[ Model - ECLIPSE CROSS / Year - 2018 ]
2018 / ECLIPSE CROSS / EC - Workshop Manual
54 -CHASSIS ELECTRICAL > 54A-CHASSIS ELECTRICAL > ETACS > DIAGNOSIS CODE PROCEDURES > CODE No.U0121 ABS/ASC-ECU TIMEOUT
Code No.U0121 ABS/ASC CAN timeout
 
 
caution
  • If diagnosis code No. U0121 is set in the ETACS-ECU, always diagnose the CAN bus line.
  • Before replacing the ECU, ensure that the power supply circuit, the earth circuit and the communication circuit are normal.
 
 
DIAGNOSTIC FUNCTION
If the signal from ASC-ECU cannot be received, the ETACS-ECU sets diagnosis code No. U0121.
 
 
JUDGEMENT CRITERIA
After the following statuses continue to be true for 5 seconds, if the communication with the ASC-ECU cannot be established for 2,500 ms or more, the ETACS-ECU determines that a problem has occurred.
  • No abnormality is present to the network.
  • Ignition switch is in the "ON" position.
  • No abnormality is present to the power supply fuse (IOD fuse), or the odometer value is at 80.5 km or more.
  • ETACS-ECU system voltage is at 10-16 V.
 
 
PROBABLE CAUSES
  • Malfunction of ASC-ECU
  • Malfunction of the ETACS-ECU
  • Malfunction of the CAN bus
 
 
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-IIISE CAN bus diagnostics
Use the M.U.T.-IIISE to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 2.
Repair the CAN bus line (Refer to GROUP 54C - Troubleshooting ).
 
STEP 2. M.U.T.-IIISE other system diagnosis code
Check if diagnosis code is set in the ASC-ECU.
Is the diagnosis code set?
Troubleshoot the ASC. Refer to GROUP 35C - Troubleshooting .
Go to Step 3.
 
STEP 3. M.U.T.-IIISE other system diagnosis code
Check if diagnosis code No. U0121 is set in the engine-ECU or AWC-ECU.
Is the diagnosis code set?
Go to Step 4.
Go to Step 5.
 
STEP 4. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set in the ETACS-ECU.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if diagnosis code is set.
Is the diagnosis code set?
Replace the ASC-ECU.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the ASC-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).
 
STEP 5. Check whether the diagnosis code is set again.
Check again if the diagnosis code is set in the ETACS-ECU.
(1) Erase the diagnosis code.
(2) Turn the ignition switch from "LOCK" (OFF) position to "ON" position.
(3) Check if diagnosis code is set.
Is the diagnosis code set?
Replace the ETACS-ECU.
The trouble can be an intermittent malfunction such as a poor connection or open circuit in the CAN bus lines between the ASC-ECU and the ETACS-ECU (GROUP 00 - How to use Troubleshooting/inspection Service Points - How to Cope with Intermittent Malfunction ).