between terminals 1 and 2 of the water
valve servomotor connector.
OK:
Resistance : 4.2 to 7.8 kW
CHECK:
While operating the water valve servomotor, following the pro-
cedure on page DI±2361, measure the resistance between ter-
minals 2 and 3 of the water valve servomotor connector.
OK:
PositionResistance
Max. cool0.8 to 1.6 kW
Max. hot3 to 5.6 kW
HINT:
As the water valve servomotor moves from the cool side to the
hot side, the resistance decreases.
NG Replace water valve servomotor.
OK
3 Check harness and connector between water valve 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.