Lexus ES: 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. |
|
CAUTION / NOTICE / HINT
NOTICE:
After replacing the skid control ECU (brake actuator assembly), perform acceleration sensor zero point calibration and store system information memorization.
Click here .gif)
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 |
|
| 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 |
|
| 3. | CONFIRM SYSTEM INFORMATION STORAGE |
(a) Check that Store System Information (acceleration sensor zero point calibration and store 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 store system information memorization) is performed.
| OK | | REPLACE BRAKE ACTUATOR ASSEMBLY |
| NG | | PERFORM ACCELERATION SENSOR ZERO POINT CALIBRATION AND STORE SYSTEM INFORMATION MEMORIZATION |
READ NEXT:
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 a
Wheel Speed Sensor Signal Compare Failure (C124E62)
DESCRIPTION The skid control ECU (brake actuator assembly) measures the speed of each wheel by receiving signals from each speed sensor. These signals are used for recognizing that all four wheels are
Brake System Control Module "A" System Voltage System Voltage Low (C137BA2)
DESCRIPTION If a malfunction is detected in the power supply circuit, the skid control ECU (brake actuator assembly) stores this DTC and the fail-safe function prohibits ABS operation. This DTC is sto
SEE MORE:
Maintenance and care
Maintenance and care
Cleaning and protecting the vehicle
exterior
Perform cleaning in a manner
appropriate to each component
and its material.
Cleaning instructions
Working from top to bottom, liberally
apply water to the vehicle body,
wheel wells and underside of the
vehicle to remo
Terminals Of Ecu
TERMINALS OF ECU CHECK LUGGAGE CLOSER MOTOR ASSEMBLY (a) Disconnect the R7 luggage closer motor assembly connector. (b) Measure the voltage and resistance according to the value(s) in the table below. Terminal No. (Symbol) Wiring Color Terminal Description Condition Specified Condition
