U0431
Code No.U0431: ETACS Data Malfunction
CAUTION:
- If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
- Whenever the ECU is replaced, ensure that the CAN bus lines are normal.
OPERATION
AWC-ECU communicates with the ETACS-ECU via the CAN bus lines.
DIAGNOSTIC TROUBLE CODE SET CONDITIONS
The code is set when abnormality is detected in the signal received from ETACS-ECU.
PROBABLE CAUSES
- Malfunction of the CAN bus line
- Malfunction of ETACS-ECU power supply circuit system
- ETACS-ECU malfunction
- Malfunction of AWC-ECU
- Coding not implemented
DIAGNOSTIC PROCEDURE
STEP 1. M.U.T.-III CAN bus diagnostics.
Use scan tool to perform the CAN bus diagnosis.
Q. Is the check result normal?
YES Go to Step 2.
NO Repair the CAN bus lines. CAN Bus Diagnostics Chart).
STEP 2. M.U.T.-III diagnostic trouble code.
Check if the AWC diagnostic trouble code No.U1415 is set. (Refer to Automatic Transmission).
Q. Is the diagnostic trouble code set?
YES Perform the relevant troubleshooting.
NO Go to Step 3.
STEP 3. M.U.T.-III diagnostic trouble code.
Check the ETACS diagnostic trouble code. Electronic Time and Alarm Control System (ETACS)).
Q. Is the diagnostic trouble code set?
YES Perform the relevant troubleshooting.
NO Go to Step 4.
STEP 4. M.U.T.-III data list.
Check the ETACS data list below. Data List Reference Table).
- Item No.252: Ambient temperature sensor
- Item No.254: IG voltage
Q. Is the check result normal?
YES Go to Step 5.
NO Replace the ETACS-ECU. Electronic Time and Alarm Control System (ETACS)-ECU Removal and Installation). Then go to Step 5.
STEP 5. Check whether the diagnostic trouble code is reset.
Q. Is diagnostic trouble code No.U0431 set?
YES Replace the AWC-ECU. (Refer to AWC-ECU Removal and Installation). Then go to Step 6.
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions).
STEP 6. Check whether the diagnostic trouble code is reset.
Q. Is diagnostic trouble code No.U0431 set?
YES Return to Step 1.
NO This diagnosis is complete.