2001 TOYOTA SEQUOIA ECU

± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±1951
2145 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check sliding roof ECU.
CHECK:
Check that the operation of the sliding roof function is normal.
HINT:
The operating condition of the sliding roof ECU CPU can be diagnosed with this check.
OK:
The sliding roof operates normally.
NG Go to power source circuit (See page DI±1668).
OK
2 Check wire harness and connector (Sliding roof control ECU ± body ECU).
PREPARATION:
Disconnect connector ºB7º of the body ECU and connector ºS19º of the sliding roof ECU.
CHECK:
Measure the resistance according to the values in the table below.
OK:
Tester connection (Symbols)ConditionSpecified condition
S19±2 (MPX1) ± B7±20 (MPX3)AlwaysBelow 1 W
S19±2 (MPX1) ± Body groundAlways10 kW or higher
NG Repair or replace wire harness.
OK
Replace the sliding roof ECU.
If the problem recurs even after replacement, replace the body ECU.

DI±1952
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2146 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1287 Back door ECU communication stop
CIRCUIT DESCRIPTION
This DTC is indicated when communication fails between the back door ECU and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1287No communication from back door ECU for more than 10 se-
conds.
Back door ECU

Wire harness

Body ECU
DIDFM±01

I28473
Combination Meter
F18
Front Passenger
Door ECUBack Door ECU
Sub J/B No. 3I18
Ignition SW Instrument Panel J/B
F10
Fusible Link Block
Engine Room J/BInstrument Panel J/B
Sub J/B No. 3
Battery
BJJ19
J/CJ22
J/C J37
J/CJ/C
J/C J33 J34
J33 J34 C5B11 BF1 BD2
II2B11
B11
B11 BF1 BD2
BD2 BF1 IN1
AM1 ECU±IG
1F
1L
1G1C
14
6
12
1C
154
12PWR No. 5 ALT
58
43C 3A88AAGAB H
IG1
AM1
1 26 7 312
1
6
4 2
5 11 1114 8
BB B B B
20 (*1)LG±R
B±RLG±R LG±R LG±R
B±RB±R B±R B±R
B±R B±Y
W±L W
B B
L±W L±W L±W L±W
W±R
W±R W±R
W±R W±R W±R
W±B W±B W±B W±B
A212
BB3 5
B11
B11 10 12 11 2
3A 3C
BD2 BF1
BF1 BD1IN1BF1 BD1 IC4
2 3 8 1
1J
1E 2C 2DECU±B
Short Pin
23
10MPX1
SIG
BDR
GND MPX2
BECU MPX1
*1: w/ Driving Position Memory
*2: w/o Driving Position Memory 10 (*2)
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±1953
2147 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

DI±1954
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2148 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check back door ECU.
CHECK:
Check that the operation of the rear wiper motor function is normal.
HINT:
With this inspection, the back door ECU CPU can be diagnosed if it works normally or not.
OK:
Rear wiper motor operates normally.
NG Replace the back door ECU.
OK
2 Check wire harness and connector (Back door ECU ± combination meter, back
door ECU ± passenger door ECU).
PREPARATION:
Disconnect connector ºF18º of the passenger door ECU, connector ºB11º of the back door ECU and connec-
tor ºC5º of the combination meter ECU.
CHECK:
Measure the resistance according to the values in the table below.
OK:
Tester connection (Symbols)ConditionSpecified condition
B11±2 (MPX1) ± C5±31AlwaysBelow 1 W
B11±1 (MPX2) ± F18±10 (*1)AlwaysBelow 1 W
B11±1 (MPX2) ± F18±20 (*2)AlwaysBelow 1 W
B11±1 (MPX2) ± Body groundAlways10 kW or higher
B11±2 (MPX1) ± Body groundAlways10 kW or higher
*1: w/ Driving Position Memory
*2: w/o Driving Position Memory
NG Repair or replace wire harness.
OK
Replace the back door ECU.
If the problem recurs even after replacement, replace the body ECU.

DID9K±01
I27726
Radio Receiver Assy
Rear Door Speaker Tweeter
Rear Door Speaker Front Door Speaker (*1)
Front Door Speaker and
Woofer (*2)Steering Pad
Switch
Instrument Panel J/B

RAD NO. 2 Fuse

ECU±B Fuse

AM1 FuseEngine Room J/B

RAD NO. 1 Fuse

RAD NO. 3 Fuse
Ignition Switch
Disc Player
Controller
(*3)
Stereo
Component
AmplifierMulti±display
Controller (*3)
VTR
Terminal
(*3)Headphone
Terminal
(*3, *4)
Television Display Assy (*3)
Rear Seat Audio
Controller Assy (*4)
Radio Sub
Antenna*1: Built±in Type Amplifier
*2: Separate Type Amplifier
*3: w/ RSE System
*4: w/ RSA System Radio Main Antenna
DI±1956
± DIAGNOSTICSAUDIO SYSTEM
2150 Author: Date:
2005 SEQUOIA (RM1146U)
LOCATION

DID9R±01
I28312
R4R19R20
± DIAGNOSTICSAUDIO SYSTEM
DI±1969
2163 Author: Date:
2005 SEQUOIA (RM1146U)
TERMINALS OF ECU
1. RADIO RECEIVER ASSY (SEPARATE TYPE AMPLIFIER)
Symbols (Terminal No.)Wiring ColorTerminal DescriptionConditionSpecification
BU+B (R4±1) ± GND (R4±20)L±Y ± BRBatteryAlways10 to 14 V
ILL+ (R4±2) ± GND (R4±20)G ± BRIllumination (dimmer)
signalLight control switch OFF " TAIL or
HEADBelow 1 V "
10 to 14 V
TX+ (R4±5) ± GND (R4±20)V ± BRAVC±LAN
communication signalIgnition switch ON2 to 3 V
MUTE (R4±7) ± GND (R4±20)R±W ± BRMUTE signalAudio system is playing "changing
modeAbove 3.5 V "
Below 1 V
R+ (R4±8) ± GND (R4±20)W ± BRSound signal
(Right output)Audio system is playing
A waveform synchro-
nized with sounds is
output
L+ (R4±9) ± GND (R4±20)B ± BRSound signal
(Left output)Audio system is playing
A waveform synchro-
nized with sounds is
output
GND (R4±10) ± Body groundShielded ±
Body groundShield groundAlwaysBelow 1 V
ACC+B (R4±11) ±
GND (R4±20)GR ± BRAccessory (ON)Turn ignition switch to OFF "ACC10 to 14 V
ILL± (R4±12) ± GND (R4±20)W±G ± BRIllumination (rheostat)
signalLight control switch TAILBelow 1 V "
10 to 14 V
ANT+B (R4±13) ±
GND (R4±20)B±R ± BRPower source of antennaRadio switch ON and AM or FM10 to 14 V
TX± (R4±15) ± GND (R4±20)P ± BRAVC±LAN
communication signalIgnition switch ON2 to 3 V
R± (R4±18) ± GND (R4±20)G ± BRSound signal
(Right output)Audio system is playing
A waveform synchro-
nized with sounds is
output
L± (R4±19) ± GND (R4±20)R ± BRSound signal
(Left output)Audio system is playing
A waveform synchro-
nized with sounds is
output
GND (R4±20) ± Body groundBR ±
Body groundGroundAlwaysBelow 1 V
GND (R19±6) ± GND (R4±20)BR±W ± BRSteering pad switch
groundAlwaysBelow 1 V
SW1 (R19±7) ± GND (R4±20)LG±R ± BRSteering pad switch signal
Steering pad switch not operating.
"SEEK+ switch push
"SEEK± switch push
"VOL+ switch push
"VOL± switch push4 V or more
"Approx. 0.5 V
"Approx. 0.9 V
"Approx. 2.0 V
"Approx. 3.4 V
SW2 (R19±8) ± GND (R4±20)GR±R ± BRSteering pad switch signalSteering pad switch not operating
"MODE switch push4 V or more "
Below 2.5 V

DID9S±01
I24383
º1chº Switch
ºSEEK TRACKº
DOWN SwitchºSEEK TRACKº
UP SwitchºDISCº Switch º2chº Switchº3chº Switch
º4chº Switchº5chº Switch
º6chº Switch
DI±1974
± DIAGNOSTICSAUDIO SYSTEM
2168 Author: Date:
2005 SEQUOIA (RM1146U)
DTC CHECK / CLEAR
1. DIAGNOSTIC CHECK
(a) Starting Diagnostic Mode (All elements come on during the SW check mode).
(1) Turn off the audio system and turn the ignition switch to the ACC position. While pressing the
preset switches º1º and º6º at the same time, press the ºDISCº 3 times.
(2) Reference:
When the system enters the Diagnosis Mode, a beep sound is emitted 3 times and all the
elements come on during the SW check mode.
It takes about 40 seconds to complete the check.
Turn all the elements in the LCD on.
When pressing the switch, confirm beep sound is emitted.
(b) Service Check Screen.
(1) Press the ºSEEK TRACKº switch to enter the ºService Check Screenº.
(2) In the service check mode, the system check and the diagnostic memory check are performed,
and the check results are displayed in ascending order of the component codes (physical ad-
dress.)
TermsMeaning
Component code
(Physical address)Three±digit code (In hexadecimal) given to each device comprising AVC±LAN.
Corresponding to its function, individual symbol is provided.
Logical addressTwo±digit code (In hexadecimal) given to each function and device unit in each
device comprising AVC±LAN.
Code No. (physical address) List
Code No.
(physical address)Equipment name
190Radio receiver assy (Audio head unit)
440Stereo component amplifier assy
1F6Multi±display controller (RSE ECU)
1F4Rear seat audio controller
(c) Finishing Diagnostic Mode.
Press the ºDISCº for 2 seconds or more, or turn the ignition switch off.

DI±1986
± DIAGNOSTICSAUDIO SYSTEM
2180 Author: Date:
2005 SEQUOIA (RM1146U)
3. Multi±display controller sub±assy (Physical address: 1F6) [RSE ECU, MAIN]
(a) Logical address: 01 (Communication control)
DTCNameDiagnosisVerificationSee page
21ROM ErrorAbnormal condition of ROM is detected.Replace multi±display controller
sub±assy.±
22ROM ErrorAbnormal condition of RAM is detected.Replace multi±display controller
sub±assy.±
D1
*1
Registered component discon-
nected
AVC±LAN transmitting abnor-
malitiesComponent shown by sub±code is or was discon-
nected from system with ignition switch in ACC or
ON.
Communication with component shown by sub±
code is not ensured when engine is started.
1. Power source circuit (Multi±dis-
play controller sub±assy).
2. AVC±LAN (Radio receiver assy
± Multi±display controller sub±
assy).
3. Replace Multi±display controller
sub±assy.DI±2110
DI±2139
±
D7
*2No response to connection
checkComponent shown by sub±code is or was discon-
nected from system after engine started.
1. Power source circuit (Multi±dis-
play controller sub±assy).
2. AVC±LAN (Radio receiver assy
± Multi±display controller sub±
assy).
3. Replace Multi±display controller
sub±assy.DI±2110
DI±2139
±
D7
*2AVC±LAN Communication
Check Error
Component in which this code is recorded is or
was disconnected from system after engine start.
Or, when recording this code, multi±display con-
troller was disconnected.
1. Power source circuit (Radio re-
ceiver assy).
2. Power source circuit (Multi±dis-
play controller sub±assy).
3. AVC±LAN (Radio receiver assy
± Multi±display controller sub±
assy).
4. Replace Multi±display controller
sub±assy.DI±1990
DI±2110
DI±2139
±
D6
*1Absence of Master
Component in which this code is recorded has
been disconnected from system with ignition in
ACC or ON. Or, when this code was recorded,
multi±display controller was disconnected.
1. Power source circuit (Radio re-
ceiver assy).
2. AVC±LAN (Radio receiver assy
± Multi±display controller sub±
assy).
3. Replace Multi±display controller
sub±assy.DI±1990
DI±2139
±
D7
*2Connection Check Error
Component in which this code is recorded has
been disconnected from system after engine start.
Or, when this code was recorded, multi±display
controller was disconnected.
1. Power source circuit (Radio re-
ceiver assy).
2. AVC±LAN (Radio receiver assy
± Multi±display controller sub±
assy).
3. Replace Multi±display controller
sub±assy.DI±1990
DI±2139
±
DC
*3Transmission Error
Transmission to component shown by sub±code
has been failed.
(This code does not necessarily mean actual fail-
ure.)If same sub±code is recorded in
other component(s), check harness
for power supply and communica-
tion system of all components
shown by code.
±
DD
*4Master Reset (Momentary Inter-
ruption)Component that is to be master has been discon-
nected after engine start.
1. Power source circuit (Radio re-
ceiver assy).
2. AVC±LAN (Radio receiver assy
± Multi±display controller sub±
assy).
3. Replace Multi±display controller
sub±assy.DI±1990
DI±2139
±