Page 2145 of 4323
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±1943
2137 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1271 Combination meter ECU communica-
tion stop
CIRCUIT DESCRIPTION
This DTC is indicated when communication fails between the combination meter and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1271No communication from combination meter for more than 10
seconds.Combination meter
Wire harness
Body ECU
DIDFJ±01
Page 2146 of 4323
I28470
Back Door ECUCombination Meter
I19
A/C ECU
(Integration Control and Panel)
Instrument Panel J/B
I18
Ignition SW
Engine Room J/B
Instrument Panel J/B
J8
J/C F10
Fusible
Link Block
Battery
IEC6 B11
BF1BD2
J34J33C5
C5
C6 1J
1C1D
1H
1J 1C
2C 2D
2C
1D 1F C6 Short Pin
ECU±B
AM2IGN1
IG2 AM2MPX1
MPX±LG±B LG±RLG±R
LG±R
LG±B
W±R
B±O W±R
B±R
W±R W±R
W±R
W±R
W±B
BR B
BABH 231
32
23
24 67
13
3
29
11
5 637
1 8
1
9
612
5 4J/C DI±1944
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2138 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
Page 2147 of 4323

± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±1945
2139 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check combination meter.
CHECK:
Start the engine and check that the speed meter and tachometer operate normally.
HINT:
With this inspection, the combination meter CPU can be diagnosed if it works normally or not.
OK:
Speed meter and tachometer operate normally.
NG Go to combination system (See page DI±1610).
OK
2 Check wire harness and connector (Combination meter ± back door ECU, com-
bination meter ± integration control and panel).
PREPARATION:
Disconnect connector ºB11º of the back door ECU, connector ºC5º of the combination meter and connector
ºI19º of the integration control and panel.
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
I19±13 (MPX±) ± C5±32AlwaysBelow 1 W
B11±2 (MPX1) ± Body groundAlways10 kW or higher
I19±13 (MPX±) ± Body groundAlways10 kW or higher
NG Repair or replace wire harness.
OK
Replace the combination meter.
If the problem recurs even after replacement, replace the body ECU.
Page 2148 of 4323
DI±1946
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2140 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1272 Memory seat ECU communication stop (w/
Driving position memory)
CIRCUIT DESCRIPTION
This DTC is indicated when communication fails between the memory seat ECU & switch and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1272No communication from memory seat ECU & switch for more
than 10 seconds.Memory seat ECU & switch
Wire harness
Body ECU
DIDFK±01
Page 2149 of 4323
I28471
Combination MeterMemory Seat ECU
& SW
Sub J/B No. 3J/C
J24
J/C
Instrument Panel J/B
F10
Fusible Link BlockI18
Ignition SW
Engine Room J/B
Battery
BHJ24
J/C J/C
J/C C5 J33 BI2 M6J34
J31 J32
3A 3AJ33 J34
J33 J34BI2
BI2 BI2
M6
M6 M7
AM1 ECU±IG
1F
1L
1J 1E 1G1C
1 4
6
1 16
2
1C
2 4
PWR SEAT
1 2
M7 BI2 ECU±B
Short Pin
2D 2C18 ALT
IG1 AM1 12
BB
W±B
W±B W±B
B58W W±L
W±R W±RB±Y B±R
L±O
3 W±R
W±RW±R W±R B±R B±R B±R L±O
L±O L±O L±O
3 111 8151641
5
A 9 C
A GG A
WWW17 30
CL
I FMPX1
+B
IG
SYSB
GND 1 4
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±1947
2141 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM
Page 2150 of 4323
DI±1948
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2142 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Check power seat control system (w/ driving position memory).
CHECK:
Check the operation of the power seat.
OK:
The power seat control system operates normally.
NG Go to power source circuit (See page DI±1514).
OK
2 Check wire harness (Memory seat ECU & switch ± combination meter).
PREPARATION:
Disconnect connector ºM6º of the memory seat ECU and ºC5º of the combination meter.
CHECK:
Measure the resistance according to the values in the table below.
OK:
Tester connection (Symbols)ConditionSpecified condition
M6±1 (MPX1) ± C5±30AlwaysBelow 1 W
M6±1 (MPX1) ± Body groundAlways10 kW or higher
NG Repair or replace wire harness or connector.
OK
Replace memory seat ECU & switch.
If the problem recurs even after replacement, replace the body ECU.
Page 2151 of 4323
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
DI±1949
2143 Author: Date:
2005 SEQUOIA (RM1146U)
DTC B1273 Sliding roof ECU communication stop
(w/ Sliding roof)
CIRCUIT DESCRIPTION
This DTC is indicated when communication fails between the sliding roof ECU and body ECU.
DTC No.DTC Detecting ConditionTrouble Area
B1273No communication from sliding roof ECU for more than 10Sliding roof ECU
Wi hB1273No communication from sliding roof ECU for more than 10
seconds.Wire harness
Body ECU
DIDFL±01
Page 2152 of 4323
I28472
S19
Sliding Roof
Control ECUInstrument Panel J/BBody ECU
I18
Ignition SW
Instrument Panel J/B
F10
Fusible Link Block
Battery
IEJ8
J/C MPX1
E
B IGMPX3
IG1 AM11 2
AM1 ECU±IG
1F 1L 1MB7
1
6
12
1C4
SUN±ROOF
7 ALT
58W
AW±B B
W±B 1
5
1M
1M 10W±L
L±W B±RW±L
B±Y 2
7
51M 1G
L±WW±B G±O G±O
B±R 89
1220
1C DI±1950
± DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2144 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM