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Code No. U1101 T/M CAN timeout
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be stored. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • If diagnostic trouble code U1101 is stored in ASC-ECU, always diagnose the CAN bus line. If there is any fault in the CAN bus lines, an incorrect diagnostic trouble code may be stored. In this case, the stored diagnostic trouble code is not highly reliable.
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
  • When the hydraulic unit (integrated with ASC-ECU) is replaced, always carry out the calibration of the steering wheel sensor and the G and yaw rate sensor (Refer to and ).
 
 
OPERATION
The ASC-ECU communicates with the CVT-ECU via the CAN bus lines.
 
 
DIAGNOSTIC TROUBLE CODE SET CONDITIONS
The ASC-ECU receives the CVT control-related signals from the CVT-ECU via the CAN bus lines. When these signals cannot be received, the ECU stores this diagnostic trouble code.
 
 
PROBABLE CAUSES
  • Malfunction of ETACS-ECU
  • The ASC-ECU, which was used on another vehicle, is installed on this vehicle.
  • The ETACS-ECU, which was used on another vehicle, is installed on this vehicle.
  • The CAN bus line is defective.
  • The CVT-ECU is defective.
  • Malfunction of ASC-ECU
 
 
DIAGNOSIS
STEP 1. Using scan tool MB991958, diagnose the CAN bus lines.
Use the scan tool MB991958 to diagnose the CAN bus lines.
Is the check result normal?
Go to Step 3.
Repair the CAN bus line. (Refer to GROUP 54C - Troubleshooting .) On completion, go to Step 2.
 
STEP 2. Diagnostic trouble code recheck after resetting CAN bus lines
Is diagnostic trouble code No. U1101 stored?
Go to Step 3.
This diagnosis is complete.
 
STEP 3. Use scan tool MB991958 to confirm a diagnostic trouble code of other systems.
Check if the diagnostic trouble code is stored in the CVT-ECU (Refer to GROUP 23A - Diagnostic Trouble Code Chart ).
Is the diagnostic trouble code stored?
Follow the relevant diagnostic trouble code procedure. Then go to Step 5.
Go to Step 4.
 
STEP 4. Use scan tool MB991958 to confirm a diagnostic trouble code of other systems.
Check whether an transmission "time-out" related diagnostic trouble code is stored in other ECUs.
Is the diagnostic trouble code stored?
Replace the CVT-ECU (Refer to GROUP 23A - CVT-ECU ). Then go to Step 7.
Go to Step 5.
 
STEP 5. ETACS-ECU coding data check
Use scan tool MB991958, check if any abnormality is present to the coding data which are stored in the ETACS-ECU. (Refer to GROUP 00 - Coding Reference Table .)
Is the check result normal?
Go to Step 6.
Replace ETACS-ECU. (Refer to GROUP 54A - ETACS-ECU .) Then go to Step 7.
 
STEP 6. Check part number of ASC-ECU
Check the part number of ASC-ECU.
Is the check result normal?
Go to Step 7.
Replace the hydraulic unit (integrated with ASC-ECU). (Refer to .) Then go to Step 7.
 
STEP 7. Check whether the diagnostic trouble code is stored again.
Check again if the diagnostic trouble code is stored.
(1) Erase the stored diagnostic trouble code.
(2) Ignition switch: "LOCK" (OFF)
(3) Ignition switch: "ON"
Is diagnostic trouble code No. U1101 stored?
Replace the hydraulic unit (integrated with ASC-ECU). (Refer to .)
The trouble can be an intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).