Toyota Sequoia (2005). Manual - part 246

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DIAGNOSTICS

AIR SUSPENSION SYSTEM

DI–779

973

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 turn the hand–held tester main switch ON.

(c)

Select the item ”HEIGHT SW HOLD” 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

HEIGHT SW HOLD

Height control mode select switch

/ ON or OFF

ON: Height control mode select

switch is pressed 

OFF: –

–

CHECK:
Check that the value displayed on the hand–held tester changes by pressing the height control mode select
switch.
OK:

Height control mode select switch value changes.

RESULT:

NG

A

OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE)

B

OK (When troubleshooting according to the DTC chart)

C

B

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

DI–716

).

C

Replace suspension control ECU
(See page 

IN–35

).

A

F19434

4

3

Height Control Mode Select Switch

Pushed In

Free

DI–780

–

DIAGNOSTICS

AIR SUSPENSION SYSTEM

974

2

Inspect height control mode select switch.

PREPARATION:
Disconnect the height control mode select switch connector.
CHECK:
Check continuity between terminals 3 and 4 of the height con-
trol mode select switch when the height control mode select
switch is pushed in and free.
OK:

Switch condition

Specification

Pushed in

Continuity

Free

No continuity

NG

Replace height control mode select switch.

OK

F16805

Suspension Control ECU
Wire Harness View:

S25

TD

F19463

Height Control Mode Select Switch
Wire Harness Connector Front View:

H17

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DIAGNOSTICS

AIR SUSPENSION SYSTEM

DI–781

975

3

Check harness and connector (Height control mode select switch – Suspension
control ECU).

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

Tester connection

(Symbol)

Condition

Specified condition

S25–12 (TD) – H17–3

Always

Below 1 

Ω

H17–4 – Body ground

Always

Below 1 

Ω

S25–12 (TD) – 

Body ground

Always

10 k

Ω

 or higher

NG

Repair or replace harness or connector.

OK

Replace suspension control ECU
(See page 

IN–35

).

DI–782

–

DIAGNOSTICS

AIR SUSPENSION SYSTEM

976

DTC

U0100/65 Lost Communication with ECM/PCM

CIRCUIT DESCRIPTION

The ECM sends signals such as engine speed signal, transmission signal, shift position signal, L4 switch
signal, TC terminal signal (diagnosis mode signal) to the suspension control ECU, etc. when the air suspen-
sion system is in operation.

DTC No.

DTC Detecting Condition

Trouble Area

U0100/65

The suspension control ECU detects the following conditions

simultaneously:

1. Ignition switch ON

2. Vehicle speed signal is more than 30 km/h (18.5 mph)

3. No communication from ECM continues for more than 3

seconds

ECM

Suspension control ECU

Communication circuit

INSPECTION PROCEDURE

HINT:
This circuit uses CAN for communication. Therefore, if there are any malfunctions in the communication cir-
cuit, one or more DTCs in the CAN communication system is/are output.

1

Go to CAN communication system (See page 

DI–1065

).

DIDEG–01