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DTC C1753: ACC/FCM Radar Blockage Detected
 
 
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.
noteThe radar may not function normally if foreign object or dirt (snow or ice) is adhered on the radar or its surrounding area, or the road condition is bad due to a severe weather (heavy rain or snow). In that case, the system will deactivate the ACC and/or FCM as system protection and display an alert message ("ACC or FCM temporarily not available") on the combination meter.
 
 
OPERATION
The ACC-ECU monitors whether the radar or its surrounding area is contaminated or its beam is blocked by foreign material.
 
 
DIAGNOSTIC TROUBLE CODE SET CONDITION
This diagnostic trouble code is set when the abnormality below is detected:
  • If any of the following conditions are satisfied with the cruise control switch or the FCM switch "ON", the system will determine that the radar detection performance is deteriorated.
    • The radar or its surrounding area is contaminated with dirt or foreign material (snow or ice).
    • The system cannot monitor a vehicle-travelling-ahead steadily due to a water splash, etc.
    • The system receives little radar reflection from a distance (traffic is not heavy and free of obstacles, or the obstacles are covered with snow).
 
 
PROBABLE CAUSES
  • The radar or its surrounding area is contaminated by dirt or foreign material, etc.
  • Improperly installed ACC-ECU
  • Malfunction of ACC-ECU

 
 
DIAGNOSIS
STEP 1. Check the radar or its surrounding area for dirt or foreign material.
(1) Wipe off the dirt or foreign material from the ACC-ECU's radar or its surrounding area.
(2)
cautionTo prevent damage to scan tool (M.U.T.-III), always turn the ignition switch to the "LOCK" (OFF) position before connecting or disconnecting scan tool (M.U.T.-III).
Connect scan tool (M.U.T.-III). Refer to "How to connect the Scan Tool (M.U.T.-III) ."
(3) Turn the ignition switch to the "ON" position.
(4) Erase the diagnostic trouble code.
(5) Drive the vehicle for approx. five minutes.
(6) Check if the diagnostic trouble code is set.
(7) Turn the ignition switch to the "LOCK" (OFF) position.
Is diagnostic trouble code No.C1753 set?
Go to Step 2.
This diagnosis is complete. The system has deactivated the ACC or/and FCM temporarily for safety reason. This is not a malfunction.
 
STEP 2. Check whether the ACC-ECU is installed properly.
Check whether the ACC-ECU is installed correctly (Refer to ).
Is the check result normal?
Go to Step 3.
Reinstall the ACC-ECU correctly (Refer to ).
 
STEP 3. Check whether the diagnostic trouble code is set again.
Is diagnostic trouble code No.C1753 set?
Replace the ACC-ECU (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).