2001 TOYOTA SEQUOIA air conditioning

I07763
1
2
4
I07764
3
4
DI±2380
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2574 Author: Date:
2005 SEQUOIA (RM1146U)
4 Check power transistor.
PREPARATION:
Remove the power transistor (See page AC±84).
CHECK:
(a) Connect the positive (+) lead from the battery to terminal
1 through a 12 V ± 3.4 W test bulb and the negative (±)
lead to terminal 2.
(b) Check the test bulb lights up when another positive (+)
lead is connected to terminal 4 through a 12 V ± 3.4 W test
bulb.
OK:
Test bulb lights up.
CHECK:
Measure the resistance between terminals 3 and 4.
OK:
Resistance: 2.0 to 2.4 kW
NG Replace power transistor.
OK
5 Check harness and connector between integration control and panel and power
transistor, power transistor and body ground (See page IN±35).
NG Repair or replace harness or connector.
OK
Replace integration control and panel.

I28845
ECM
E5
E5G±BIntegration Control
and Panel
I22
ACT
AC1
8 25
24
L±W 2
21
5 MG CLT Relay
J3 J/C
15
IG4 C
C Engine Room J/B
2
2C4
2G
3
A3
A/C Magnetic Clutch
and Lock Sensor R±Y
IA1 LG±B5
4
Engine Room R/B No. 2
2 22 G±Y
MGC 5
I19 I22 ACT
AC1
IA5
R±Y1
L±W L±W
R±Y
L
L
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2381
2575 Author: Date:
2005 SEQUOIA (RM1146U)
Compressor Circuit
CIRCUIT DESCRIPTION
The integration control and panel outputs the magnetic clutch ON signal from terminal AC1 to the ECM.
When the ECM receives this signal, it sends a signal from terminal ACT and switches the A/C magnetic clutch
relay ON. This turns the A/C magnetic clutch on.
WIRING DIAGRAM
DIAA8±03

DI±2382
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2576 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Read value of hand±held tester.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand±held tester main SW ON.
CHECK:
Select the item below in the DATA LIST, and read the displays on the hand±held tester.
ENGINE AND ECT / ALL:
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic Note
A/C SIGA/C signal / ON or OFF
A/C SW Pushed: ON

A/C SW Released: OFF±
HINT:
Check with the engine running.
OK:
The display is as specified in the normal condition.
NG Go to step 8.
OK
2 Read value of hand±held tester.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand±held tester main SW ON.
CHECK:
Select the item below in the DATA LIST, and read the displays on the hand±held tester.
ENGINE AND ECT / ALL:
ItemMeasurement Item / Display
(Range)Normal ConditionDiagnostic Note
A/C MAG CLUTCHA/C magnet clutch / ON or OFF
A/C SW ON: ON

A/C SW OFF: OFF±
HINT:
Check with the engine running.
OK:
The display is as specified in the normal condition.
NG Replace ECM (See page SF±80).
OK

± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2383
2577 Author: Date:
2005 SEQUOIA (RM1146U)
3 Perform active test by hand±held tester.
PREPARATION:
(a) Connect the hand±held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand±held tester main SW ON.
CHECK:
Select the item below in the DATA LIST, and read the displays on the hand±held tester.
AIR CONDITIONING:
ItemTest Details / Display (Range)Diagnostic Note
A/C MAG CLUTCHMagnet clutch relay / OFF, ONOperating sound can be heard
HINT:
Check with the engine running.
OK:
The operation sound of the MG CLT relay can be heard.
NG Go to step 5.
OK
4 Check harness and connector between integration control and panel (ACT termi-
nal) and ECM (ACT terminal) (See page IN±35).
NG Repair or replace harness or connector.
OK
Proceed to next circuit inspection shown in problem symptoms table (See page DI±2304).

Z18060
15 2
3
12 3 5
I21361
3
DI±2384
± DIAGNOSTICSAIR CONDITIONING SYSTEM
2578 Author: Date:
2005 SEQUOIA (RM1146U)
5 Check magnetic clutch relay.
PREPARATION:
Remove the magnetic clutch relay from the engine room J/B.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:
Tester connectionConditionSpecified condition
3 ± 5Always10 kW or higher
3 ± 5
Voltage is applied
between terminals
1 and 2Below 1W (Battery
voltage is applied between
terminals 1 and 2)
NG Replace magnetic clutch relay.
OK
6 Check A/C magnetic clutch.
PREPARATION:
Disconnect the magnetic clutch connector.
CHECK:
Connect the positive (+) battery lead to the magnetic clutch con-
nector terminal 3.
OK:
Magnetic clutch is energized.
NG Replace A/C magnetic clutch.
OK
7 Check harness and connector between integration control and panel (MGC ter-
minal) and body ground (See page IN±35).
NG Repair or replace harness or connector.
OK
Replace integration control and panel.

I28847
AC1 Integration Control and Panel
I22
± DIAGNOSTICSAIR CONDITIONING SYSTEM
DI±2385
2579 Author: Date:
2005 SEQUOIA (RM1146U)
8 Check harness and connector between integration control and panel (AC1 termi-
nal) and ECM (AC1 terminal) (See page IN±35).
NG Repair or replace harness or connector.
OK
9 Check voltage between terminal AC1 of integration control and panel connector
and body ground.
PREPARATION:
(a) Disconnect the connector from the ECM.
(b) Remove the integration control and panel with the con-
nectors still connected.
(c) Start the engine and push the AUTO switch.
CHECK:
Measure the voltage between terminal AC1 of the integration
control and panel connector and body ground when the mag-
netic clutch is turned ON and OFF by the A/C switch.
OK:
Switch operationTester connectionSpecified condition
ONAC1 ± Body ground1.3 to 2.6 V
OFFAC1 ± Body ground3.7 to 4.5 V
NG Replace integration control and panel.
OK
Replace ECM (See page SF±80).

EM1X3±01
D13872
Hand±Held Tester
DLC3
CAN VIM
A23395
DLC3
TA C
SST
± ENGINE MECHANICALIDLE SPEED
EM±11
2590 Author: Date:
2005 SEQUOIA (RM1146U)
IDLE SPEED
INSPECTION
1. INITIAL CONDITIONS
(a) Engine at normal operating temperature
(b) Air cleaner installed
(c) All pipes and hoses of air induction system connected
(d) All accessories switched OFF
(e) All vacuum lines properly connected
(f) SFI system wiring connectors fully plugged
(g) iCorrect gnition timing
(h) Transmission in neutral
(i) Air conditioning switched OFF
2. INSPECT ENGINE IDLE SPEED
(a) When using a hand±held tester.
(1) Connect a hand±held tester to the Controller Area
Network Vehicle Interface Module (CAN VIM). Then
connect the CAN VIM to the Date Link Connector 3
(DLC3).
(2) Please refer to the hand±held tester operator's
manual for further details.
(3) Race the engine speed at 2,500 rpm for approx. 90
seconds.
(4) Check the idle speed.
Idle speed: 700 ± 50 rpm
(Transmission in neutral)
If the idle speed is not as specified, check the air intake system.
(5) Disconnect the hand±held tester and CAN VIM
from the DLC3.
(b) When not using a hand±held tester.
(1) Using SST, connect the tachometer probe to termi-
nal TAC of the DLC3.
SST 09843±18030
(2) Race the engine at 2,500 rpm for approx. 90 se-
conds.
(3) Check the idle speed.
Idle speed: 700 ± 50 rpm
(Transmission in neutral )
If the idle speed is not as specified, check the air intake system.

F06726Vacuum Hose
SR01X±08
SR±8
± STEERINGAIR CONTROL VALVE
3235 Author: Date:
2005 SEQUOIA (RM1146U)
AIR CONTROL VALVE
INSPECTION
1. TURN AIR CONDITIONING SWITCH OFF
2. CHECK IDLE±UP
(a) Start the engine and run it at idle.
(b) Fully turn the steering wheel.
(c) Check that the engine speed decrease when the vacuum
hose of the air control valve is pinched.
(d) Check that the engine speed increase when the hose is
released.