Wireless Control Module (WCM)

DTC U1412: Implausible Vehicle Speed Signal Received

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 (Refer to Trouble code diagnosis). Can Bus Diagnostics Table

DTC SET CONDITION
WCM receives the wheel speed information from ASC-ECU via the CAN-bus line. If WCM cannot receive the information about the wheel speed sensor from ASC-ECU, this code is set.

TROUBLESHOOTING HINTS
The most likely causes for this DTC to set are:
- Damaged wiring harness and connector
- Malfunction of ASC-ECU
- Malfunction of WCM
- Malfunction of ETACS-ECU

DIAGNOSIS

Required Special Tools:
- MB991958 Scan Tool (M.U.T.-III Sub Assembly)
- MB991824: Vehicle Communication Interface (V.C.I.)
- MB991827 M.U.T.-III USB Cable
- MB991910 M.U.T.-III Main Harness A

STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.

Use scan tool to diagnose the CAN bus lines.

Q: Is the check result normal?

YES : Go to Step 3.

NO : Repair the CAN bus lines. On completion, go to Step 2.

STEP 2. Diagnostic trouble code recheck after resetting CAN bus lines

1. Turn the ignition switch to the "LOCK" (OFF) position.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC U1412 set?

YES : Go to Step 3.

NO : The procedure is complete.

STEP 3. Vehicle speed check by combination meter

During the vehicle driving, check that the correct vehicle speed is displayed on the combination meter.

Q: Is the check result normal?

YES : Replace the WCM and register ID codes. Then go to Step 6.

NO : Go to Step 4.

STEP 4. Check for other diagnostic trouble code.

Check if the diagnostic trouble code is set from ASC-ECU (Refer to diagnostic trouble code chart). Diagnostic Trouble Code Descriptions

Q: Is the check result normal?

YES : Go to Step 5.

NO : Carry out the relevant troubleshooting. (Refer to diagnostic trouble code chart). Diagnostic Trouble Code Descriptions Then go to Step 5.

STEP 5. Check for other diagnostic trouble code.

Check if the diagnostic trouble code is set from ETACS-ECU (Refer to ETACS - diagnostic trouble code chart). Diagnostic Trouble Code Descriptions

Q: Is the check result normal?

YES : Diagnose the combination meter. (Refer to Combination meter diagnostic trouble code chart) Diagnostic Trouble Code Descriptions Go to Step 6.

NO : Carry out the relevant troubleshooting. (Refer to ETACS - diagnostic trouble code chart). Diagnostic Trouble Code Descriptions Then go to Step 6.

STEP 6. Recheck for diagnostic trouble code.

1. Turn the ignition switch to the "LOCK" (OFF) position.
2. Turn the ignition switch to the "ON" position.
3. Check if the DTC is set.
4. Turn the ignition switch to the "LOCK" (OFF) position.

Q: Is the DTC U1412 set?

YES : Start over at Step 1.

NO : The procedure is complete.