Page 2057 of 2572
B63408
Wire Harness Side
T4
Theft Warning ECU Assy
B51580
1
B51580
1
B64984
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
05-2029
2219 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
2 CHECK THEFT WARNING ECU ASSY (THEFT WARNING ECU - BODY GROUND)
(a) Disconnect the T4 ECU connector.
(b) Measure the voltage between the T4 ECU connector and
body ground.
Standard:
Tester ConnectionSpecified Condition
T4-3 (+B2) - Body ground10 to 14 V
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
3 CHECK SECURITY HORN ASSY
(a) Disconnect the T1 security horn connector.
(b) Check operation of the security horn.
Standard:
Measurement ConditionSpecified Condition
Battery positive (+) " Terminal 1
Battery negative (-) " Body groundSecurity horn blows
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
Page 2058 of 2572
B63408
B58961
1
B63408
B58961
1
B64978
Wire Harness Side
T1
Security Horn Assy T4
Theft Warning ECU Assy
05-2030
- DIAGNOSTICSTHEFT DETERRENT SYSTEM
2220 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
4 CHECK SECURITY HORN ASSY (THEFT WARNING ECU ASSY - SECURITY HORN
ASSY)
(a) Disconnect the T4 ECU connector.
(b) Disconnect the T1 security horn connector.
(c) Measure the resistance between the wire harness side
connectors.
Standard:
Tester ConnectionSpecified Condition
T4-1 (SH-) - T1-1Below 1 W
NG REPLACE SECURITY HORN ASSY
OK
Page 2059 of 2572
F46776
S27
Skid Control ECU
With Actuator Passenger Side J/B S15
Stop Light SW
Instrument Panel J/B
BatterySTP
27 IC4 4A11
4L
STOP
F7
FL Block
FL MAIN
EAJ4
J/CW-B
GND1 G-Y B 3
B
1 2
Y
1E1
1A1
B
B ALT32
A
EB W-BW-B W
1222 05-748
- DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
938 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
STOP LAMP SWITCH CIRCUIT
CIRCUIT DESCRIPTION
When the stop lamp switch is ON (brake pedal depressed), the skid control ECU suspends the tire pressure
warning system.
WIRING DIAGRAM
05IOZ-02
Page 2060 of 2572
F45562
Wire Harness Side:
S27STP
GND1
- DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
05-749
939 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
INSPECTION PROCEDURE
1 CHECK STOP LAMP SWITCH OPERATION
(a) Check that the stop lamp comes on when the brake pedal is depressed, and goes off when the brake
pedal is released.
OK:
Stop lamp functions normally.
NG Go to step 3
OK
2 CHECK HARNESS AND CONNECTOR(BRAKE ACTUATOR ASSY - STOP LAMP
SWITCH ASSY) (SEE PAGE 01-36)
(a) Disconnect the brake actuator assy connector.
(b) Measure the voltage according to the value(s) in the table
below.
Standard:
Switch conditionTester connectionSpecified condition
Brake pedal depressedS27-27 (STP) -
S27-32 (GND1)10 to 14 V
Brake pedal releasedS27-27 (STP) -
S27-32 (GND1)Below 1.5 V
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
(SEE PAGE 05-740)
3 CHECK REAR COMBINATION LAMP ASSY LH
NG REPLACE REAR COMBINATION LAMP ASSY
LH
OK
Page 2061 of 2572

F45894
Stop Lamp Switch Assy:
1 2
Pushed In Free
F45562
Wire Harness Side:
S27STP
GND1
05-750
- DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
940 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
4 INSPECT STOP LAMP SWITCH ASSY
(a) Disconnect the stop lamp switch assy S15 connector.
(b) Measure the resistance according to the value(s) in the
table below.
Standard:
Switch conditionTester connectionSpecified condition
Switch pin free1 - 2Below 1 W
Switch pin pushed in1 - 210 kW or higher
NG REPLACE STOP LAMP SWITCH ASSY
OK
5 CHECK HARNESS AND CONNECTOR(BRAKE ACTUATOR ASSY - STOP LAMP
SWITCH ASSY) (SEE PAGE 01-36)
(a) Connect the stop lamp switch assy S15 connector.
(b) Disconnect the brake actuator assy connector.
(c) Measure the voltage according to the value(s) in the table
below.
Standard:
Switch conditionTester connectionSpecified condition
Brake pedal depressedS27-27 (STP) -
S27-32 (GND1)10 to 14 V
Brake pedal releasedS27-27 (STP) -
S27-32 (GND1)Below 1.5 V
NG REPAIR OR REPLACE HARNESS OR
CONNECTOR
OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
(SEE PAGE 05-740)
Page 2062 of 2572
- DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
05-751
941 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
ABS SYSTEM MALFUNCTION
CIRCUIT DESCRIPTION
The skid control ECU outputs DTCs when a speed sensor malfunction occurs or there is an open in the stop
lamp switch assy circuit of the ABS system. If ABS system has a malfunction, tire pressure warning system
will not function.
INSPECTION PROCEDURE
1 CHECK DIAGNOSTIC TROUBLE CODE OUTPUT
(a) Check that the normal code is output by ABS system (see page 05-765).
OK:
DTC is not output.
NG REPAIR CIRCUIT INDICATED BY OUTPUT
CODE
OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
(SEE PAGE 05-740)
05EZ4-02
Page 2063 of 2572
F46777
S27
Skid Control ECU
With Actuator
Passenger Side J/B
INIT
41
GND1 J4
J/C
EB P22
Tire Pressure Warning
Reset Switch
IC42
ICB-Y
SB W-B
4J 4L6
7
W-B
32 W-B W-B
W-B
EAA 21
05-752
- DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
942 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
TIRE PRESSURE WARNING RESET SWITCH CIRCUIT
CIRCUIT DESCRIPTION
Receiving the signal from the tire pressure warning reset switch, the skid control ECU indicates initialization
of the tire pressure warning system.
WIRING DIAGRAM
INSPECTION PROCEDURE
1 CHECK TIRE PRESSURE WARNING RESET SWITCH (SEE PAGE 05-737)
OK:
Tire pressure warning reset switch functions normally.
NG Go to step 2
OK
CORRECT TIRE PRESSURE TO THE SPECIFIED PRESSURE, THEN INITIALIZE THE SYSTEM
05IP0-02
Page 2064 of 2572

F44158
ON
OFF
1
2
Tire Pressure Warning Reset Switch:
F45562
Wire Harness Side:
S27
INIT GND1
- DIAGNOSTICSTIRE PRESSURE WARNING SYSTEM
05-753
943 Author: Date:
2005 HIGHLANDER REPAIR MANUAL (RM1144U)
2 INSPECT TIRE PRESSURE WARNING RESET SWITCH
(a) Disconnect the tire pressure warning reset switch P22
connector.
(b) Measure the resistance according to the value(s) in the
table below.
Standard:
Switch conditionSpecified condition
ONBelow 1 W
OFF10 kW or higher
NG REPLACE TIRE PRESSURE WARNING RESET
SWITCH
OK
3 CHECK HARNESS AND CONNECTOR(TIRE PRESSURE WARNING RESET
SWITCH - BRAKE ACTUATOR ASSY) (SEE PAGE 01-36)
(a) Reconnect the tire pressure warning reset switch P22
connector.
(b) Disconnect the brake actuator assy connector.
(c) Measure the resistance according to the value(s) in the
table below.
Standard:
Switch conditionTester connectionSpecified condition
ONS27-41 (INIT) -
S27-32 (GND1)Below 1 W
OFFS27-41 (INIT) -
S27-32 (GND1)10 kW or higher
NG REPAIR OR REPLACE HARNESS AND
CONNECTOR
OK
PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
(SEE PAGE 05-740)