S-AWC (Super All Wheel Control)

DTC U0401: Engine 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 engine control module via the CAN bus lines.

DTC SET CONDITIONS

The code is set when abnormality is detected in the signal received from the engine control module.

PROBABLE CAUSES

- The CAN bus line is defective.
- Engine malfunction
- 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. CAN Bus Diagnostics Chart.)
STEP 2. Scan tool diagnostic trouble code

Check the engine diagnostic trouble code. Multiport Fuel Injection (MFI).)

Q. Is the DTC set?

YES Perform the relevant troubleshooting.
NO Go to Step 3.
STEP 3. Scan tool service data

Check the following service data. (Refer to service data reference table Data List Reference Table.)

- Item No.15: Engine speed
- Item No. 16: Engine torque (Driver request value)

Q. Is the check result normal?

YES Intermittent malfunction. How to Cope With Intermittent Malfunctions.)
NO Go to Step 4.
STEP 4. Check whether the DTC is reset.

Q. Is DTC No. U0401 set?

YES Replace the AWC-ECU. (Refer to Active Center Differential (ACD).) Then go to Step 5.
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions.)
STEP 5. Check whether the DTC is reset.

Q. Is DTC No. U0401 set?

YES Return to Step 1.
NO This diagnosis is complete.