2001 TOYOTA SEQUOIA Page 18

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±737
931 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:

If DTC C1761/61 (ECU malfunction) and/or C1774/74 (power source circuit) is displayed, perform the
inspection necessary for DTC C1761/61 (See page DI±761) and/or C1774/74 (See page DI±763) first.
(If DTC C1761/61 and the C1774/74 are output at the same time, perform the inspection necessary
for DTC C1774/74 first.)

Start the inspection from step 1 when using the hand±held tester, and start from step 2 when not using
the hand±held tester.
1 Perform active test using 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 ºGATE SOL REARº in the ACTIVE TEST, and operate it with the hand±held tester.
AIR SUSPENSION:
ItemVehicle Condition / Test DetailsDiagnostic Note
GATE SOL REARTurn gate solenoid valve / ON or OFFOperation sound of solenoid (clicking sound) can
be heard
CHECK:
(a) Check whether the solenoid makes sound.
(b) Check whether the height control valve has continuity (will vibrate).
OK:
The solenoid makes sound, and the height control valve has continuity (will vibrate).
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 Replace suspension control ECU
(See page IN±35).
A

F19437
Connector Front View:
32 1
DI±738
± DIAGNOSTICSAIR SUSPENSION SYSTEM
932 Author: Date:
2005 SEQUOIA (RM1146U)
2 Inspect gate solenoid valve (height control valve).
PREPARATION:
Disconnect the valve connector.
CHECK:
Measure the resistance between terminals.
OK:
Solenoid valveTester connectionResistance
Gate solenoid valve1 ± 217.5 to 21.5 W
CHECK:
Check the operating sound of the valves when battery voltage
is applied to the terminals as shown below.
Solenoid valveBattery positiveBattery negative
Gate solenoid valve12
OK:
Operating sound (clicking) can be heard.
HINT:
When a malfunction is found in the gate solenoid valve, replace
the height control valve.
NG Replace height control valve
(See page SA±166).
OK

F16805
Suspension Control ECU
Wire Harness View:
S25
SLRL
F19436
Height Control Valve
Wire Harness View:
H16
321
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±739
933 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check harness and connector (Height control valve ± Suspension control ECU,
Body ground).
PREPARATION:
Disconnect the ECU connector.
CHECK:
Check for an open or short circuit in the harness and the con-
nectors between terminal 1 of the height control valve and ter-
minal S25±4 (SLRL) of the suspension control ECU.
OK:
There is no open or short in the wire harness.
CHECK:
Check for an open circuit in the harness and the connectors be-
tween terminal 2 of the height control valve and body ground.
OK:
There is no open in the wire harness.
NG Repair or replace harness or connector.
OK
Replace suspension control ECU
(See page IN±35).

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±741
935 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:

If DTC C1761/61 (ECU malfunction) and/or C1774/74 (power source circuit) is displayed, perform the
inspection necessary for DTC C1761/61 (See page DI±761) and/or C1774/74 (See page DI±763) first.
(If DTC C1761/61 and the C1774/74 are output at the same time, perform the inspection necessary
for DTC C1774/74 first.)

Start the inspection from step 1 when using the hand±held tester, and start from step 2 when not using
the hand±held tester
1 Perform active test using 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 ºLEVEL SOL REARº in the ACTIVE TEST, and operate it with the hand±held tester.
AIR SUSPENSION:
ItemVehicle Condition / Test DetailsDiagnostic Note
LEVEL SOL REARTurn leveling solenoid valve / ON or OFFOperation sound of solenoid (clicking sound) can
be heard
CHECK:
(a) Check whether the solenoid makes sound.
(b) Check whether the height control solenoid valve has continuity (will vibrate).
OK:
The solenoid makes sound, and the height control solenoid valve has continuity (will vibrate).
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 Replace suspension control ECU
(See page IN±35).
A

F19437
Connector Front View:
32 1
DI±742
± DIAGNOSTICSAIR SUSPENSION SYSTEM
936 Author: Date:
2005 SEQUOIA (RM1146U)
2 Inspect leveling solenoid valve (height control valve).
PREPARATION:
Disconnect the valve connector.
CHECK:
Measure the resistance between terminals.
OK:
Solenoid valveTester connectionResistance
Leveling solenoid valve2 ± 310 to 14 W
CHECK:
Check the operating sound of the valves when battery voltage
is applied to the terminals as shown below.
Solenoid valveBattery positiveBattery negative
Leveling solenoid valve32
OK:
Operating sound (clicking) can be heard.
HINT:
When a malfunction is found in the the leveling solenoid valve,
replace the height control valve.
NG Replace height control valve
(See page SA±166).
OK

F16805
S25
Suspension Control ECU
Wire Harness View:
SLRR
F19436
Height Control Valve
Wire Harness View:
H16
321
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±743
937 Author: Date:
2005 SEQUOIA (RM1146U)
3 Check harness and connector (Height control valve ± Suspension control ECU,
Body ground).
PREPARATION:
Disconnect the ECU connector.
CHECK:
Check for an open or short circuit in the harness and the con-
nectors between terminal 3 of the height control valve and ter-
minal S25±3 (SLRR) of the suspension control ECU.
OK:
There is no open or short in the wire harness.
CHECK:
Check for an open circuit in the harness and the connectors be-
tween terminal 2 of the height control valve and body ground.
OK:
There is no open in the wire harness.
NG Repair or replace harness or connector.
OK
Replace suspension control ECU
(See page IN±35).

F19457
Connector Front View:
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±745
939 Author: Date:
2005 SEQUOIA (RM1146U)
INSPECTION PROCEDURE
HINT:

If DTC C1761/61 (ECU malfunction) and/or C1774/74 (power source circuit) is displayed, perform the
inspection necessary for DTC C1761/61 (See page DI±761) and/or C1774/74 (See page DI±763) first.
(If DTC C1761/61 and the C1774/74 are output at the same time, perform the inspection necessary
for DTC C1774/74 first.)
1 Inspect exhaust solenoid valve (height control compressor).
PREPARATION:
Disconnect the valve connector.
CHECK:
Measure the resistance between terminals.
OK:
Solenoid valveTester connectionResistance
Exhaust solenoid valve1 ± 210 to 14 W
CHECK:
Check the operating sound of the valves when battery voltage
is applied to the terminals as shown below.
Solenoid valveBattery positiveBattery negative
Exhaust solenoid valve12
OK:
Operating sound (clicking) can be heard.
HINT:
When a malfunction is found in the exhaust solenoid valve, re-
place the height control compressor.
NG Replace height control compressor assy
(See page SA±162).
OK

F16805
S25
Suspension Control ECU
Wire Harness View:
SLEX
F19459
Height Control Compressor
Connector Front View:
H14
DI±746
± DIAGNOSTICSAIR SUSPENSION SYSTEM
940 Author: Date:
2005 SEQUOIA (RM1146U)
2 Check harness and connector (Height control compressor ± Suspension control
ECU, Body ground).
PREPARATION:
Disconnect the ECU connector.
CHECK:
Check for an open or short circuit in the harness and the con-
nectors between terminal 1 of the height control compressor
and terminal S25±1 (SLEX) of the suspension control ECU.
OK:
There is no open or short in the wire harness.
CHECK:
Check for an open circuit in the harness and the connectors be-
tween terminal 2 of the height control compressor and body
ground.
OK:
There is no open in the wire harness.
NG Repair or replace harness or connector.
OK
Replace suspension control ECU
(See page IN±35).