Toyota Sequoia (2005). Manual - part 237

F16805

S25

Suspension Control ECU 
Wire Harness View:

SLRR

F19436

Height Control Valve 
Wire Harness View:

H16

3

2 1

–

DIAGNOSTICS

AIR SUSPENSION SYSTEM

DI–743

937

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

).

F19455

Suspension Control ECU

Exhaust Solenoid Valve
(Height Control Compressor)

L–R

5

BM2

SLEX

1

4

IN1

1

S25

BI

W–B

2

H14

H14

L–R

L–R

DI–744

–

DIAGNOSTICS

AIR SUSPENSION SYSTEM

938

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 Condition

Trouble 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 ”N” comes on or blinks, and ”HI” and ”LO” do not come on by operating
the height control switch ”UP” or ”DOWN”.

WIRING DIAGRAM

DIDDS–01

F19457

Connector Front View:

–

DIAGNOSTICS

AIR SUSPENSION SYSTEM

DI–745

939

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 valve

Tester connection

Resistance

Exhaust solenoid valve

1 – 2

10 to 14 

Ω

CHECK:
Check the operating sound of the valves when battery voltage
is applied to the terminals as shown below.

Solenoid valve

Battery positive

Battery negative

Exhaust solenoid valve

1

2

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

–

DIAGNOSTICS

AIR SUSPENSION SYSTEM

940

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

).