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Code No. U1104 SAS CAN timeout/Not equipped
 
 
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 (Refer to GROUP 54C, CAN Bus Diagnostics Table ).
  • If diagnostic trouble code U1104 is set 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 set. In this case, the set diagnostic trouble code is not highly reliable.
  • When the steering wheel sensor is replaced, always carry out calibration to make ASC-ECU learn the neutral point (Refer to ).
  • 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 steering wheel sensor via the CAN bus lines.
 
 
DIAGNOSTIC TROUBLE CODE SET CONDITIONS
If the ACS-ECU cannot receive any signal from the steering wheel sensor for a predetermined period, this diagnostic trouble code will be set.
 
 
PROBABLE CAUSES
  • The CAN bus line is defective.
  • Malfunction of the steering wheel sensor
  • Malfunction of the hydraulic unit assembly (integrated with ASC-ECU)
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-III), diagnose the CAN bus lines.
Use scan tool (M.U.T.-III) 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. U1104 set?
Go to Step 3.
This diagnosis is complete.
 
STEP 3. Check other diagnostic trouble codes.
Check if diagnostic trouble code(s) other than U1104 is set.
Is the diagnostic trouble code set?
Perform troubleshooting for the relevant diagnostic trouble code. Then go to Step 6 .
Go to Step 4.
 
STEP 4. Use scan tool (M.U.T.-III) to confirm a diagnostic trouble code of other systems.
Check whether a steering wheel sensor "time-out" related diagnostic trouble code is set in other ECUs.
Is the diagnostic trouble code set?
Replace the steering wheel sensor (Refer to ). Then go to Step 6.
Go to Step 5.
 
STEP 5. Check whether the diagnostic trouble code is set again.
Check again if the diagnostic trouble code is set.
(1) Erase the set diagnostic trouble code.
(2) Ignition switch: "LOCK" (OFF)
(3) Ignition switch: "ON"
Is diagnostic trouble code No. U1104 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ). Then go to Step 6.
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
 
STEP 6. Check whether the diagnostic trouble code is set again.
Check again if the diagnostic trouble code is set.
(1) Erase the set diagnostic trouble code.
(2) Ignition switch: "LOCK" (OFF)
(3) Ignition switch: "ON"
Is diagnostic trouble code No. U1104 set?
Return to Step 3.
This diagnosis is complete.