2001 TOYOTA SEQUOIA wiring diagram

DIDDK±01
F19441
SHB H15
Height Control Sensor Sub±assy
1 G±OSuspension Control ECU
SBL
BM1G±O 5
IN118
G±O
S2515
SHRL2
GR±L
BM16
IN117
S2517
GR±LGR±L
SHRL
SHG3
L±R
BM17
L±RL±R
IN116
S2519
SGL
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±731
925 Author: Date:
2005 SEQUOIA (RM1146U)
CIRCUIT INSPECTION
DTC C1714/14 Left Rear Height Control Sensor Circuit
CIRCUIT DESCRIPTION
A magnetic circuit installed on the shaft inside the height control sensor rotates around the linear IC. The
linear IC outputs voltage corresponding to the level of magnetic strength generated by the magnetic circuit.
As a result, voltage corresponding to the shaft rotation angle is supplied to the suspension control ECU.
DTC No.DTC Detecting ConditionTrouble Area
C1714/14
Either of the following conditions is detected:
1. With the ignition switch ON, a voltage of the height control
sensor sub±assy is 4.7 V or more or 0.3 V or less for 1 sec.
or more.
2. With the ignition switch ON, a voltage of the height control
sensor sub±assy is 5.5 V or more or 4.3 V or less for 0.5
sec. or more.

Height control sensor sub±assy

Height control sensor circuit

Suspension control ECU
HINT:

Once the ECU stores DTC C1714/14 in the memory, vehicle height control is suspended until a normal
signal is input to the ECU from the height control sensor sub±assy. However, control resumes if the
ignition switch is turned OFF, and then turned ON again.

When the suspension control ECU detects a malfunction in the height control sensor, the height control
indicator lamp ºNº comes on or blinks, and control of the height control sensor ºUPº and ºDOWNº opera-
tion is halted.
WIRING DIAGRAM

F19442
Suspension Control ECU H16
Gate Solenoid Valve
(Height Control Valve)
W±L8
BM1SLRL 114
IN14
S25
BI W±B 2W±LW±L DI±736
± DIAGNOSTICSAIR SUSPENSION SYSTEM
930 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1733/33 Gate Solenoid Valve Circuit
CIRCUIT DESCRIPTION
The suspension control ECU opens the gate solenoid valve (height control valve) to lead the compressed
air to the height control cylinder (pneumatic cylinder) and to raise the vehicle height.
Further, the gate solenoid valve (height control valve) opens and closes the passage between the right and
left height control cylinders (pneumatic cylinders).
The height control valve consists of a leveling solenoid valve and a gate solenoid valve.
The gate solenoid valve opens and closes the passage between the compressor and the height control cylin-
der (pneumatic cylinder).
DTC No.DTC Detecting ConditionTrouble Area
C1733/33
Either of the following conditions is detected:
1. With the height control valve inactivated, an open signal of
the height control valve is detected for 1 sec. or more.
2. With the height control valve activated, a short signal of the
valve is detected 8 times successively.

Gate solenoid valve (Height control valve)

Gate solenoid valve (Height control valve) circuit

Suspension control ECU
HINT:

Once the ECU stores DTC C1733/33 in the memory, the vehicle height control is suspended until a
normal signal is input to the ECU from the height control solenoid valves. However, control is resumed
if the ignition switch is turned OFF, then ON again.

Malfunction in the gate solenoid valve:
The height control operation is suspended, and the height control indicator lamp does not change by
operating the height control switch.
WIRING DIAGRAM
DIDDN±01

F19454
Suspension Control ECU H16
Leveling Solenoid Valve
(Height Control Valve)
LG±R4
BM1SLRR 313
IN13
S25
BI W±B 2LG±R
LG±R DI±740
± DIAGNOSTICSAIR SUSPENSION SYSTEM
934 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1734/34 Leveling Solenoid Valve Circuit
CIRCUIT DESCRIPTION
The suspension control ECU opens the leveling solenoid valve (height control valve) to lead the compressed
air to the height control cylinder (pneumatic cylinder) and to raise the vehicle height.
The height control valve consists of a leveling solenoid valve and a gate solenoid valve.
The leveling solenoid valve opens and closes the passage between the compressor and the height control
cylinder (pneumatic cylinder).
DTC No.DTC Detecting ConditionTrouble Area
C1734/34
Either of the following conditions is detected:
1. With the height control valve inactivated, an open signal of
the height control valve is detected for 1 sec. or more.
2. With the height control valve activated, a short signal of the
valve is detected 8 times successively.

Leveling solenoid valve (Height control valve)

Leveling solenoid valve (Height control valve) circuit

Suspension control ECU
HINT:

Once the ECU stores DTC C1734/34 in the memory, the vehicle height control is suspended until a
normal signal is input to the ECU from the height control solenoid valves. However, control is resumed
if the ignition switch is turned OFF, then ON again.

Malfunction in the leveling solenoid valve:
The height control operation is suspended, and the height control indicator lamp does not change by
operating the height control switch.
WIRING DIAGRAM
DIDDR±01

F19455
Suspension Control ECU Exhaust Solenoid Valve
(Height Control Compressor)
L±R5
BM2SLEX 14
IN11
S25
BI W±B 2 H14
H14L±R L±R DI±744
± DIAGNOSTICSAIR SUSPENSION SYSTEM
938 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1735/35 Exhaust Solenoid Valve Circuit
CIRCUIT DESCRIPTION
The suspension control ECU operates the exhaust solenoid valve (height control compressor), releases the
air from the height control cylinder assy (pneumatic cylinder), and lowers vehicle height.
When the vehicle height is lowered, the suspension control ECU opens the height control valve and then
operates the exhaust solenoid valve to release the compressed air to the outside.
The exhaust solenoid valve is on the compressor unit and has only one valve.
DTC No.DTC Detecting ConditionTrouble Area
C1735/35
Either of the following conditions is detected:
1. With the height control valve inactivated, an open signal of
the height control valve is detected for 1 sec. or more.
2. With the height control valve activated, a short signal of the
valve is detected 8 times successively.

Exhaust solenoid valve (Height control compressor)

Exhaust solenoid valve (Height control compressor) circuit

Suspension control ECU
HINT:

Once the ECU stores DTC C1735/35 in the memory, the vehicle height control is suspended until a
normal signal is input to the ECU from the exhaust solenoid valve. However, control is resumed if the
ignition switch is turned OFF, then ON again.

Malfunction in the exhaust solenoid valve:
The height control indicator lamp ºNº comes on or blinks, and ºHIº and ºLOº do not come on by operating
the height control switch ºUPº or ºDOWNº.
WIRING DIAGRAM
DIDDS±01

F19443
Height Control
Compressor
H131
Engine Room R/B No. 2
G±Y AIR SUS Relay
Battery J28
J/C W
BM21
IC48
IA121
WWW
2
22
2 3
25
1W
9B
5
W±B
J8
J/C
AAW±B
1K12
1F9
A W±B
IESuspension
Control
ECU
IA125
G±Y
S255
RC F10
Fusible Link Block
ALT
Instrument
Panel J/BAIR SUS DI±748
± DIAGNOSTICSAIR SUSPENSION SYSTEM
942 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

F19444
Height Control Compressor
(Compressor/Height Control Dryer)
H133
Engine Room R/B No. 2
W±B
Battery J28
J/CR±L
BM23
IN115
S2520
2
3
25
1W
9B
5
J8
J/C
AAW±B
1K12
1F9
A W±B
IESuspension
Control
ECU
RC F10
Fusible Link Block
AIR SUS
Instrument
Panel J/BRM+ R±L R±L
H134
BR±Y
BM24
IA121S2521
BR±Y BR±Y
RM±
AIR SUS Relay H131
W
BM21
IC48
WW W
22
2 S255
G±Y IN16
IA125
G±Y
BJ H132
BM22
W±B
AJ19
J/C W±BALT
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±753
947 Author: Date:
2005 SEQUOIA (RM1146U)
WIRING DIAGRAM

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±757
951 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1751/51 Continuous Electric Current To Height Con-
trol Compressor
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1751/51*1With the AIR SUS relay activated, the vehicle does not go up
to the standard vehicle height after the 90 sec. have elapsed.

Height control compressor assy

Height control compressor circuit

Height control sensor circuit

Height control sensor sub±assy

Relief valve

AIR SUS relay circuit

Air leakage from the air tube or each valve

Clogging in the air tube or each valve

Suspension control ECU
*1: The compressor motor operates continuously to raise vehicle height and allows electric current flow to
the AIR SUS relay for 90 seconds or more under the following conditions:

Vehicle height control is attempted on a steep slope when the vehicle is overloaded.

The compressor remains on for an excessive period of time or repeatedly turns on and off because
of continuous height control switch operation.

If the compressor remains on because the vehicle is jacked up, the vehicle height is set at a position
lower than normal while the engine is running and then the vehicle height control function raises the
vehicle.
Thus DTC C1751/51 may be output and vehicle height control may be suspended. (This is not electrically
abnormal.) In this case, however, the vehicle height operation is resumed approx. 10 min. after the ignition
switch is turned ON after the ECU detects the first error. If ECU detects another error, it takes 70 minutes
until control is resumed.
WIRING DIAGRAM
See page DI±752.
DIDDV±01

F19445
Engine Room R/B No. 2
F10
Fusible Link BlockSuspension Control
ECU
AIR SUS No. 2
2
1
22 W
AIR SUS
9ALT
5B
Battery
IFJ12
J/C
AW±B22
S25
GND 24
S25
25
S25
BAT B J/C
B
J37
B
J37 C
J38 V
IA55
VV
V
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±763
957 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1774/74 Power Source Circuit
CIRCUIT DESCRIPTION

This circuit provides power to operate the suspension control ECU.

The suspension control ECU, controlling the air suspension system, is activated when the ignition
switch is turned ON. The main relay inside the ECU is activated after 2 seconds and the system is oper-
ated by +B power source.
DTC No.DTC Detecting ConditionTrouble Area
C1774/74The terminal B or BAT voltage is below 10 V or above 16 V for
0.5 seconds.
Battery

Power source circuit

Suspension control ECU
WIRING DIAGRAM
DIDE3±01