2004 LAND CRUISER (EWD548U)
358Air Conditioning (Front)
R- L(
*1)
W- BM FACE B/L FOOT FOOT/
DEFDEF
- + A 16FACE
A 15B/L
A 14FOOT
A 13F/D
A 12DEF
GR
BR- W
W
P- L
B- W
1234 5
IF 2D 237 6
3N 22
3N 11
R- L R- L
W- B (
*1)
W- B
A26AC 12GND
2D 2A
W- B W- BW- B
AC 17VER2
W- B
AC 15VER4
W- B
AC 14VER5
W- B
J11C 8PSW
5A 5
5D 18
1B 46
1A 46
1
4
Dual
A 4
L- W L- W L- W W- B
A45(
A)
, A46(
B)
, A47(
C)
Pressure SW Air Vent Mode Contr ol Servo MotorA/C Control Assembly
Junction Connector
* 1 : w/ Navigation System
(
*1)
2004 LAND CRUISER (EWD548U)
361
C 11+B10A
ECU- B2
3Q 71 3K19
18 4A
4A 9
19 2E
2Q 22
L- W L- W SB
L- WSB
4A 17
4A 8
3E 26
3E 21
W- L W- L W- L
R
A45(
A)
, A46(
B)
, A47(
C)
TC
3C
5
ACAN
B 94F 10
4C 2
W- B W- B
VER1
18 C
IV4 18 IV419 IV415 IV416 B 10FRCID FRCLK
1B
IV4 17FRCSD
2B
BKGND CID CLK CSD +B IG
B
W
R (
Shielded)
WB
B- W B- WL- W W- B
10A
ECU- IG2 Fr om Power Source System (
See Page 94)
3K 35
B
W
RW- B W- B W- B
A32
(
Shielded)
* 2 : w/o Navigation System * 1 : w/ Navigation System
A/C Amplifier (
Rear) A/C Control Assembly
Body ECU
2 1 19 20 18 22 B FA H
B F(
*2) A H(
*1)
A H(
*1)
B F(
*2) A H
B F
Junction
Connector J23(
B)
, J25(
A)
2004 LAND CRUISER (EWD548U)
362Air Conditioning (Front)
1. Heater Blower Operation
Manual operation
When the blower speed is set ant any speed by the blower control SW, the A/C control assembly sends a signal to the
blower motor controller, and controls the blower motor speed.
Auto operation
When the auto SW is operated, the A/C control assembly sends signals to the blower motor controller, according to the
signals from respective sensors, commands from the temperature SW etc., and controls the blower motor automatically.
2. Air Inlet Control Servo Motor Control
When the FRESH/RECIRC select SW is switched to RECIRC, the motor in the air inlet control servo motor rotates to move
the damper to the RECIRC side. The damper position is recognized by the A/C control assembly TERMINAL TPI, and
rotates the motor until the damper reaches its position.
When the FRESH/RECIRC select SW is switched to FRESH, the motor in the air inlet control servo motor rotates to move
the damper to the FRESH side. The damper position is recognized by the A/C control assembly TERMINAL TPI, and rotates
the motor until the damper reaches its position.
When the FRESH/RECIRC select SW is set to auto, the exhaust gas sensor in the engine room detects the ingredient of the
exhaust emission, and switches the FRESH/RECIRC mode automatically.
3. Air Vent Mode Control Servo Motor
When the mode select SW in the A/C control assembly is pushed, a signal is sent from the A/C control assembly, and
activates the air vent mode control servo motor. This causes the servo motor to rotate to the position selected using the
mode select SW (FACE, BI-LEVEL, FOOT, FOOT/DEF, DEF), and moves the damper.
4. Air Mix Control Servo Motor
When the temperature control SW in the A/C control assembly is pushed, a signal is sent from the A/C control assembly, and
activates the air mix control servo motor. The motor and damper is moved until it reaches the temperature set by the
temperature control SW.
5. Air Conditioning Operation
The A/C control assembly receives various signals, i. e., the engine RPM from the crankshaft position sensor, outlet
temperature from the A/C ambient temp. sensor, coolant temperature from the engine coolant temp. sensor, and the lock
signal from the A/C compressor, etc. When the engine is started and the A/C SW is turned on, a signal is sent to the A/C
control assembly. As a result, the magnetic clutch is turned on and operates the compressor.
In addition, when the engine control module detects that the magnetic clutch is on and the A/C compressor is operating, it
controls the engine in the direction to avoid lowering the engine RPM during A/C operation.
When any of the following signals are sent to the A/C control assembly, the A/C is turned off.
*Coolant temp. is high.
*Outlet air temp. is low.
*Large difference between the engine speed and compressor speed.
*The refrigerant pressure is abnormally high or low.
A45 (A), A47 (C) A/C Control Assembly
(C)11-Ground : Always approx. 12 volts
(C)22-Ground : Approx. 12 volts with ignition SW at ON or ST position
(A)27-Ground : Approx. 12 volts with ignition SW at ON or ST position (w/o navigation system)
(C) 12, (C) 14, (C) 15, (C) 17, (C) 18-Ground : Always continuity
C28 Center Cluster Integration Panel (w/ Navigation System)
2-Ground : Approx. 12 volts with ignition SW at ON or ST position
16-Ground : Always continuity
System Outline
Service Hints
2004 LAND CRUISER (EWD548U)
367
C 18VER1
4F 10
4C 2
IV4 18
W- B W- B
IV4 19 IV415 IV416 IV417 B 10FRCID
B 1FRCLK
B 2 FRCSD
(
Shielded)
B
W
R
10A
ECU- B2 From Power Source System (
See Page 94)
3Q 71 3K19 C 11+B
L- W L- W
94A 18 4A
2E 19
2Q 22
SB
C 22IG15A
A/C
2D 6
R- L
R- L W- B
B14
W- B
LG- R
BKA45(
A)
, A46(
B)
, A47(
C) L- B
L- B
L- W
W- B
R
W
B
W- B
LG- R W- B
L- W
W- B
W- B
SB
A/C Control Assembly
R WB (
Shielded) Junction
Connector J23(
B)
, J25(
A)
B F(
*2) A H(
*1)
B FA H
A H
B FA H(
*1)
B F(
*2)
* 2 : w/o Navigation System * 1 : w/ Navigation System
2004 LAND CRUISER (EWD548U)
370Air Conditioning (Rear)
MCool Warm
GND PT VZ MHOT MCOOL 3K 39
BW1 1
B- W
10A
ECU- IG2
3K 35 From Power Source System
(
See Page 94)
R- L
B- W
BW1 3A 7TER
Y Y
2 1
BW1 4
Y- G
R21
A 9SG1
BL1 7
BD3 2
B- W
Y- G
Y- G
BL4 7
BD3 16
GR - R
BL4 5
BD3 15
R- Y
BL4 4
BD3 14
Y
BL4 3
BD3 13
W- L
A 6TPH
A 5S51
A 12MHR
A 11MCR
351 2
R 9 2
GR- R
R- Y
Y
W- L GR - R
R- Y
Y
W- L Y- G Y- G
D
DD A
Y- GY- G Y- G
Y- G
IG1
Y- G A32(
A)
, A33(
B)
, A34(
C)
J224 A/C Amplifier (
Rear)
Rear Air Mix Control Servo Motor
Rear Evaporator Temp. Sensor
Junction
Connector
Junction
Connector J23(
B)
, J25(
A) (
*2) (
*1)
B CA C
A C(
*1)
B C(
*2) A C
B C
* 2 : w/o Navigation System * 1 : w/ Navigation System
2004 LAND CRUISER (EWD548U)
93 SYSTEM CIRCUITS H
2004 LAND CRUISER
ELECTRICAL WIRING DIAGRAM
SYSTEM CIRCUITS
Page
Air Conditioning (Front) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
356
Air Conditioning (Rear) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 366
Auto Antenna . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 322
Automatic Glare-Resistant EC Mirror with Compass . . . . . . . . . . . . . . . . . . . 304
Automatic Light Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164
Back-Up Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162
Center Differential Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 246
Charging . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Cigarette Lighter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 204
Combination Meter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 350
Cruise Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 222
Door Lock Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260
Electronically Controlled Transmission and A/T Indicator . . . . . . . . . . . . . . . 212
Engine Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108
Engine Immobiliser System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124
Front Fog Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 132
Front Wiper and Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196
Garage Door Opener . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Headlight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
Horn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 208
Ignition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100
Illumination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142
Interior Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148
Key Reminder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 316
Light Auto Turn Off . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166
Mirror Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 314
Moon Roof . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 256
Multi-Display (w/o Navigation System) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 348
Multiplex Communication System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172
Multiplex Communication System (Communication Bus) . . . . . . . . . . . . . . . 168
Navigation System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
Power Outlet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Power Rear Quarter Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 306
Power Seat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 294
Power Source . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
Power Tilt and Power Telescopic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 298
Power Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 250
Radio and Player (w/ Navigation System) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 324
Radio and Player (w/o Navigation System) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 330
Rear Window Defogger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 312
Rear Wiper and Washer . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200
Remote Control Mirror . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 302
Seat Belt Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 320
Seat Heater . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 308
Shift Lock . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 244
SRS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 237
Starting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
Stop Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156
Taillight . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138
Theft Deterrent . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 282
TOYOTA Parking Assist (Rear View Monitor) . . . . . . . . . . . . . . . . . . . . . . . . . . . 336
Trailer Towing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158
Turn Signal and Hazard Warning Light . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134
VSC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 228
Wireless Door Lock Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 270
IN04S-46
- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMSIN-25
25 Author: Date:
2004 LAND CRUISER (RM1071U)
HOW TO TROUBLESHOOT ECU CONTROLLED SYSTEMS
GENERAL INFORMATION
A large number of ECU controlled systems are used in the LAND CRUISER. In general, the ECU controlled
system is considered to be a very intricate system requiring a high level of technical knowledge and expert
skill to troubleshoot. However, the fact is that if you proceed to inspect the circuits one by one, troubleshoot-
ing of these systems is not complex. If you have adequate understanding of the system and a basic knowl-
edge of electricity, accurate diagnosis and necessary repair can be performed to locate and fix the problem.
This manual is designed through emphasis of the above standpoint to help service technicians perform ac-
curate and effective troubleshooting, and is compiled for the following major ECU controlled systems:
The troubleshooting procedure and how to make use of it are described on the following pages.
SystemPage
1. EngineDI-1
2. Automatic TransmissionDI-358
3. ABS & Vehicle Stability Control (VSC) & Brake Assist (BA) SystemDI-502
4. Power Tilt and Power Telescopic Steering ColumnDI-656
5. Supplemental Restraint SystemDI-690
6. Wireless Door Lock Control SystemDI-936
7. Theft Deterrent SystemDI-953
8. Cruise Control SystemDI-979
9. Engine Immobiliser SystemDI-1002
10.Body Control SystemDI-1038
11. Driver Door Control SystemDI-1089
12.Multiplex Communication SystemDI-1 127
13.Navigation SystemDI-1 151
14.Rear View Monitor SystemDI-1268
15.Air Conditioning SystemDI-1300
FOR USING OBD II SCAN TOOL OR TOYOTA HAND-HELD TESTER
Before using the scan tool or tester, the scan tool's instruction book or tester's operator manual should
be read thoroughly.
If the scan tool or tester cannot communicate with ECU controlled systems when you have connected
the cable of the scan tool or tester to DLC3, turned the ignition switch ON and operated the scan tool,
there is a problem on the vehicle side or tool side.
(1) If communication is normal when the tool is connected to another vehicle, inspect the diagnosis
data link line (Busline) or ECU power circuit of the vehicle.
(2) If communication is still not possible when the tool is connected to another vehicle, the problem
is probably in the tool itself, so perform the Self Test procedures outline in the Tester Operator's
Manual.
DIAGNOSTIC TROUBLE CODE CHECK PROCEDURE
Diagnostic Trouble
Code Check (Make a
note of and then clear)Confirmation
of SymptomsDiagnostic Trouble
Code CheckProblem Condition
Diagnostic Trouble
Code DisplayProblem symptoms
existSame diagnostic
trouble code is
displayedProblem is still occurring in the diagnostic
circuit
Normal code is
displayedThe problem is still occurring in a place
other than in the diagnostic circuit
(The diagnostic trouble code displayed
first is either for a past problem or it is a
secondary problem)
No problem
symptoms existThe problem occurred in the diagnostic
circuit in the past
Normal Code DisplayProblem symptoms
existNormal code is
displayedThe problem is still occurring in a place
other than in the diagnostic circuit
No problem
symptoms existNormal code is
displayedThe problem occurred in a place other
than in the diagnostic circuit in the past
IN-28- INTRODUCTIONHOW TO TROUBLESHOOT ECU CONTROLLED
SYSTEMS
28 Author: Date:
2004 LAND CRUISER (RM1071U)
2. SYMPTOM CONFIRMATION AND DIAGNOSTIC TROUBLE CODE CHECK
The diagnostic system in the LAND CRUISER fulfills various functions. The first function is the Diagnostic
Trouble Code Check in which a malfunction in the signal circuits to the ECU is stored in code in the ECU
memory at the time of occurrence, to be output by the technician during troubleshooting. Another function
is the Input Signal Check which checks if the signals from various switches are sent to the ECU correctly.
By using these check functions, the problem areas can be narrowed down quickly and troubleshooting can
be performed effectively. Diagnostic functions are incorporated in the following systems in the LAND CRUIS-
ER.
SystemDiagnostic Trouble
Code CheckInput Signal Check
(Sensor Check)Other Diagnosis
Function
Engine
Automatic Transmission
ABS & Vehicle Stability Control (VSC) & Brake Assist (BA) System
Power Tilt and Power Telescopic Steering Column
Supplemental Restraint System
Theft Deterrent System
Cruise Control System
Engine Immobiliser System
Driver Door Control System
Navigation System
Air Conditioning System(with Test Mode)
(with Test Mode)
Cancel Signal
Check
In diagnostic trouble code check, it is very important to determine whether the problem indicated by the diag-
nostic trouble code is still occurring or occurred in the past but returned to normal at present. In addition,
it must be checked in the problem symptom check whether the malfunction indicated by the diagnostic
trouble code is directly related to the problem symptom or not. For this reason, the diagnostic trouble codes
should be checked before and after the symptom confirmation to determine the current conditions, as shown
in the table below. If this is not done, it may, depending on the case, result in unnecessary troubleshooting
for normally operating systems, thus making it more difficult to locate the problem, or in repairs not pertinent
to the problem. Therefore, always follow the procedure in correct order and perform the diagnostic trouble
code check.