Lexus ES manuals

Lexus ES: Suspension Control ECU Malfunction (C1781)

Lexus ES (XZ10) Service Manual / Suspension / Suspension Control / Adaptive Variable Suspension System / Suspension Control ECU Malfunction (C1781)

DESCRIPTION

If a malfunction in the absorber control ECU is detected, DTC C1781 is stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Memory

C1781

Suspension Control ECU Malfunction

One of the following conditions is met:

  • A nonvolatile memory write or read error occurs.
  • A CAN communication register is stuck.
  • An overheat protection function malfunction occurs.
  • Absorber control ECU
  • CAN communication system

Does not come on

Yes

CAUTION / NOTICE / HINT

NOTICE:

  • Before performing troubleshooting, inspect the connectors of related circuits.
  • Before replacing the absorber control ECU, perform all of the following:
    • Symptom simulation.

      Click here

    • DTC inspection.

      Click here

    • Techstream inspection.

      Click here

      • If no malfunctions are found in other areas, replace the absorber control ECU.
  • After replacing the absorber control ECU with a new one, perform registration of vehicle identification information.

    Click here

PROCEDURE

1.

CHECK FOR DTCS (CAN COMMUNICATION SYSTEM)

(a) Check for DTCs.

Click here

Chassis > Air suspension > Trouble Codes

Result

Proceed to

CAN DTCs are not output

A

CAN DTCs are output

B
A

REPLACE ABSORBER CONTROL ECU

B

GO TO CAN COMMUNICATION SYSTEM (HOW TO PROCEED WITH TROUBLESHOOTING)

READ NEXT:

 Front Wheels Speed Sensor Signal Malfunction (C1783)

DESCRIPTION The speed sensors monitor the speed of the wheels and send an appropriate speed signal to the absorber control ECU through the skid control ECU (brake actuator assembly). If a malfunction

 Steering Sensor Signal Malfunction (C1784)

DESCRIPTION Steering sensor signals are sent to the absorber control ECU via CAN communication. If a communication error is detected, DTC C1784 is stored. DTC No. Detection Item DTC Detection C

 Master Cylinder Pressure Circuit (C1786)

DESCRIPTION The absorber control ECU stores this DTC when a malfunction signal from the master cylinder pressure sensor built into the brake actuator assembly is received via CAN communication. DTC

SEE MORE:

 If you have a flat tire

Your vehicle is equipped with a spare tire. The flat tire can be replaced with the spare tire. WARNING ■If you have a flat tire Do not continue driving with a flat tire. Driving even a short distance with a flat tire can damage the tire and the wheel beyond repair, which could result in

 Data List / Active Test

DATA LIST / ACTIVE TEST DATA LIST NOTICE: In the table below, the values listed under "Normal Condition" are reference values. Do not depend solely on these reference values when deciding whether a part is faulty or not. HINT: Using the Techstream to read the Data List allows the values or states of

© 2016-2026 Copyright www.lexguide.net