2001 TOYOTA SEQUOIA relay

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

± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±761
955 Author: Date:
2005 SEQUOIA (RM1146U)
DTC C1761/61 ECU Malfunction
CIRCUIT DESCRIPTION
DTC No.DTC Detecting ConditionTrouble Area
C1761/61Suspension control ECU malfunction

Power source circuit

Suspension control ECU

Communication circuit
INSPECTION PROCEDURE
HINT:

If DTC C1774/74 (power source circuit) is displayed, perform the inspection necessary for DTC
C1774/74 first (See page DI±763).

If DTC U0122/67, U0100/65, U0132/71 and C1761/61 (ECU malfunction) are output at the same time,
perform the inspection necessary for the CAN communication system first.

The suspension control ECU, controlling the air suspension system, is activated when the ignition
switch is turned ON.
After 2 seconds, the ºMAIN RELAYº built in the ECU is activated and the system is driven by +B power
source.
Vehicle height may increase after turning the ignition switch off and unloading the vehicle/letting
people get out of the vehicle. In order to adjust the vehicle height, vehicle height control will continue
for a while from then.
DIDDY±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

F19452
Sub J/B No. 3Suspension Control
ECU
Instrument Panel J/BI18
Ignition SW
F10
FL BlockW±L 2
B
Battery IG1AM11 J37
AJ37
A J/C
B±R
S2510
IG
ALT5 8 W1L1
AM1
11C6 1C4 ECU±IG
1F4 B±R8
3A3C8
2B±YB±R
± DIAGNOSTICSAIR SUSPENSION SYSTEM
DI±793
987 Author: Date:
2005 SEQUOIA (RM1146U)
IG Signal Circuit
CIRCUIT DESCRIPTION
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 operated by +B power source.
WIRING DIAGRAM
DIDEO±01

DIDLV±01
F17996
Front Speed SensorABS & VSC Actuator
(w/ Skid Control ECU)Level Warning Switch
Rear Speed Sensor Rear Speed Sensor Rotor
Front Speed
Sensor Rotor
Parking Brake SwitchStop Light Switch
Center Diff. Lock Switch *1
TRAC OFF Switch *2
Steering Angle Sensor
DLC3Brake Inhibit RelayTranslate ECU
VSC BuzzerBrake Booster
(Including Active Brake Booster
Solenoid, Delta S Sensor and Boost-
er Pedal Switch)
Master Cylinder
Pressure Sensor
Front Speed Sensor Rotor
Front Speed Sensor
Yaw Rate Sensor
(Including Deceleration Sensor)
ABS Warning Light
VSC TRAC Warning light
VSC OFF Indicator Light *
1
TRAC OFF Indicator Light *2
BRAKE Warning Light
SLIP Indicator Light
*1: Only for 4WD
*2: Only for 2WDCenter Diff. Lock
Position Switch
DI±892
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1086 Author: Date:
2005 SEQUOIA (RM1146U)
LOCATION

DIDM0±01
F16974
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
DI±907
1101 Author: Date:
2005 SEQUOIA (RM1146U)
TERMINALS OF ECU
1. Skid Control ECU:
Symbols (Terminal No.)Terminal Description
GND (1)Skid control ECU ground
CANL (2)Vehicle CAN communication line
VCP (3)Pedal stroke sensor (Delta S Sensor) line
CANH (6)Vehicle CAN communication line
E3 (8)Pedal stroke sensor (Delta S Sensor) ground
VYS (11)Yaw rate sensor power source
IG1 (13)IG1 power supply
PIM (14)Pedal stroke sensor (Delta S Sensor) line
D/G (15)Diagnosis tester communication line
+BM (16)Motor relay power supply
BST (17)Brake booster line
PSNC (18)Brake booster line
SS1 (19)Yaw rate sensor signal line
STS (20)Brake booster line
PSNO (21)Brake booster line
BZ (22)Buzzer output
SS2 (23)Yaw rate sensor signal line
GYAW (24)Yaw rate sensor ground
PMC2 (25)M/C pressure sensor 2 signal
VCM2 (26)M/C pressure sensor 2 power supply
E2 (27)M/C pressure sensor 2 ground
PMC (28)M/C pressure sensor 1 signal
E1 (29)M/C pressure sensor 1 ground
VCM (30)M/C pressure sensor 1 power supply
BSTP (31)Brake booster line
GND2 (32)Skid control ECU ground
FL+ (33)FL wheel speed signal line
FL± (34)FL wheel speed signal line
WA (35)ABS warning light output
RR± (36)RR wheel speed signal line
RR+ (37)RR wheel speed signal line
BSW (38)Brake inhibit signal line
STP (39)Stop light switch signal input

F19198
Skid Control ECU
(harness side connector) DI±908
± DIAGNOSTICSABS WITH EBD & BA & TRAC & VSC SYSTEM
1102 Author: Date:
2005 SEQUOIA (RM1146U)Symbols (Terminal No.) Terminal Description
TS (40)Sensor check input
+BO (41)Steering angle sensor line
RL+ (42)RL wheel speed signal line
RL± (43)RL wheel speed signal line
VSCW (44)VSC OFF indicator output
FR± (45)FR wheel speed signal line
FR+ (46)FR wheel speed signal line
+BS (47)Solenoid relay power supply
2. Terminal Inspection
Disconnect the connector and measure the voltage on the wire harness side.
HINT:
Voltage can not be measured with the connector connected to the skid control ECU as the connector is water
resistance.
Symbols (Terminal No.)Wiring ColorTerminal DescriptionConditionSpecified Condition
+BM (16) ± GND1, 2 (1, 32)B±R ± W±BMotor relay power supplyIG switch ON10 to 14 V
GYAW (24) ± GND1, 2 (1, 32)G ± W±BYaw rate sensor groundAlwaysBelow 1 W
E3 (8) ± GND1, 2 (1, 32)L ± W±BM/C pressure sensor 3
groundAlwaysBelow 1 W
E2 (27) ± GND1, 2 (1, 32)W ± W±BM/C pressure sensor 2
groundAlwaysBelow 1 W
E1 (29) ± GND1, 2 (1, 32)W ± W±BM/C pressure sensor 1
groundAlwaysBelow 1 W
STP (39) ± GND1, 2 (1, 32)G±Y ± W±BStop light switch signal in-
putBrake pedal depressed8 to 14 V
STP (39) ± GND1, 2 (1, 32)G±Y ± W±BStop light switch signal in-
putBrake pedal releasedBelow 1.5 V
+BS (47) ± GND1, 2 (1, 32)B±R ± W±BSolenoid relay power sup-
plyIG switch ON10 to 14 V