Page 1249 of 2572
B51594
A11
A10
C11 Combination Meter Assy (Meter ECU)
Power Window Regulator
Master Switch Assy (Door ECU) Air Conditioner Amplifier Assy (A/C ECU)
P5 05-2072
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2262 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
INSPECTION PROCEDURE
1 CHECK CONTINUITY OF COMMUNICATION LINE
(a) Inspect the wire harness between the combination meter assy (meter ECU), air conditioner amplifier
assy (A/C ECU) and power window regulator master switch assy (door ECU).
Page 1250 of 2572

B51596
A10
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
05-2073
2263 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
(1) Disconnect the connectors of the air conditioner amplifier, master switch and meter assy.
(2) Inspect the continuity between terminal A10-9 (MPX-) of the air conditioner amplifier vehicle's
side connector and terminal C11-21 (MPX-) of the meter assy vehicle's side connector.
Standard: Continuity
(3) Inspect the continuity between terminal A11-2 (MPX+) of the air conditioner amplifier vehicle's
side connector and terminal P5-7 (MPX1) of the master switch.
Standard: Continuity
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
2 CHECK AIRCONDITIONER AMPLIFIER ASSY
(a) Inspect the air conditioner amplifier assy (A/C ECU) (power source input).
(1) Disconnect the air conditioner amplifier connector A10.
(2) Inspect the voltage between terminal A10-12 (+B) of the vehicle's side connector and the body
ground.
Standard: 10 - 14 V
NG REPAIR OR REPLACE FUSE OR WIRE
HARNESS AND CONNECTOR
OK
Page 1251 of 2572
B51837
A10
05-2074
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2264 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
3 CHECK AIRCONDITIONER AMPLIFIER ASSY
(a) Inspect the air conditioner amplifier assy (A/C ECU) (body ground).
(1) Disconnect the air conditioner amplifier connector A10.
(2) Inspect the continuity between terminal A10-11 (GND) of the vehicle's side connector and the
body ground.
Standard: Continuity
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
REPLACE AIRCONDITIONER AMPLIFIER ASSY
Page 1252 of 2572
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
05-2075
2265 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC B1269/69 THEFT DETERRENT ECU COMMUNICATION
STOP
CIRCUIT DESCRIPTION
B1269/69 will be output when the communication between the theft warning ECU assy (theft deterrent ECU)
and multiplex network body ECU stops for more than 10 seconds.
DTC No.DTC Detecting ConditionTrouble Area
B1269/69No communication from theft deterrent ECU for more than 10 secondsTheft warning ECU assy (theft deterrent ECU)
Wire harness
05241-06
Page 1253 of 2572
H45692
T4
Theft Warning ECU Assy
(Theft Deterrent ECU)
A10
Air Conditioner
Amplifier Assy
(A/C ECU) F7
FL Block AssyEngine Room J/B
Combination
Meter 1 41D9
MPX1
21 1G10
BR
2A
2I SECURITYW-L3 IC3
BatteryJ17
J/C
1ECU-B
MPX- 3H V IF1
35
Y31
Center
J/B
3E 3J L
+B2
+B1
2 O
IL1112
W 4
L
P P
IC3 5
52A
D.C.C.
W
FL Main WMPX-C11
G53D
3F 11213
9W-B
IB 29
W-B EEE Instrument
Panel J/B 05-2076
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2266 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
WIRING DIAGRAM
Page 1254 of 2572
H45691
Theft Warning ECU Assy
(Theft Deterrent ECU)
Air Conditioner
Amplifier Assy
(A/C ECU)
Combination MeterA10
C11 T4
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
05-2077
2267 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
INSPECTION PROCEDURE
1 CHECK CONTINUITY OF COMMUNICATION LINE
(a) Check the wire harness between the combination meter, theft warning ECU assy (theft deterrent ECU)
and airconditioner amplifier assy (A/C ECU).
Page 1255 of 2572

B50657
4T4
05-2078
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2268 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
(1) Disconnect the connectors of the theft warning ECU, master switch and air conditioner amplifier.
(2) Check the continuity between terminal T4-31 (MPX1) of the theft warning ECU vehicle's side
connector and terminal C11-21 (MPX-) of the master switch vehicle's side connector.
(3) Check the continuity between terminal T4-31 (MPX1) of the theft warning ECU vehicle's side
connector and terminal A10-9 (MPX-) of the air conditioner amplifier vehicle's side connector.
Standard: Continuity
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
2 CHECK THEFT WARNING ECU ASSY
(a) Inspect the theft warning ECU assy (theft deterrent ECU) (power source input).
(1) Disconnect the theft warning ECU connector.
(2) Check the voltage between terminal T4-2 (+B1) and T4-8 (+B2) of the theft warning ECU and
the body ground.
Standard: 10 - 14 V
NG REPAIR OR REPLACE FUSE OR WIRE
HARNESS AND CONNECTOR
OK
Page 1256 of 2572
B50657
T4
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
05-2079
2269 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
3 CHECK THEFT WARNING ECU ASSY
(a) Inspect the theft warning ECU assy (theft deterrent ECU) (body ground).
(1) Disconnect the theft warning ECU connector.
(2) Check the continuity between terminal T4-29 (E) of the theft warning ECU vehicle's side connec-
tor and the body ground.
Standard: Continuity
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
REPLACE THEFT WARNING ECU ASSY