Page 2113 of 4323
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±1911
2105 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1212 Front passenger door ECU commu-
nication stop
CIRCUIT DESCRIPTION
This DTC is indicated when communication fails between the passenger door ECU and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1212No communication from passenger door ECU for more than 10Passenger door ECU
Wi hB1212No communication from assenger door ECU for more than 10
seconds.Wire harness
Body ECU
DIDFC±01
Page 2114 of 4323
I28468
MPX2MPX1 D22
Driver Door ECU
Back Door ECU
IB1F18
Passenger
Door ECU
J/CII2
BF1 BD2 B11
J37 J38J/CJ34 J33 II2
II2MPX2
MPX1
SIG
BDR
GND F18 F18
F18 F18
F18 F18
F18 F18
F18 F18
F18 F18 G±B
B
B±R G±B G±B
BB B B
B±R
B±R
B±R B±Y
W±L
L±Y
L±Y
B
W±R
W±R
W±R
W±R
W±B A J12
J/C
Battery
IFII2
II2 Sub J/B No. 3
3D 3A11
611
13 8(*1) (*2) 23 12(*1) (*2) 2520
(*1)(*2) 21 19(*1) (*2) 20 10(*1) (*2) 811(*1) (*2)
Engine Room J/B
ECU±B
Short Pin
2D 2C18Instrument Panel J/B
1E 1J2 3II2 F10
Fusible Link Block
ALT
48 5Instrument Panel J/B
ECU±IG
AM1
PWR No. 2 1F 1C
1L 1C
1F 44
1
176
12 Sub J/B No. 3
3C 3A88I18
Ignition SW
IG1 AM14 8
8 2 1
14AG
2 7
(*1): w/ Driving Position Memory
(*2): w/o Driving Position Memory20
AA
3
B1
W±BCPUB W DI±1912
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2106 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
Page 2115 of 4323

± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±1913
2107 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check passenger door ECU.
CHECK:
Check if the passenger door window glass auto up function operates normally through the front passenger
door window switch.
HINT:
With this inspection, the passenger door ECU CPU can be diagnosed if it works normally or not.
OK:
Front passenger side power window auto up function operates normally.
NG Go to power source circuit (See page DI±1826).
OK
2 Check wire harness and connector (Passenger door ECU ± driver door ECU,
back door ECU).
PREPARATION:
Disconnect connector ºD22º of the driver door ECU, ºF18º of the passenger door ECU and ºB11º of the back
door ECU.
CHECK:
Measure the resistance according to the values in the table below.
OK:
Symbols (Tester connection)ConditionSpecified condition
MPX1 (D22±20) ± MPX2 (F18±8) (*1)AlwaysBelow 1 W
MPX1 (D22±20) ± MPX2 (F18±11) (*2)AlwaysBelow 1 W
MPX2 (B11±1) ± MPX1 (F18±20) (*1)AlwaysBelow 1 W
MPX2 (B11±1) ± MPX1 (F18±10) (*2)AlwaysBelow 1 W
MPX1 (D22±20) ± Body groundAlways10 kW or higher
MPX1 (B11±1) ± 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 passenger door ECU.
If the problem reoccurs even after replacement, replace the body ECU.
Page 2116 of 4323
DI±1914
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2108 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1214 Communication bus malfunction
(Short to B+)
DTC B1215 Communication bus malfunction
(Short to ground)
CIRCUIT DESCRIPTION
DTC B1214 or B1215 is detected when a short to +B or short to ground occurs on the multiplex communica-
tion bus (BEAN). Detecting this condition will disable the multiplex communication bus (BEAN) and output
the corresponding DTC.
DTC NO.DTC detecting conditionTrouble area
B1214Short to B+ in multiplex communication system communica-
tion circuit
Driver door ECU
Passenger door ECU
Back door ECU
A/C ECU (Integration control panel)
Combination meter
Memory seat ECU & switch
Wire harness
Body ECU
B1215Short to ground in multiplex communication system commu-
nication circuit
Driver door ECU
Passenger door ECU
Back door ECU
A/C ECU (Integration control panel)
Combination meter
Memory seat ECU & switch
Wire harness
Body ECU
DI94Y±07
Page 2117 of 4323
I28465
D22
Driver Door ECU
S19
Sliding Roof
Control ECU
Combination MeterI19
A/C ECU
(Integration Control and Panel)
Memory Seat ECU
& SwitchBody ECU
J/C
Back Door ECU
F18
Passenger
Door ECUInstrument Panel J/B
J/CIB1
1M 1GB7
B7
B5
M6 C5
II2J33 J34 BI2
BD2 BF1
B11 C5
C5
B11 J33 J34
BD2 BF1 II2 J33 J34 IB1MPX1
MPX2 MPX3 MPX1MPX2
MPX1
MPX1
MPX2 MPX1
MPX2
MPX1MPX±MPX+ W±L
G±B
G±O
LG±B L±Y
LG±RWW±L
G±O
W
LG±RLG±R
BLG±R
BBB B B
A G H A
G W
(*2)
10
8 11 (*2)
21
14762 4
G±B171 3 1324 31
32
30 8(*3)
(*1)
(*1) (*1)(*3) 3
9
1220 22
8
20
2
G±B
(*1): w/ Driving Position Memory
(*2): w/o Driving Position Memory
(*3): w/ Sliding Roof 8 (*1)(*1)
20
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±1915
2109 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
Page 2118 of 4323
DI±1916
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2110 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check apparatus.
CHECK:
Choose the apparatus to be inspected.
ApparatusGo to step
w/ Sliding roofA
w/o Sliding roofB
B Go to step 4.
A
2 Check the communication circuit inside the sliding roof control ECU.
PREPARATION:
Disconnect connector ºS19º of the sliding roof control ECU.
CHECK:
Check the DTC (See page DI±1904).
OK:
DTCs B1214 and/or B1215 are not indicated.
HINT:
Ignore any codes other than DTCs B1214 and B1215.
OK Replace sliding roof control ECU.
NG
3 Check for a short circuit between the sliding control ECU and body ECU.
PREPARATION:
(a) Reconnect connector ºS19º of the sliding roof control ECU (only vehicles w/ sliding roof).
(b) Disconnect connector ºB7º of the body ECU.
CHECK:
Check the DTC (See page DI±1904).
OK:
DTCs B1214 and/or B1215 are not indicated.
HINT:
Ignore any codes other than DTCs B1214 and B1215.
Page 2119 of 4323
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±1917
2111 Author: Date:
2005 SEQUOIA (RM1146U)
OK Repair or replace the wire harness between the
sliding roof control ECU and body ECU.
NG
4 Check the communication circuit inside the driver door ECU.
PREPARATION:
(a) Reconnect connector ºB7º of the body ECU (only vehicles w/ sliding roof).
(b) Disconnect connector ºD22º of the driver door ECU.
CHECK:
Check the DTC (See page DI±1904).
OK:
DTCs B1214 and/or B1215 are not indicated.
HINT:
Ignore any codes other than DTCs B1214 and B1215.
OK Replace the driver door ECU.
NG
5 Check the communication circuit inside the front passenger door ECU.
PREPARATION:
(a) Reconnect connector ºD22º of the driver door ECU.
(b) Disconnect connector ºF18º of the front passenger door ECU.
CHECK:
Check the DTC (See page DI±1904).
OK:
DTCs B1214 and/or B1215 are not indicated.
HINT:
Ignore any codes other than DTCs B1214 and B1215.
OK Replace the front passenger door ECU.
NG
Page 2120 of 4323
DI±1918
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2112 Author: Date:
2005 SEQUOIA (RM1146U)
6 Check for a short circuit between the driver door ECU and front passenger door
ECU.
PREPARATION:
Disconnect connector ºD22º of the driver door ECU.
CHECK:
Check the DTC (See page DI±1904).
OK:
DTCs B1214 and/or B1215 are not indicated.
HINT:
Ignore any codes other than DTCs B1214 and B1215.
OK Repair or replace the wire harness between the
driver door ECU and front passenger door ECU.
NG
7 Check communication circuit inside the back door ECU.
PREPARATION:
(a) Reconnect connector ºD22º of the driver door ECU.
(b) Reconnect connector ºF18º of the passenger door ECU.
(c) Disconnect connector ºB11º of the back door ECU.
CHECK:
Check the DTC (See page DI±1904).
OK:
DTCs B1214 and/or B1215 are not indicated.
HINT:
Ignore any codes other than DTCs B1214 and B1215.
OK Replace the back door ECU.
NG