Toyota Sequoia (2005). Manual - part 249

I27705

Combination Meter Wire Harness View:

C6

C6–13

F16805

Suspension Control ECU
Wire Harness View:

S25

VN

–

DIAGNOSTICS

AIR SUSPENSION SYSTEM

DI–791

985

2

Check harness and connector (Suspension control ECU – Combination meter
assy).

PREPARATION:
Disconnect the suspension control ECU connector and the
combination meter connector.
CHECK:
Measure the resistance according to the value(s) in the table
below.
OK:

Tester connection

(Symbol)

Condition

Specified condition

S25–11 (VN) – C6–13

Always

Below 1 

Ω

S25–11 (VN) –

Body ground

Always

10 k

Ω

 or higher

NG

Repair or replace harness or connector.

OK

F16805

Suspension Control ECU
Wire Harness View:

S25

VN

DI–792

–

DIAGNOSTICS

AIR SUSPENSION SYSTEM

986

3

Check combination meter.

PREPARATION:
Reconnect the combination meter connector.
CHECK:
Measure the voltage according to the value(s) in the table be-
low.
OK:

Tester connection

(Symbol)

Condition

Specified condition

S25–11 (VN) –

Body ground

Ignition switch ON

10 to 14 V

NG

Replace combination meter
(See page 

IN–35

).

OK

Replace suspension control ECU
(See page 

IN–35

).

F19452

Sub J/B No. 3

Suspension Control
ECU

Instrument Panel J/B

I18
Ignition SW

F10
FL Block

W–L

2

B

Battery

IG1

AM1

1

J37

A

J37

A

J/C

B–R

S25

10

IG

ALT

5

8

W

1L

1

AM1

1

1C

6

1C

4

ECU–IG

1F

4

B–R

8

3A

3C

8

2

B–Y

B–R

–

DIAGNOSTICS

AIR SUSPENSION SYSTEM

DI–793

987

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

DI–794

–

DIAGNOSTICS

AIR SUSPENSION SYSTEM

988

INSPECTION PROCEDURE

HINT:
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

Read value of the 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 ”IG VOLTAGE” in the DATA LIST, and read its value displayed on the hand–held tester.

AIR SUSPENSION:

Item

Measurement Item / Range (Dis-

play)

Normal Condition

Diagnostic Note

IG VOLTAGE

ECU power supply voltage / min.:

0 V, max.: 25.5 V

Actual ECU power supply voltage:

10 to 14 V

–

CHECK:
Check the ECU supply voltage.
OK:

Actual ECU power supply voltage: 10 to 14 V

OK

Proceed to next circuit inspection shown in
problem symptoms table (See page 

DI–716

).

NG