C1394

DTC C1394: INCOMP. learn neutral (SAS)

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.

CAUTION
Whenever the ECU is replaced, ensure that the CAN bus lines are normal.

DTC SET CONDITIONS
This DTC is set if the steering wheel sensor has not been initialized.

TROUBLESHOOTING HINTS (THE MOST LIKELY CAUSES FOR THESE DTCS ARE TO SET ARE:)
^ The CAN bus line is defective.
^ Malfunction of the hydraulic unit (integrated with TCL/ASC-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 line.

CAUTION

To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1) Connect scan tool MB991958 to the data link connector.
2) Turn the ignition switch to the "ON" position.
3) Diagnose the CAN bus line.
4) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is the CAN bus line found to be normal?
YES: Go to Step 2.
NO: Repair the CAN bus line (Refer to Diagnosis How to Diagnose the CAN Bus Line). Then go to Step 2.

STEP 2. Recheck for diagnostic trouble code.

CAUTION

To prevent damage to scan tool MB991958, always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool MB991958.

1) Turn the ignition switch to the "ON" position.
2) Erase the DTC.
3) Turn the ignition switch to the "LOCK" (OFF) position.
4) Turn the ignition switch to the "ON" position.
5) Check if the DTC is set.
6) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC C1394 set?
YES: Initialize the steering wheel sensor. Then go to Step 3.
NO: The procedure is complete.

STEP 3. Recheck for diagnostic trouble code.

Check again if the DTC is set.
1) Turn the ignition switch to the "ON" position.
2) Erase the DTC.
3) Turn the ignition switch to the "LOCK" (OFF) position.
4) Turn the ignition switch to the "ON" position.
5) Check if the DTC is set.
6) Turn the ignition switch to the "LOCK" (OFF) position.
Q: Is DTC C1394 set?
YES: Replace the hydraulic unit (integrated with TCL/ASC-ECU). Then go to Step 4.
NO: The procedure is complete.

STEP 4. Recheck for diagnostic trouble code.