Lexus ES manuals

Lexus ES: Assist Map Number Un-Writing (C1581)

DESCRIPTION

This DTC will be stored if the power steering ECU (rack and pinion power steering gear assembly) determines that the assist map is not written in the ECU.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

Warning Indicate

Return-to-normal Condition

Note

C1581

Assist Map Number Un-Writing

Assist map not written in power steering ECU (rack and pinion power steering gear assembly)

  • CAN communication system
  • ECM
  • Skid control ECU (Brake actuator assembly)
  • AVS ECU (Absorber control ECU) (w/ Adaptive Variable Suspension System)
  • Rack and pinion power steering gear assembly

EPS warning light: Comes on

Assist Map Writing is performed

-

CAUTION / NOTICE / HINT

NOTICE:

If the rack and pinion power steering gear assembly has been replaced, perform assist map writing and torque sensor zero point calibration.

Click here

HINT:

Related parts store information necessary for assist map writing.

Related Part:

  • ECM
  • Skid control ECU (Brake actuator assembly)
  • AVS ECU (Absorber control ECU) (w/ Adaptive Variable Suspension System)

PROCEDURE

1.

PERFORM ASSIST MAP WRITING

(a) Perform assist map writing.

Chassis > EMPS > Utility

Tester Display

Signal Check

(b) Check for DTCs.

Chassis > EMPS > Trouble Codes

Result

Proceed to

DTC C1581 is output.

A

DTC C1581 is not output.

B

B

END

A

2.

CHECK CAN COMMUNICATION SYSTEM

(a) Check for DTCs.

Click here

Result

Proceed to

CAN communication system DTCs are not output.

A

CAN communication system DTCs are output.

B

B

GO TO CAN COMMUNICATION SYSTEM

A

3.

CHECK RELATED PART

(a) Confirm if the related part has the correct part number.

Related Part

ECM

Skid control ECU (Brake actuator assembly)

AVS ECU (Absorber control ECU) (w/ Adaptive Variable Suspension System)

NOTICE:

When removing the related part to check it, be sure to follow the appropriate procedures and precautions.

  • ECM

    Click here

  • Skid control ECU (Brake actuator assembly)

    Click here

  • AVS ECU (Absorber control ECU) (w/ Adaptive Variable Suspension System)

    Click here

Result

Proceed to

The related part has the correct part number.

A

The related part has an incorrect part number.

B

B

GO TO STEP 5

A

4.

CHECK FOR DTC

(a) Select Health Check on the Techstream screen and check if system DTCs of the related part are output.

HINT:

If system DTCs of the related part are stored, assist map writing to the power steering ECU (rack and pinion power steering gear assembly) may not be performed properly.

Result

Proceed to

System DTCs of the related part are output.

A

System DTCs of the related part are not output.

B

A

REPAIR CIRCUIT INDICATED BY OUTPUT CODE

B

REPLACE RACK AND PINION POWER STEERING GEAR ASSEMBLY

5.

REPLACE RELATED PART WITH PART THAT HAS CORRECT PART NUMBER

(a) Replace the related part with one that has the correct part number.

  • ECM

    Click here

  • Skid control ECU (Brake actuator assembly)

    Click here

  • AVS ECU (Absorber control ECU) (w/ Adaptive Variable Suspension System)

    Click here

NEXT

6.

CHECK FOR DTC

(a) Check for DTCs.

Chassis > EMPS > Trouble Codes

Result

Proceed to

DTCs are not output.

A

DTCs are output.

B

A

END

B

REPLACE RACK AND PINION POWER STEERING GEAR ASSEMBLY

READ NEXT:

 Assist Map Number Un-Writing (C1581)

DESCRIPTION This DTC will be stored if the power steering ECU (rack and pinion power steering gear assembly) determines that the assist map is not written in the ECU. DTC No. Detection Item DTC

 Assist Map Number Mismatch (C1582)

DESCRIPTION When an incorrect ECM, skid control ECU (brake actuator assembly) or AVS ECU (Absorber control ECU) (w/ Adaptive Variable Suspension System) is installed after the assist map has been writ

 Assist Map Number Mismatch (C1582)

DESCRIPTION When an incorrect ECM, skid control ECU (brake actuator assembly) or AVS ECU (Absorber control ECU) (w/ Adaptive Variable Suspension System) is installed after the assist map has been writ

SEE MORE:

 Problem Symptoms Table

PROBLEM SYMPTOMS TABLE NOTICE: Depending on the parts that are replaced during vehicle inspection or maintenance, performing initialization, registration or calibration may be needed. Refer to Precaution for Navigation System. Click here When replacing the radio receiver assembly or navigatio

 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