Page 1257 of 2572
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
05-2085
2275 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC B1273/73 SLIDING ROOF ECU COMMUNICATION
STOP
CIRCUIT DESCRIPTION
B1273/73 will be output when the communication between the sliding roof drive gear sub-assy (sliding roof
ECU) and the MPX body ECU stops for more than 10 seconds.
DTC No.DTC Detecting ConditionTrouble Area
B1273/73No communication from sliding roof ECU for more than 10 secondsSliding roof drive gear sub-assy (sliding roof ECU)
Wire harness
05243-03
Page 1258 of 2572
H45687
Combination Meter
(Meter ECU)S20
Sliding Roof Drive Gear Sub-assy
(Sliding Roof ECU)
E6
ECMIC IE12
8
2 1A
S/ROOF
SB W
1H
BB
IE1
8
IL2 1L
Y10
4D
4N
4L
W-BW-B
IA 5
1 Instrument
Panel J/B
1F7
FL Block Assy
FL MainEW-B
W-B
IE1 6
GR
GRGR
C12MPX2 929
MPX+1Passenger Side J/ B
67
4M
W-B
W-B Instrument
Panel J/B
Assy41E
1D 14
Battery7
1
MPX1 05-2086
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2276 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
WIRING DIAGRAM
Page 1259 of 2572
H45690
E6
C12 Combination Meter Assy (Meter ECU)
Sliding Roof Drive Gear Sub-Assy
(Sliding Roof ECU)ECM
S20
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
05-2087
2277 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
INSPECTION PROCEDURE
1 CHECK CONTINUITY OF COMMUNICATION LINE
(a) Inspect the wire harness between the ECM, sliding roof drive gear sub-assy (sliding roof ECU) and
combination meter assy (meter ECU).
Page 1260 of 2572

B51840
S20
05-2088
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
2278 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
(1) Disconnect the connectors of the sliding roof ECU, ECM and meter assy.
(2) Inspect the continuity between terminal S20-10 (MPX1) of the sliding roof ECU vehicle's side
connector and terminal E6-29 (MPX2) of the ECM vehicle's side connector.
Standard:
Symbols (Terminal No.)Specified Condition
MPX1 (S20-10) @ MPX2 (E6-29)
(equipped with 1MZ-FE)Continuity
MPX1 (S20-10) @ MPX2 (E6-29)
(equipped with 2AZ-FE)Continuity
(3) Inspect the continuity between terminal S20-10 (MPX1) of the sliding roof ECU vehicle's side
connector and terminal C12-9 (MPX+) of the meter assy vehicle's side connector.
Standard: Continuity
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
2 CHECK SLIDING ROOF DRIVE GEAR SUB-ASSY
(a) Inspect the sliding roof drive gear sub-assy (sliding roof
ECU).
(1) Disconnect the sliding roof ECU connector.
(2) Inspect the voltage of each terminal of the vehicle's
side connector.
Standard:
Symbols (Terminal No.)ConditionSpecified Condition
B (S20-1) @ Body groundConstant10 - 14 V
NG REPAIR OR REPLACE FUSE OR WIRE
HARNESS AND CONNECTOR
OK
Page 1261 of 2572
B51841
S20
- DIAGNOSTICSMULTIPLEX COMMUNICATION SYSTEM
05-2089
2279 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
3 CHECK SLIDING ROOF DRIVE GEAR SUB-ASSY
(a) Inspect the sliding roof drive gear sub-assy (sliding roof
ECU).
(1) Disconnect the sliding roof ECU connector.
(2) Inspect the voltage of each terminal of the vehicle's
side connector.
Standard:
Symbols (Terminal No.)ConditionSpecified Condition
E (S20-7) @ Body groundConstantContinuity
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
REPLACE SLIDING ROOF DRIVE GEAR SUB-ASSY
Page 1262 of 2572
I18376
A/C Amplifier assy
SG-3
TR A11A113
4 Y
W R6
Cooler (Room Temperature
Sensor)Thermistor1
2 05-1 130
- DIAGNOSTICSAIR CONDITIONING SYSTEM
1320 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
DTC B1411/11 ROOM TEMPERATURE SENSOR CIRCUIT
CIRCUIT DESCRIPTION
This sensor detects the temperature inside the cabin and sends the appropriate signals to the A/C amplifier
assy.
DTC No.Detection itemTrouble Area
B1411/11Open or short in room temperature sensor circuit
Cooler (room temperature sensor) thermistor
Harness or connector between cooler (room temperature
sensor) thermistor and A/C amplifier assy
A/C amplifier assy
WIRING DIAGRAM
05ITS-01
Page 1263 of 2572

I30331SG-3 (-) TR (+)
A/C Amplifier Connector
Wire Harness View:
A11
- DIAGNOSTICSAIR CONDITIONING SYSTEM
05-1 131
1321 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
INSPECTION PROCEDURE
HINT:
In case of using the hand-held tester, start the inspection step 1 and in case of not using the hand-held
tester, start from step 2.
1 READ VALUE OF HAND-HELD TESTER
(a) Connect the hand-held tester to the DLC3.
(b) Turn the ignition switch ON and push the hand-held tester main switch ON.
(c) Select the items below in the DATA LIST,and read the displays on the hand-held tester.
A C:
ItemMeasurement Item/Display
(Range)Normal ConditionDiagnostic Note
ROOM TEMP
Room temperature sensor
/min.: -6.5C (20.3F)
max.: 57.25C (135.05F)
Actual room temperature-
Result:
NGA
OK (Checking from the DTC)B
OK (Checking from the PROBLEM SYMPTOM TABLE)C
B REPLACE AIRCONDITIONER AMPLIFIER ASSY
C PROCEED TO NEXT CIRCUIT INSPECTION
SHOWN IN PROBLEM SYMPTOMS TABLE (SEE
PAGE 05-1 129)
A
2 INSPECT AIRCONDITIONER AMPLIFIER ASSY(TR, SG-3)
(a) Remove A/C amplifier assy with connectors still con-
nected.
(b) Turn the ignition switch to the ON position.
(c) Measure the voltage according to the value(s) in the table
below.
Standard:
Tester connectionConditionSpecified condition
A11-3 (SG-3) -
A11-4 (TR)at 25C (77F)1.8 to 2.2 V
A11-3 (SG-3) -
A11-4 (TR)at 40C (104F)1.2 to 1.6 V
HINT:
As the temperature increases, the voltage decreases.
OK REPLACE AIRCONDITIONER AMPLIFIER ASSY
NG
Page 1264 of 2572

I30111
Cooler Thermistor Connector
Front View:
R6
I38777I40673
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.0 0.5
020 40 Resistance
(kW)
Temperature 6810460 (
5C)
140 (
5F)
32Maximum permissible value line
Minimum permissible value line
05-1 132
- DIAGNOSTICSAIR CONDITIONING SYSTEM
1322 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
3 INSPECT COOLER (ROOM TEMP. SENSOR) THERMISTOR
(a) Remove cooler (room temperature sensor) thermistor.
(b) Measure the resistance according to the value(s) in the
table below.
Standard:
Tester connectionConditionSpecified condition
R6-1 - R6-2105C (505F)3.00 to 3.73 kW
R6-1 - R6-2155C (595F)2.45 to 2.88 kW
R6-1 - R6-2205F (685F)1.95 to 2.30 kW
R6-1 - R6-2255C (775F)1.60 to 1.80 kW
R6-1 - R6-2305C (865F)1.28 to 1.47 kW
R6-1 - R6-2355C (955F)1.00 to 1.22 kW
R6-1 - R6-2405C (1045F)0.80 to 1.00 kW
R6-1 - R6-2455C (1135F)0.65 to 0.85 kW
R6-1 - R6-2505C (1225F)0.50 to 0.70 kW
R6-1 - R6-2555C (1315F)0.44 to 0.60 kW
R6-1 - R6-2605C (1405F)0.36 to 0.50 kW
NOTICE:
Even slightly touching the sensor may change the re-
sistance value. Be sure to hold the connector of the
sensor.
When measuring the sensor temperature must be the
same as the ambient temperature.
HINT:
As the temperature increases, the resistance decreases (see
the chart below).