U1427

DTC U1427: Wheel Speed Sensor Data Error

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 ASC-ECU via the CAN bus lines.

DTC SET CONDITIONS
The code is set when abnormality is detected in the signal received from the wheel speed sensor.

PROBABLE CAUSES
^ The CAN bus line is defective.
^ Malfunction of the CAN bus line (local)
^ Malfunction of ASC-ECU
^ Malfunction of wheel speed sensor
^ Malfunction of AWC-ECU

DIAGNOSTIC PROCEDURE

STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?
YES: Go to Step 2.
NO: Repair the CAN bus lines.

STEP 2. Scan tool diagnostic trouble code
Check if the AWC diagnostic trouble code No. U1003 is set.(Diagnostic Trouble Code Descriptions)
Q: Is the DTC set?
YES: Perform the relevant troubleshooting.
NO: Go to Step 3.

STEP 3. Scan tool diagnostic trouble code
Check the ASC diagnostic trouble code. Diagnostic Trouble Code Descriptions
Q: Is the DTC set?
YES: Perform the relevant troubleshooting.
NO: Go to Step 4.

STEP 4. Scan tool service data
Check the service data below. (Data List Reference Table)
^ Item No.22: FL wheel speed sensor [FL]
^ Item No.23: FL wheel speed sensor [FR]
^ Item No.24: FL wheel speed sensor [RL]
^ Item No.25: FL wheel speed sensor [RR]
Q: Is the check result normal?
YES: Intermittent malfunction.
NO: Go to Step 5.

STEP 5. Check whether the DTC is reset.
Q: Is DTC No. U1427 set?
YES: Replace the AWC-ECU. Then go to Step 6.
NO: Intermittent malfunction.

STEP 6. Check whether the DTC is reset.
Q: Is DTC No. U1415 set?
YES: Return to Step 1.
NO: This diagnosis is complete.