TOYOTA SIENNA 2007 Service Repair Manual

AC–128AIR CONDITIONING – AIR CONDITIONING SYSTEM (for Automatic Air Conditioning Sys-
tem)
AC
DESCRIPTION
The blower motor is operated by signals from the A/C amplifier. Blower motor speed signals are
transmitted by changes in the Duty Ratio.
Duty Ratio
The duty ratio is the ratio of the period of continuity in one cycle. For example, if A is the period of
continuity in one cycle, and B is the period of non-continuity, then Duty Ratio = A/(A+B) x 100 (%).
Blower Motor Circuit
E145209E01
E145208E01

AIR CONDITIONING – AIR CONDITIONING SYSTEM (for Automatic Air Conditioning Sys-
tem)AC–129
AC
WIRING DIAGRAM
INSPECTION PROCEDURE
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the
intelligent tester main switch on.
(c) Select the item below in the DATA LIST, and read the
display on the intelligent tester.
DATA LIST / AIR CONDITIONER
OK:
The display is as specified in the normal condition
column.
NG
OK
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the
intelligent tester main switch on.
1READ VALUE OF INTELLIGENT TESTER
C119463E03
Tester Display Measurement Item/Range Normal Condition Diagnostic Note
BLOWER LEVELBlower motor speed level / min.:
Level 0, max.: Level 31Changes depending on blower
level-
Go to step 2
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
2PERFORM ACTIVE TEST BY INTELLIGENT TESTER

AC–130AIR CONDITIONING – AIR CONDITIONING SYSTEM (for Automatic Air Conditioning Sys-
tem)
AC
(c) Select the item below in the ACTIVE TEST and then
check that the blower motor operates.
ACTIVE TEST / AIR CONDITIONER
OK:
The blower motor operates and the blower level
changes.
NG
OK
(a) Enter the actuator check mode (See page AC-15).
(b) Press the DEF switch to change to the step operation.
(c) Check the air flow level by hand.
OK:
The blower level changes in accordance with each
display code.
NG
OK
Tester Display Test Part Control Range Diagnostic Note
BLOWER LEVEL Blower motor speed level min.: Level 0, max.: Level 31 -
Go to step 3
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
3PERFORM ACTUATOR CHECK
Display Code Blower Level
00
11
217
317
417
517
617
717
817
931
Go to step 4
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE

AIR CONDITIONING – AIR CONDITIONING SYSTEM (for Automatic Air Conditioning Sys-
tem)AC–131
AC
(a) Remove the blower motor.
(b) Disconnect the connector from the blower motor.
(c) Connect the positive (+) lead from the battery to terminal
2 and the negative (-) lead to terminal 1, and check that
the motor operates.
OK:
Blower motor operates smoothly.
NG
OK
(a) Disconnect the connector from the blower motor.
(b) Disconnect the connector from the blower motor
controller.
(c) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
4INSPECT BLOWER MOTOR
E147349E01
REPLACE BLOWER MOTOR
5CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - BLOWER MOTOR
CONTROLLER)
E147584E01
Tester Connection Condition Specified Condition
B2-2 - B3-2 (VM) Always Below 1
B2-2 - Body ground Always 10 k or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR

AC–132AIR CONDITIONING – AIR CONDITIONING SYSTEM (for Automatic Air Conditioning Sys-
tem)
AC
OK
(a) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
(a) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
OK
6CHECK HARNESS AND CONNECTOR (BLOWER MOTOR - BODY GROUND)
E145472E02
Tester Connection Condition Specified Condition
B2-1 - Body ground Always Below 1
REPAIR OR REPLACE HARNESS OR
CONNECTOR
7CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROLLER - BODY
GROUND)
E147376E01
Tester Connection Condition Specified Condition
B3-6 (GND) - Body
groundAlways Below 1
REPAIR OR REPLACE HARNESS OR
CONNECTOR

AIR CONDITIONING – AIR CONDITIONING SYSTEM (for Automatic Air Conditioning Sys-
tem)AC–133
AC
(a) Measure the voltage according to the value(s) in the
table below.
Standard voltage
NG
OK
(a) Disconnect the connector from the A/C amplifier.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
NG
8CHECK HARNESS AND CONNECTOR (BLOWER MOTOR CONTROLLER - BATTERY)
E147376E02
Tester Connection Condition Specified Condition
B3-1 (+B) - Body ground Always 11 to 14 V
REPAIR OR REPLACE HARNESS OR
CONNECTOR
9CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BLOWER MOTOR
CONTROLLER)
E147585E01
Tester Connection Condition Specified Condition
A9-6 (BLW) - B3-3 (SI) Always Below 1
A9-6 (BLW) - Body
groundAlways 10 k or higher
REPAIR OR REPLACE HARNESS OR
CONNECTOR

AC–134AIR CONDITIONING – AIR CONDITIONING SYSTEM (for Automatic Air Conditioning Sys-
tem)
AC
OK
(a) Reconnect the connector to the A/C amplifier.
(b) Reconnect the connector to the blower motor controller.
(c) Reconnect the connector to the blower motor.
(d) Measure the waveform between terminal A9-6 (BLW) of
the A/C amplifier and body ground.
OK:
Waveform is as shown in the illustration.
HINT:
Waveform varies with the blower level.
NG
OK
10INSPECT A/C AMPLIFIER
E147476E01
E103396E01
Item Contents
Tool Setting 1 V/DIV., 500
s/DIV.
Vehicle ConditionIgnition switch: ON
Blower switch: LO
REPAIR OR REPLACE HARNESS OR
CONNECTOR
REPLACE BLOWER MOTOR CONTROLLER

AIR CONDITIONING – AIR CONDITIONING SYSTEM (for Automatic Air Conditioning Sys-
tem)AC–135
AC
DESCRIPTION
When the A/C amplifier is turned on, a magnetic clutch ON signal is sent from the MGC terminal of the A/
C amplifier. Then, the MG CLT relay turns on to operate the magnetic clutch.
WIRING DIAGRAM
INSPECTION PROCEDURE
(a) Use the intelligent tester to check if the CAN
communication system is functioning normally.
Result
Air Conditioning Compressor Magnetic Clutch Circuit
1CHECK CAN COMMUNICATION SYSTEM
E124490E08
Result Proceed to
CAN DTC is not output A
CAN DTC is output B

AC–136AIR CONDITIONING – AIR CONDITIONING SYSTEM (for Automatic Air Conditioning Sys-
tem)
AC
B
A
(a) Use the intelligent tester to check if the multiplex
communication system is functioning normally.
Result
B
A
(a) Connect the intelligent tester to the DLC3.
(b) Turn the ignition switch to the ON position and turn the
intelligent tester main switch on.
(c) Select the item below in the ACTIVE TEST and then
check that the relay operates.
ACTIVE TEST / AIR CONDITIONER:
OK:
Magnetic clutch relay operates.
NG
OK
(a) Remove the HTR fuse from the driver side junction
block.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
(c) Reconnect the HTR fuse to the driver side junction block.
NGGO TO CAN COMMUNICATION SYSTEM
2CHECK MULTIPLEX COMMUNICATION SYSTEM
Result Proceed to
MPX DTC is not output A
MPX DTC is output B
GO TO MULTIPLEX COMMUNICATION
SYSTEM
3PERFORM ACTIVE TEST BY INTELLIGENT TESTER
Tester Display Test Part Control Range Diagnostic Note
A/C MAG CLUTCH Magnetic clutch relay OFF, ON -
Go to step 4
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
4INSPECT FUSE (HTR)
Tester Item Condition Specified Condition
HTR fuse Always Below 1
REPLACE FUSE (HTR)

AIR CONDITIONING – AIR CONDITIONING SYSTEM (for Automatic Air Conditioning Sys-
tem)AC–137
AC
OK
(a) Remove the MG CLT relay from the No. 3 relay block.
(b) Measure the resistance according to the value(s) in the
table below.
Standard resistance
(c) Install the MG CLT relay to the No. 3 relay block.
NG
OK
(a) Disconnect the connector from the A/C amplifier.
(b) Measure the voltage according to the value(s) in the
table below.
Standard voltage
NG
OK
5INSPECT RELAY (MG CLT)
B060778E04
Tester Connection Specified Condition
3 - 5 10 k
or higher
3 - 5Below 1
(when battery voltage is applied to terminals 1 and 2)
REPLACE RELAY (MG CLT)
6CHECK HARNESS AND CONNECTOR (A/C AMPLIFIER - BATTERY)
E143742E44
Tester Connection Condition Specified Condition
A9-5 (MGC) - Body
groundIgnition switch: OFF Below 1 V
A9-5 (MGC) - Body
groundIgnition switch: ON 11 to 14 V
REPAIR OR REPLACE HARNESS OR
CONNECTOR