Home › Suspension › Suspension Control System › SUSPENSION CONTROL: ACTIVE HEIGHT CONTROL SUSPENSION
Last Modified: 11-27-2007 1.6 C
Service Category: Suspension Section: Suspension Control System
Model Year: 2008 Model: LX570 Doc ID: RM000003BBL001X
Title: SUSPENSION CONTROL: ACTIVE HEIGHT CONTROL SUSPENSION: DESCRIPTION (2008 LX570)

DTC

C1792

Height Control Switch Circuit (Test Mode DTC)

DESCRIPTION

This circuit sends a signal to the suspension control ECU in order to adjust the height to the selected height by the height control switch.

DTC Code

Detection Condition

Trouble Area

C1792

The test mode procedure is performed.
  • Harness or connector
  • Integration control and panel (Height control switch)
  • Suspension control ECU

WIRING DIAGRAM

INSPECTION PROCEDURE

NOTICE:

PROCEDURE

1.

READ VALUE USING TECHSTREAM (HEIGHT CONTROL SWITCH (UP), HEIGHT CONTROL SWITCH (DOWN))

(a) Turn the engine switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the engine switch on (IG) and the Techstream on.

(d) Enter the following menus: Chassis / AHC / Data List.

(e) According to the display on the Techstream, read the Data List.

AHC

Tester Display

Measurement Item/Range

Normal Condition

Diagnostic Note

Height Control Switch(Up)

Height control switch (Up) /

ON or OFF

ON: Up button of height control switch pushed

OFF: Height control switch not pushed

-

Height Control Switch(Down)

Height control switch (Down) /

ON or OFF

ON: Down button of height control switch pushed

OFF: Height control switch not pushed

-

OK:

On the Techstream screen, item changes between ON and OFF according to switch operation.

OK

2.

TEST MODE INSPECTION

(a) Refer to the Test Mode Procedure and perform the signal check. Check that test mode DTC C17912 is cleared SUSPENSION CONTROL: ACTIVE HEIGHT CONTROL SUSPENSION: TEST MODE PROCEDURE (2008 LX570) .

Result

Result

Proceed to

DTC C1792 is not cleared

A

DTC C1792 is cleared

B
A

3.

INSPECT INTEGRATION CONTROL AND PANEL (HEIGHT CONTROL SWITCH)

(a) Remove the integration control and panel SUSPENSION CONTROL: ABSORBER CONTROL SWITCH: REMOVAL (2008 LX570) .

(b) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Switch Condition

Specified Condition

12 (LO) - 6 (E)

Down button of the height control switch is pushed.

Below 1 Ω

Height control switch is not pushed or the up button is pushed.

10 kΩ or higher

8 (HI) - 6 (E)

Up button of the height control switch is pushed.

Below 1 Ω

Height control switch is not pushed or the down button is pushed.

10 kΩ or higher
OK

4.

CHECK HARNESS AND CONNECTOR (SUSPENSION CONTROL ECU - SWITCH AND BODY GROUND)


(a) Disconnect the K30 ECU connector.

(b) Disconnect the V4 integration control and panel connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

K30-20 (UPSW) - V4-8 (HI)

Always

Below 1 Ω

K30-20 (UPSW) - Body ground

Always

10 kΩ or higher

K30-21 (DNSW) - V4-12 (LO)

Always

Below 1 Ω

K30-21 (DNSW) - Body ground

Always

10 kΩ or higher

V4-6 (E) - Body ground

Always

Below 1 Ω
OK