TOYOTA CAMRY 1999 Service Repair Manual

AIR CONDITIONING (AUTOMATIC A/C)
5. AIR CONDITIONING OPERATION
The A/C control assembly receives various signals, I.E., the engine RPM from the engine control module, out side air
temperature signal from the A/C ambient temp. sensor, coolant temperature from the engine control module and the lock
signal from the A/C compressor, etc.
When the engine is started and the A/C SW (A/C control assembly) is on, a signal is input to the A/C control assembly.
As a result, the ground circuit in A/C control assembly is closed and current flows from HEATER fuse to TERMINAL 1 of
the MG CLT relay to TERMINAL 2 to TERMINAL 3 of the diode (A/C) to TERMINAL 2 to TERMINAL MGCR of the A/C
control assembly to TERMINAL GND to GROUND, turning the MG CLT relay on, so that the magnetic clutch is on and the
A/C compressor operates.
At the same time, the engine control module. Detects the magnetic clutch is on and the A/C compressor operates.
If the A/C control assembly detects the following conditions, it stops the air conditioning:
*Evaporator outlet air is too low.
*There is a marked difference between the compressor speed and the engine speed.
*The refrigerant pressure is abnormally high or abnormally low.
*The engine speed is too low.
*Rapid acceleration occurs.
A3 A/C DUAL PRESSURE SW
4±1 : Open above approx. 2.0 kgf/cm2 (29 psi, 196 kpa) or 32 kgf/cm2 (464 psi, 3138 kpa)
A2
A/C MAGNETIC CLUTCH AND LOCK SENSOR
4±GROUND : Approx. 3.7 W
A34 (A), A35 (B) A/C CONTROL ASSEMBLY
B±GROUND : Always approx. 12 volts
IG+ ±GROUND : Approx. 12 volts with the ignition SW at ON position
HR ±GROUND : Approx. 12 volts with the ignition SW at ON position and do not turn the blower motor
Below 1 volts with the ignition SW at ON position and turn the blower motor
PSW±GROUND : Below 1 volts with the ignition SW at ON position
AC1±GROUND : Below 1 volts at start the engine, operate the compressor
+ OR MORE volts at start the engine, do not operate the compressor
BLW±GROUND : Below 1.5 volts with the ignition SW on and turn the blower motor
S5±SG :4±6 volts with the ignition SW at ON position
SG±GROUND : Always continuity
AMH±AMC :1.3±1.9 volts with the ignition SW off
AIF±GROUND : Approx. 12 volts with the FRESH SW on
AIR±GROUND : Approx. 12 volts with the RECIRC SW on
FACE±GROUND: Approx. 12 volts with the FACE SW on
DEF±GROUND : Approx. 12 volts with the DEF SW on
GND±GROUND : Always continuity
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
A226 (1MZ±FE)A3630F826 (1MZ±FE)
A326 (1MZ±FE)A3730J131
A1330A3830J1131
A2030A3930J27A31
A3026 (1MZ±FE)B330J28B31
A3330B830J2931
A34A30D330J3231
A35B30E830
: RELAY BLOCKS
CodeSee PageRelay Blocks (Relay Block Location)
124Engine Room R/B No.1 (Engine Compartment Left)
SERVICE HINTS

: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CodeSee PageJunction Block and Wire Harness (Connector Location)
1R
1V20Cowl Wire and Instrument Panel J/B (Lower Finish Panel)
1W
()
2C22Engine Room Main Wire and Engine Room J/B No.2 (Engine Compartment Left)
2J22Cowl Wire and Engine Room J/B No 2 (Engine Compartment Left)2K22Cowl Wire and Engine Room J/B No.2 (Engine Compartment Left)
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CodeSee PageJoining Wire Harness and Wire Harness (Connector Location)
EB236 (1MZ±FE)Cowl Wire and Engine Room Main Wire (Under the Engine Room J/B No.2)
IG140Instrument Panel Wire and Cowl Wire (Lower Finish Panel)
IK1
IK242Engine Room Main Wire and Cowl Wire (Right Kick Panel)
IK3
g(g)
: GROUND POINTS
CodeSee PageGround Points Location
EB36 (1MZ±FE)Left Radiator Side Support
IG40Instrument Panel Brace LH
II40Cowl Side Panel RH
: SPLICE POINTS
CodeSee PageWire Harness with Splice PointsCodeSee PageWire Harness with Splice Points
I742Cowl WireI942Cowl WireI842Cowl WireI1042Cowl Wire
12
X41



412123456712
12341

34X67891011
13
14 15
16 17 18 19 20 X X 23XX26
8910X X234
56 7
13 X14X16
12
1X3X5671
2345
12
X2
XXX6
23 GRAY BLACKDARK GRAY
BLACKBLACK BLACK
BLACKORANGE
A2 A3 A13 A20 A30
A33 A34 (A) A35 (B) A36 A37
A38 A39 B3 B8 D3
2 1

AIR CONDITIONING (AUTOMATIC A/C)
X

XX



13 14 X X



X X

X
25 X X

X
X

X
27
1AA



AA





AA
AAAA











FF



















FFFF


A A
AA












DD



GRAY
E8 F8 J1 J11
J27 (A) J28 (B) J29 J32
(Hint : See Page 7)(Hint : See Page 7)
(Hint : See Page 7)
(Hint : See Page 7)
(Hint : See Page 7) (Hint : See Page 7)

MEMO

AIR CONDITIONING (MANUAL A/C)
1 1
11 1
1261
3584
IG EB215
4
23
1 HI M2 M11W 2
I 3L±B
B±W
L±B
B±WL±W W± B
W±BL±R W± B
L±W
10A
HEATER
1
HTR
RELAY
BLOWER RESISTOR
BLOWER
MOTOR
B±W
L±B
L±O
BLOWER SWOFF FROM POWER SOURCE SYSTEM (
SEE PAGE 50)
LO B 3B 4
B 512
1 1 EB131R 3
2C 92K 5
23 1511
11A
AAA
3
JUNCTION
CONNECTOR J11JUNCTION
CONNECTOR J32 FUSIBLE
LINK BLOCK F 8
L±R
L±B L±B
L±B L±B
B±W(
*2) L±W(
*1) L±Y(
*2) B±W
L±B
L±B L±B
L±RTO FAN NO. 3 RELA Y MG CLT
RELAY
10A A/C
EB 2 1EB12
L±R
W±B
W±B
L±B
W± B
W±BL±B W±B W±BL±R L±W(
*1) L±Y(
*2) B±WL±B
W±B
50A HTR
(
*1)
(
*1)
A
A
A M

M
CONTROL
CIRCUIT
AIR VENT MODE CONTROL SERVO MOTOR A20* 2 : 5S±FE * 1 : 1MZ±FE
IK27 4 5 6 7 8 1 2 3
DD3
12345
25 1
6
7D2
A/C SW A14 DIODE
(
A/C) D 3
JUNCTION
CONNECTOR J12 L±B
B±W
L±Y(
*2)
L±W(
*1)
L±R
W± B
W± B
L±B
W± B
L±OB±L
L±RL L±W W± BR±BL±R
GND FACE B/L FOOT F/D DEFDEF F/D FOOT B/L
FACE HEATER CONTROL SW H 9
L±Y
(
*1)L±Y(
*2) L±Y(
*1) B±WL±B
W±B
R±W
(
*1)
R±B
R±B
R±W
(
*2)
R±W
(
*1) R±BL±R
OFF
ON DEF F/ D FOOT B/L FACE
IG
GNDL±R
A
B(
*1) (
*1) W± B

AIR CONDITIONING (MANUAL A/C)
A/C EVAPORATOR
TEMP. SENSOR A13
EC II2 3 II2 1II36 II3 10IK2 9IK210
C 18(
*4)
B 9 B 10 A 10 A 21 A 13 A 15B D
A F 1
4
IK2 2
BF
A 13 9 7 1 4 8 5102 1
BB 12 214
F 4
A F A/C AMPLIFIER A1 2A/C MAGNETIC
CLUTCH AND
LOCK SENSOR A 2
A/C DUAL
PRESSURE SW A 3
JUNCTION CONNECTOR J1 2
JUNCTION CONNE CTOR J23JUNCTION CONNECTOR J2 9 JUNCTION CONNECTOR
ENGINE CONTROL MODULE L±B
B±W
L±Y(
*1)
L±Y(
*2)
G G
(
*1)
G
(
*2)B±W
MGC +BLOCK
GND L±A/C S±A/C IGN AC1 ACT TH SG
W± B
R±W
(
*1)
R±B
R±B
R±W
(
*2)1
2
W±B
R±W
(
*1)
R±B
B±O
(
*1)
B±Y
(
*1)
L±W
(
*1)
W±R
(
*1) L±W
(
*2)
BR
(
*2)
W± R
(
*1) LG±B
(
*1)
L±R
BR
W±L
(
*2) (
*2) (
*2)
LOCK P RS MGC A/C S W TACH A/C ACT THR E2 LOCK INBR
(
*2)BR
(
*2)BR
(
*2)W± L
(
*2)
W±R(
*1)
BR(
*2)W±L
(
*1)
W± L
BR(
*2) W±R(
*1) B±O
(
*1) R±B
(
*2) L±Y
(
*2) G
(
*2)
(
*1) W± B
(
*1) W±B
(
*1) R±B
B
B
JUNCTION
CONNECTOR J 8B J27 A , J28
A 20 A19 A21 A10 B11 B9C19(
*3) B 27 B25 B13(
*1)
B E 7 A , E 8 C, E 9* 1 : 1MZ±FE
* 2 : 5S±FE* 3 : 5S±FE W/ ENGINE IMMOBILISER
* 4 : 5S±FE W/O ENGINE IMMOBILISER

Current always flows from the HTR fuse to TERMINAL 1 of the HTR relay. When the ignition SW is turned on, the current
from the HEATER fuse flows to TERMINAL 6 of the air vent mode control servo motor, to the MG CLT relay (Coil side) to
TERMINAL MGC of the A/C amplifier (1MZ±FE) or TERMINAL MGC of the engine control module (5S±FE), to TERMINAL 1
of the A/C dual pressure SW to TERMINAL 4 to TERMINAL +B of the A/C amplifier (1MZ±FE) or TERMINAL PRS of the
engine control module (5S±FE), current also to the HTR relay (Coil side) to TERMINAL 3 of the blower SW.
1. AIR VENT MODE CONTROL SERVO MOTOR OPERATION
When the damper is in FACE position and B/L mode on the heater control SW is selected, current flows from TERMINAL 7
of the heater control SW to TERMINAL 2 of the air vent mode control serve motor so that a signal that the ground circuit is
activated is input into TERMINAL B of the control circuit inside the air vent mode control servo motor. Simultaneously, a
signal that the ground circuit is not activated is input into TERMINAL A of the control circuit inside the servo motor. These two
signals activate the control circuit so that current flows from the HEATER fuse to the servo motor, causing the servo motor to
operate and the damper to move to B/L position. When the damper reaches B/L position. A ground cut signal is input into
TERMINAL B of the control circuit, the control circuit operates, the servo motor stops rotating and the damper stops at B/L.
When another mode position is selected, input of signals into TERMINAL A and TERMINAL B of the control circuit that
ground is made or not (as explained above) activates the control circuit and moves the serve motor to the desired position.
2. AIR CONDITIONING OPERATION
When the blower SW is on, current flows from the HEATER fuse to the HTR relay (Coil side) to TERMINAL 3 of the blower
SW to TERMINAL 1 to GROUND, activating the HTR relay. This causes current to flow from the HTR fuse to the HTR relay
(Point side) to A/C fuse to TERMINAL 2 of the A/C SW. If the A/C SW is turned on at this time, a signal is input into the A/C
amplifier (1MZ±FE) or engine control module (5S±FE). This activates the A/C amplifier (1MZ±FE) or engine control module
(5S±FE) and MG CLT relay so that current flows from the HEATER fuse to the MG CLT relay (Point side) to A/C magnetic
clutch. Causing The compressor to operate.
When blower SW is on and heater control SW is at DEF position, it causes A/C to run whether A/C SW is on or not.
HTR RELAY [R/B NO.1]
1±2 : Closed with the ignition SW on and the blower SW on
MG CLT RELAY [R/B NO.1]
5±3 : Closed with the ignition SW on, the blower SW on and the A/C SW on or the heater control SW at DEF position
A3 A/C DUAL PRESSURE SW
1±4 : Open with pressure 2.0 kgf/cm
2 (29 psi, 196 kpa) or above 32 kgf/cm2 (464 psi, 3138 kpa)
B4
BLOWER RESISTOR
6±1 : Approx. 0.62 W
1±3 : Approx. 1.46 W
2±6 : Approx. 0.38 W
: PARTS LOCATION
CodeSee PageCodeSee PageCodeSee Page
A226 (1MZ±FE)B430J831A228 (5S±FE)B530J1131
A326 (1MZ±FE)D326 (1MZ±FE)J1231A328 (5S±FE)E7A30J2331
A1230E8B30J27A31
A1330E9C30J28B31
A1430F826 (1MZ±FE)J2931
A2030F828 (5S±FE)J3231
B330H930
: RELAY BLOCKS
CodeSee PageRelay Blocks (Relay Block Location)
124Engine Room R/B No.1 (Engine Compartment Left)
SYSTEM OUTLINE
SERVICE HINTS

AIR CONDITIONING (MANUAL A/C)
: JUNCTION BLOCK AND WIRE HARNESS CONNECTOR
CodeSee PageJunction Block and Wire Harness (Connector Location)
1R20Cowl Wire and Instrument Panel J/B (Lower Finish Panel)1W20Cowl Wire and Instrument Panel J/B (Lower Finish Panel)
2C22Engine Room Main Wire and Engine Room J/B No.2 (Engine Compartment Left)
2K22Cowl Wire and Engine Room J/B No.2 (Engine Compartment Left)
: CONNECTOR JOINING WIRE HARNESS AND WIRE HARNESS
CodeSee PageJoining Wire Harness and Wire Harness (Connector Location)
EB136 (1MZ±FE)EB138 (5S±FE)Cowl Wire and Engine Room Main Wire (Under the Engine Room J/B No 2)
EB236 (1MZ±FE)Cowl Wire and Engine Room Main Wire (Under the Engine Room J/B No.2)
EB238 (5S±FE)
II242Engine Wire and Cowl Wire (Under the Blower Motor)II342Engine Wire and Cowl Wire (Under the Blower Motor)
IK242Engine Room Main Wire and Cowl Wire (Right Kick Panel)
: GROUND POINTS
CodeSee PageGround Points Location
EB36 (1MZ±FE)Left Radiator Side SupportEB38 (5S±FE)Left Radiator Side Support
EC38 (5S±FE)Intake Manifold
IG40Instrument Panel Brace LH
: SPLICE POINTS
CodeSee PageWire Harness with Splice PointsCodeSee PageWire Harness with Splice Points
I342Cowl Wire
12
X4
X 4 X 2 1
78910X12 145
13
12
12

5
123456712
12
3XX61X3
45


8
23 GRAY BLACK ORANGE
A13 A14
A20 B3 B4 B5
ORANGE
1



4
A2 A3 A12
D3

10









19 20 21

X

XX



13
XX



X X

X
25 X X

X
X

X
27









9
11













910


X






X











X
X9







112 3
45678






X


10


13

15




21

1


















X
18














BBB



B B






DDDBAA AA
AAAAAAAAA
AAAA



















FFFF











FF







DD







A A
AA




(* 1) (* 2) (1MZ±FE)
(* 1) DARK GRAY (* 2) (* 1) DARK GRAY
(* 2)
F8 H9GRAY
(Hint : See Page 7) * 1 : 5S±FE w/ Engine Immobiliser System
* 2 : 5S±FE w/o Engine Immobiliser System
(Hint : See Page 7)(Hint : See Page 7)
(Hint : See Page 7)
(Hint : See Page 7)
(Hint : See Page 7)(Hint : See Page 7)(Hint : See Page 7)GRAY
J29 J28 (B)J27(A) J23
BLACKJ11E7 (A) E7 (A) E8 (B)
E8 (B)
E8 (B)E9 (C)
E9 (C)J8
J12
J32