2001 TOYOTA SEQUOIA terminal TC

F16806
High (45°)Low (±45°)
Normal (0°)
Connector Front View:
SHG SHRLSHB
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±735
929 Author: Date:
2005 SEQUOIA (RM1146U)
5 Inspect height control sensor sub±assy.
PREPARATION:
(a) Remove the height control sensor sub±assy.
(b) Connect 3 dry batteries of 1.5 V in series.
CHECK:
Connect terminal 1 (SHB) to the batteries' positive (+) terminal,
and terminal 3 (SHG) to the batteries' negative (±) terminal,
then apply approximately 4.5 V between terminals 2 (SHRL)
and 3 (SHG) in the following conditions.
OK:
PositionVoltage
High (0 to 45)Approx. 2.25 to 4.05 V
Normal (0)Approx. 2.25 V
Low (0 to ±45)Approx. 0.45 to 2.25 V
NG Replace height control sensor sub±assy.
OK
Replace suspension control ECU
(See page IN±35).

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).

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).

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±747
941 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1741/41 Air Sus Relay Circuit
CIRCUIT DESCRIPTION
When the ºUPº side of the height control switch is pressed, a signal is sent from terminal RC of the suspen-
sion control ECU to the AIR SUS relay to turn it on.
As a result, the current flows to the AIR SUS relay coil, closing the relay contact, and then the battery positive
voltage is applied to the compressor, which causes the compressed air to raise the vehicle height.
DTC No.DTC Detecting ConditionTrouble Area
C1741/41
Either of the following conditions is detected:
1. With the AIR SUS relay inactivated, an open signal of the
AIR SUS relay is detected for 1 sec. or more.
2. With the AIR SUS relay activated, a short signal of the AIR
SUS relay is detected 8 times successively.

AIR SUS relay

AIR SUS relay circuit

Suspension control ECU
HINT:
Once the ECU stores DTC C1741/41 in the memory, the vehicle height control is suspended until a normal
signal is input to the ECU from the AIR SUS relay. However, the control resumes if the ignition switch is turned
OFF, and then turned ON again.
DIDDT±01