Lexus NX manuals

Lexus NX: Front Damping Force Control Actuator RH Circuit Malfunction (C1731-C1734)

Lexus NX Service Manual / Suspension / Suspension Control / Adaptive Variable Suspension System / Front Damping Force Control Actuator RH Circuit Malfunction (C1731-C1734)

DESCRIPTION

The absorber control actuator changes the damping force depending on absorber control ECU signals.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

C1731

Front Damping Force Control Actuator RH Circuit Malfunction

Either condition is met:

  • An open circuit is detected between the front absorber control actuator RH (front shock absorber assembly RH) and absorber control ECU.
  • A short circuit is detected between the front absorber control actuator RH (front shock absorber assembly RH) and absorber control ECU.
  • Front absorber control actuator RH (front shock absorber assembly RH)
  • Front skid control sensor wire RH
  • Harness or connector
  • Absorber control ECU

Does not come on

C1732

Front Damping Force Control Actuator LH Circuit Malfunction

Either condition is met:

  • An open circuit is detected between the front absorber control actuator LH (front shock absorber assembly LH) and absorber control ECU.
  • A short circuit is detected between the front absorber control actuator LH (front shock absorber assembly LH) and absorber control ECU.
  • Front absorber control actuator LH (front shock absorber assembly LH)
  • Front skid control sensor wire LH
  • Harness or connector
  • Absorber control ECU

Does not come on

C1733

Rear Damping Force Control Actuator RH Circuit Malfunction

Either condition is met:

  • An open circuit is detected between the rear absorber control actuator RH (rear shock absorber assembly RH) and absorber control ECU.
  • A short circuit is detected between the rear absorber control actuator RH (rear shock absorber assembly RH) and absorber control ECU.
  • Rear absorber control actuator RH (rear shock absorber assembly RH)
  • Rear speed sensor RH
  • Harness or connector
  • Absorber control ECU

Does not come on

C1734

Rear Damping Force Control Actuator LH Circuit Malfunction

Either condition is met:

  • An open circuit is detected between the rear absorber control actuator LH (rear shock absorber assembly LH) and absorber control ECU.
  • A short circuit is detected between the rear absorber control actuator LH (rear shock absorber assembly LH) and absorber control ECU.
  • Rear absorber control actuator LH (rear shock absorber assembly LH)
  • Rear speed sensor LH
  • Harness or connector
  • Absorber control ECU

Does not come on

WIRING DIAGRAM

CAUTION / NOTICE / HINT

NOTICE:

  • Before performing troubleshooting, inspect the connectors of related circuits.
  • If DTC C1782 (Power Source Voltage Malfunction) is output at the same time, perform troubleshooting for C1782 first.

    Click here

  • Before replacing the absorber control ECU, perform all of the following again: 1) symptom simulation ; 2) DTC inspection ; and 3) Techstream inspection (ECU Data List or Active Test ). If no malfunctions are found in other areas, replace the absorber control ECU.
  • When the absorber control ECU is replaced, switch to test mode and check that all test mode DTCs are cleared when their respective deletion conditions are met.

    Click here

PROCEDURE

1.

CLEAR DTC

(a) Clear the DTCs.

Click here

Chassis > Air suspension > Clear DTCs
NEXT

2.

PERFORM ACTIVE TEST USING TECHSTREAM (DAMPER STEP)

(a) Turn the power switch off.

(b) Connect the Techstream to the DLC3.

(c) Turn the power switch on (READY).

(d) Turn the Techstream on.

(e) Enter the following menus: Chassis / Air suspension /Active Test.

Chassis > Air suspension > Active Test

Tester Display

Measurement Item

Control Range

Diagnostic Note

Damper Step FR

Changes damper step (front RH)

1 to 30 step

The shock absorber hardens as the damper step increases.

Damper Step FL

Changes damper step (front LH)

1 to 30 step

The shock absorber hardens as the damper step increases.

Damper Step RR

Changes damper step (rear RH)

1 to 30 step

The shock absorber hardens as the damper step increases.

Damper Step RL

Changes damper step (rear LH)

1 to 30 step

The shock absorber hardens as the damper step increases.
Chassis > Air suspension > Active Test

Tester Display

Damper Step FR
Chassis > Air suspension > Active Test

Tester Display

Damper Step FL
Chassis > Air suspension > Active Test

Tester Display

Damper Step RR
Chassis > Air suspension > Active Test

Tester Display

Damper Step RL

(f) When performing the Active Test, read each Tester Display item for the applicable wheel on the Data List and check the operation status of the absorber control actuator for the applicable wheel.

Chassis > Air suspension > Data List

Tester Display

Measurement Item

Range

Normal Condition

Diagnostic Note

Damper Step FR

Damper step (front RH)

Min.: 1 step

Max.: 255 step

1 to 30 step

-

Damper Step FL

Damper step (front LH)

Min.: 1 step

Max.: 255 step

1 to 30 step

-

Damper Step RR

Damper step (rear RH)

Min.: 1 step

Max.: 255 step

1 to 30 step

-

Damper Step RL

Damper step (rear LH)

Min.: 1 step

Max.: 255 step

1 to 30 step

-

FR Solenoid Aim Electric Current Level for Control

Target solenoid current value (front wheel RH)

Min.: 0 mA

Max.: 2040 mA

Changes depending on step count

-

FL Solenoid Aim Electric Current Level for Control

Target solenoid current value (front wheel LH)

Min.: 0 mA

Max.: 2040 mA

Changes depending on step count

-

RR Solenoid Aim Electric Current Level for Control

Target solenoid current value (rear wheel RH)

Min.: 0 mA

Max.: 2040 mA

Changes depending on step count

-

RL Solenoid Aim Electric Current Level for Control

Target solenoid current value (rear wheel LH)

Min.: 0 mA

Max.: 2040 mA

Changes depending on step count

-

FR Solenoid Drive Duty

Solenoid drive duty value (front wheel RH)

Min.: 0%

Max.: 100%

Changes depending on step count

-

FL Solenoid Drive Duty

Solenoid drive duty value (front wheel LH)

Min.: 0%

Max.: 100%

Changes depending on step count

-

RR Solenoid Drive Duty

Solenoid drive duty value (rear wheel RH)

Min.: 0%

Max.: 100%

Changes depending on step count

-

RL Solenoid Drive Duty

Solenoid drive duty value (rear wheel LH)

Min.: 0%

Max.: 100%

Changes depending on step count

-

FR Solenoid Electric Current

Solenoid current value (front wheel RH)

Min.: 0 mA

Max.: 2040 mA

Changes depending on step count

-

FL Solenoid Electric Current

Solenoid current value (front wheel LH)

Min.: 0 mA

Max.: 2040 mA

Changes depending on step count

-

RR Solenoid Electric Current

Solenoid current value (rear wheel RH)

Min.: 0 mA

Max.: 2040 mA

Changes depending on step count

-

RL Solenoid Electric Current

Solenoid current value (rear wheel LH)

Min.: 0 mA

Max.: 2040 mA

Changes depending on step count

-
Chassis > Air suspension > Data List

Tester Display

Damper Step FR

Damper Step FL

Damper Step RR

Damper Step RL

FR Solenoid Aim Electric Current Level for Control

FL Solenoid Aim Electric Current Level for Control

RR Solenoid Aim Electric Current Level for Control

RL Solenoid Aim Electric Current Level for Control

FR Solenoid Drive Duty

FL Solenoid Drive Duty

RR Solenoid Drive Duty

RL Solenoid Drive Duty

FR Solenoid Electric Current

FL Solenoid Electric Current

RR Solenoid Electric Current

RL Solenoid Electric Current

OK:

The Data List step numbers, drive duty values and current values change according to the Techstream Active Test operation.

NG

GO TO STEP 4

OK

3.

RECONFIRM DTC

(a) Check that the same DTC is output.

Click here

Chassis > Air suspension > Trouble Codes

Result

Proceed to

DTC is output

A

DTC is not output

B
B

USE SIMULATION METHOD TO CHECK

A

4.

INSPECT SHOCK ABSORBER ASSEMBLY

(a) Turn the power switch off.

(b) Remove the absorber control actuator (shock absorber assembly).

for Front Side: Click here

for Rear Side: Click here

(c) Inspect the absorber control actuator (shock absorber assembly).

for Front Side: Click here

for Rear Side: Click here

Result

Proceed to

OK (for Front Side)

A

OK (for Rear Side)

B

Front absorber control actuator RH (front shock absorber assembly RH) malfunction

C

Front absorber control actuator LH (front shock absorber assembly LH) malfunction

D

Rear absorber control actuator RH (rear shock absorber assembly RH) malfunction

E

Rear absorber control actuator LH (rear shock absorber assembly LH) malfunction

F
B

GO TO STEP 7

C

REPLACE FRONT SHOCK ABSORBER ASSEMBLY RH

D

REPLACE FRONT SHOCK ABSORBER ASSEMBLY LH

E

REPLACE REAR SHOCK ABSORBER ASSEMBLY RH

F

REPLACE REAR SHOCK ABSORBER ASSEMBLY LH

A

5.

INSPECT FRONT SKID CONTROL SENSOR WIRE

(a) Turn the power switch off.

(b) Disconnect the A75 or A76 front skid control sensor wire connector.

(c) Disconnect the C or D front skid control sensor wire connector.

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

*A

for RH

*B

for LH

*1

Front Skid Control Sensor Wire

-

-

*a

Front view of wire harness connector

(to Vehicle Side Connector)

*b

Front view of wire harness connector

(to Front Absorber Control Actuator Side Connector)

Standard Resistance:

for Front RH

Tester Connection

Condition

Specified Condition

A75-2 (FAR+) - C-2

Always

Below 1 Ω

A75-1 (FAR-) - C-1

Always

A75-2 (FAR+) or C-2 - Body ground and other terminals

Always

10 kΩ or higher

A75-1 (FAR-) or C-1 - Body ground and other terminals

Always
for Front LH:

Tester Connection

Condition

Specified Condition

A76-2 (FAL+) - D-2

Always

Below 1 Ω

A76-1 (FAL-) - D-1

Always

A76-2 (FAL+) or D-2 - Body ground and other terminals

Always

10 kΩ or higher

A76-1 (FAL-) or D-1- Body ground and other terminals

Always
NG

REPLACE FRONT SKID CONTROL SENSOR WIRE

OK

6.

CHECK HARNESS AND CONNECTOR (FRONT SHOCK ABSORBER ASSEMBLY - ABSORBER CONTROL ECU)

(a) Turn the power switch off.

(b) Disconnect the Q22 absorber control ECU connector.

(c) Connect the A75 or A76 front skid control sensor wire connector.

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

Standard Resistance:

for Front RH

Tester Connection

Condition

Specified Condition

Q22-5 (FAR+) - C-2

Always

Below 1 Ω

Q22-6 (FAR-) - C-1

Q22-5 (FAR+) or C-2 - Body ground

Always

10 kΩ or higher

Q22-6 (FAR-) or C-1 - Body ground
for Front LH

Tester Connection

Condition

Specified Condition

Q22-2 (FAL+) - D-2

Always

Below 1 Ω

Q22-3 (FAL-) - D-1

Q22-2 (FAL+) or D-2 - Body ground

Always

10 kΩ or higher

Q22-3 (FAL-) or D-1 - Body ground
OK

REPLACE ABSORBER CONTROL ECU

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

7.

INSPECT REAR SKID CONTROL SENSOR WIRE OR REAR SPEED SENSOR

(a) Turn the power switch off.

(b) Disconnect the P2 or Q2 rear speed sensor connector.

(c) Disconnect the E or F rear speed sensor connector.

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

Standard Resistance:

for Rear RH

Tester Connection

Condition

Specified Condition

P2-1 (RAR+) - E-1

Always

Below 1 Ω

P2-2 (RAR-) - E-3

Always

P2-1 (RAR+) or E-1 - Body ground and other terminals

Always

10 kΩ or higher

P2-2 (RAR-) or E-3 - Body ground and other terminals

Always
for Rear LH

Tester Connection

Condition

Specified Condition

Q2-1 (RAL+) - F-1

Always

Below 1 Ω

Q2-2 (RAL-) - F-3

Always

Q2-1 (RAL+) or F-1- Body ground and other terminals

Always

10 kΩ or higher

Q2-2 (RAL-) or F-3 - Body ground and other terminals

Always

*A

for RH

*B

for LH

*1

Rear Speed Sensor

*a

Front view of wire harness connector

(to Vehicle Side Connector)

*b

Front view of wire harness connector

(to Rear Absorber Control Actuator Side Connector)
NG

REPLACE REAR SPEED SENSOR

OK

8.

CHECK HARNESS AND CONNECTOR (REAR SHOCK ABSORBER ASSEMBLY - ABSORBER CONTROL ECU)

(a) Turn the power switch off.

(b) Disconnect the Q21 absorber control ECU connector.

(c) Connect the P2 or Q2 rear speed sensor connector.

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

Standard Resistance:

for Rear RH

Tester Connection

Condition

Specified Condition

Q21-6 (RAR+) - E-1

Always

Below 1 Ω

Q21-5 (RAR-) - E-3

Q21-6 (RAR+) or E-1 - Body ground

Always

10 kΩ or higher

Q21-5 (RAR-) or E-3 - Body ground
for Rear LH

Tester Connection

Condition

Specified Condition

Q21-2 (RAL+) - F-1

Always

Below 1 Ω

Q21-1 (RAL-) - F-3

Q21-2 (RAL+) or F-1 - Body ground

Always

10 kΩ or higher

Q21-1 (RAL-) or F-3 - Body ground
OK

REPLACE ABSORBER CONTROL ECU

NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

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