Mitsubishi Motors Service Manual

2018 / ECLIPSE CROSS / EC - Workshop Manual

23 -AUTOMATIC TRANSMISSION > 23A-CVT > TROUBLESHOOTING<CVT><CVT> > DIAGNOSIS CODE PROCEDURES > CODE NO. U0121 CAN TIMEOUT ERROR (ABS)

Code No. U0121: CAN time-out error (ABS/ASC)

caution

If there is any problem in the CAN bus lines, an incorrect diagnosis 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.

DIAGNOSTIC FUNCTION

The CVT-ECU determines that the system is defective if the ECU can receive no CAN communication information from the ASC-ECU.

JUDGEMENT CRITERIA

No information is received from the ASC-ECU for 0.5 seconds.

PROBABLE CAUSES

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-IIISE CAN bus diagnostics.

Use M.U.T.-IIISE to perform the CAN bus diagnosis.

Is the check result normal?

Go to Step 2.

Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting

STEP 2. Check for diagnosis codes of other systems.

Check whether an ASC "time-out" related diagnosis code is set in other ECUs (Refer to GROUP 54C - CAN-Related Diagnosis Code Table

Is the diagnosis code set?

Go to Step 3.

Go to Step 4.

STEP 3. Check whether the diagnosis code is set again.

Check again if the diagnosis code is set.

(1) Erase the diagnosis code.

(2) Turn the ignition switch to the LOCK (OFF) position.

(3) Turn the ignition switch to the ON position.

(4) Check if the diagnosis code is set.

Is diagnosis code No. U0121 set?

Replace the hydraulic unit (ASC-ECU) (Refer to GROUP 35C - Hydraulic Unit

Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction

STEP 4. Check whether the diagnosis code is set again.