2001 TOYOTA SEQUOIA Page 18

F16805
S25
Wire Harness View:
BAT
B
GND
DI±762
± DIAGNOSTICSAIR SUSPENSION SYSTEM
956 Author: Date:
2005 SEQUOIA (RM1146U)
1 Inspect suspension control ECU (ECU power source).
PREPARATION:
Disconnect the ECU connector.
CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:
Tester connection
(Symbol)Conditionspecified condition
S25±24 (B) ±
S25±22 (GND)Always10 to 14 V
S25±25 (BAT) ±
S25±22 (GND)Always10 to 14 V
NG Check power source circuit
(See page DI±761).
OK
Replace suspension control ECU
(See page IN±35).

DI±764
± DIAGNOSTICSAIR SUSPENSION SYSTEM
958 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect battery voltage.
CHECK:
Check the battery voltage.
OK:
Voltage: 11 to 14 V
NG Replace battery.
OK
HINT:
Start the inspection from step 2 when using the hand±held tester, and start from step 3 when not using the
hand±held tester.
2 Read value of the hand±held tester.
PREPARATION:
(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 item ºPOWER VOLTAGEº in the DATA LIST, and read its value displayed on the hand±held
tester.
AIR SUSPENSION:
ItemMeasurement Item / Range (Dis-
play)Normal ConditionDiagnostic Note
POWER VOLTAGE+B power source voltage / min.: 0
V, max.: 25.5 VActual battery power supply volt-
age: 10 to 14 V±
CHECK:
Check the battery positive voltage.
OK:
Actual battery power supply voltage: 10 to 14 V
RESULT:
NGA
OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE)B
OK (When troubleshooting according to the DTC chart)C
B Proceed to next circuit inspection shown in
problem symptoms table (See page DI±716).
C Check for intermittent problems.
HINT:
Check the connector and terminal (See page IN±24).

F16805
Wire Harness View:
GND S25
DI±766
± DIAGNOSTICSAIR SUSPENSION SYSTEM
960 Author: Date:
2005 SEQUOIA (RM1146U)
5 Check harness and connector (Suspension control ECU ± Body ground).
CHECK:
Check continuity between terminal S25±22 (GND) and body
ground.
OK:
Continuity
NG Repair or replace harness or connector.
OK
Replace suspension control ECU
(See page IN±35).

F16805
Wire Harness View:
S25
STP
DI±768
± DIAGNOSTICSAIR SUSPENSION SYSTEM
962 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect stop light.
CHECK:
Check that the stop light comes on when the brake pedal is depressed and goes off when the brake pedal
is released.
OK:
Stop light operates normally.
NG Go to step 3.
OK
2 Inspect suspension control ECU.
PREPARATION:
Disconnect the ECU connector.
CHECK:
Measure the voltage between terminal S25±27 (STP) of the
suspension control ECU and body ground when the stop light
switch is ON and OFF.
OK:
Switch conditionSpecified condition
Brake pedal depressed (ON)10 to 14 V
Brake pedal released (OFF)Below 1 V
NG Repair or replace harness connector.
OK
Replace suspension control ECU
(See page IN±35).

I21525
Free Pushed in
F16805
Wire Harness View:
S25
STP
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±769
963 Author: Date:
2005 SEQUOIA (RM1146U)
3 Inspect stop light switch assy.
PREPARATION:
Disconnect the stop light switch assy connector.
CHECK:
Check resistance between terminals 1 and 4 of the stop light
switch assy.
OK:
Switch conditionTester connectionSpecified condition
Switch pin free1 ± 4Below 1 W
Switch pin pushed in1 ± 410 kW or higher
NG Replace stop light switch assy.
OK
4 Inspect suspension control ECU.
PREPARATION:
Disconnect the ECU connector.
CHECK:
Measure the voltage between terminal S25±27 (STP) of the
suspension control ECU and body ground when the stop lamp
switch is ON and OFF.
OK:
Switch conditionSpecified condition
Brake pedal depressed (ON)10 to 14 V
Brake pedal released (OFF)Below 1 V
NG Repair or replace harness connector.
OK
Replace suspension control ECU
(See page IN±35).

F19447
Body ECUSuspension Control
ECU
ACTY20
B631
S25 DOOR R DI±770
± DIAGNOSTICSAIR SUSPENSION SYSTEM
964 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1783/83 Door Courtesy Switch Circuit
(Test Diagnosis)
CIRCUIT DESCRIPTION
The door courtesy light switch turns on when the door is opened and turns off when the door is closed.
The signal is sent from the body ECU and the back door ECU into the DOOR terminal of the suspension
control ECU when any door is open.
HINT:
This DTC is output only when the sensor signal check is done.
For courtesy light switch connection, see the system diagram on page DI±698.
DTC No.DTC Detecting ConditionTrouble Area
C1783/83Door courtesy light switch signal does not change.

Door courtesy light switch

Back door lock assy (Back door courtesy light switch)

Door courtesy light switch circuit

Body ECU

Back door ECU

Suspension control ECU
WIRING DIAGRAM
DIDEA±01

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±771
965 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
1 Inspect courtesy light switch.
CHECK:
Check that the open door warning light comes on when any door or back door is opened and goes off when
all the doors are closed.
OK:
Courtesy light operates normally.
NG Check open door warning light
(See page DI±1608).
OK

I27702
Body ECU Wire Harness View:
B6
ACTY
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±773
967 Author: Date:
2005 SEQUOIA (RM1146U)
3 Inspect body ECU (ACTY output).
PREPARATION:
Reconnect the body ECU and suspension control ECU connec-
tors.
CHECK:
Measure the voltage between terminal B6±20 (ACTY) of the
multiplex network body ECU and body ground when doors are
opened and closed.
OK:
Door conditionSpecified condition
Each door openedBelow 1.5 V
All doors closed10 to 14 V
NG Replace body ECU (See page IN±35).
OK
Replace suspension control ECU
(See page IN±35).