Toyota Corolla Cross Owners & Service Manuals

Toyota Corolla Cross: ECM Communication (C124A00)

Toyota Corolla Cross (2022-2025) Service Manual / Brake / Brake Control / Dynamic Control Systems / Electronically Controlled Brake System (for Gasoline Model) / ECM Communication (C124A00)

DESCRIPTION

If the vehicle information stored by the skid control ECU (brake actuator assembly) does not match that sent from the ECM or a new skid control ECU (brake actuator assembly) is installed and the vehicle information has not been stored, this DTC is stored.

DTC No.

Detection Item

DTC Detection Condition

Trouble Area

C124A00

ECM Communication

Engine, drive source and destination information sent from the ECM does not match the information of the skid control ECU or there is no information in memory.
  • ECM
  • Skid control ECU (brake actuator assembly)

PROCEDURE

1.

CHECK PART NUMBER (ECM)

(a) Check that the proper ECM is installed.

OK:

Proper ECM is installed.

(b) Check if the ECM was replaced before the DTC was stored.

OK:

ECM was not replaced.

Result

Proceed to

OK

A

NG (A proper ECM is not installed and/or the ECM was replaced.)

B
B

REPLACE ECM

A

2.

CHECK PART NUMBER (BRAKE ACTUATOR ASSEMBLY)

(a) Check that a proper skid control ECU (brake actuator assembly) is installed.

OK:

Proper skid control ECU (brake actuator assembly) is installed.

(b) Check if the skid control ECU (brake actuator assembly) had been replaced before the DTC was stored.

OK:

Skid control ECU (brake actuator assembly) had not been replaced.

Result

Proceed to

OK

A

NG (The skid control ECU (brake actuator assembly) had been replaced.)

B

NG (A proper skid control ECU (brake actuator assembly) is not installed.)

C
A

REPLACE BRAKE ACTUATOR ASSEMBLY

C

REPLACE BRAKE ACTUATOR ASSEMBLY

B

3.

CONFIRM SYSTEM INFORMATION STORAGE

(a) Check that Store System Information (acceleration sensor zero point calibration and system information memorization) has been performed.

OK:

Store System Information has been performed.

HINT:

After installing a new skid control ECU (brake actuator assembly), DTCs C051D54 and C124A00 will be stored until system variant learning (acceleration sensor zero point calibration and system information memorization) is performed.

OK

REPLACE BRAKE ACTUATOR ASSEMBLY

NG

PERFORM ACCELERATION SENSOR ZERO POINT CALIBRATION AND SYSTEM INFORMATION MEMORIZATION

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