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DTC C1041 FL Wheel Speed Tone Performance
DTC C1042 FR Wheel Speed Tone Performance
DTC C1043 RL Wheel Speed Tone Performance
DTC C1044 RR Wheel Speed Tone Performance
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
 
 
OPERATION
  • The wheel speed sensor is a kind of a pulse generator. It consists of encoders (a plate on which north and south pole sides of the magnets are arranged alternately) for detecting the wheel speed which rotates at the same speed of the wheels and wheel speed sensors. This sensor outputs frequency pulse signals in proportion to the wheel speed.
  • The pulse signals, which the wheel speed sensor creates, are sent to ASC-ECU. ASC-ECU uses the frequency of the pulse signals to determine the wheel speed.
 
 
 
DTC SET CONDITIONS
ASC-ECU monitors the signals from each wheel speed sensor while the vehicle is being driven. If any periodical drop is found in these sensor signals, ASC-ECU will set the relevant DTC.
 
 
 
PROBABLE CAUSES
  • Wheel bearing malfunction
  • Deformation of the wheel speed detection encoder
  • Adhesion of foreign materials on the wheel speed detection encoder
  • ASC-ECU malfunction
  • The number of poles on the Magnetic encoder for wheel speed detection (N-pole and S-pole) is changed
 
 
 
 
DIAGNOSIS
STEP 1. Check for wheel bearing looseness
noteLoose wheel bearing may increase the gap between the wheel speed sensor and the wheel speed detection magnet encoder. Check the wheel bearing for looseness. [Refer to GROUP 26 - Wheel Bearing Axial Play Check (Front), GROUP 27A - Wheel Bearing Axial Play Check (Rear) <FWD>, GROUP 27B - Wheel Bearing Axial Play Check (Rear) <AWD>].
Is the check result normal?
Go to Step 2.
Replace the wheel bearing (Front) or rear wheel hub assembly (Rear) [Refer to GROUP 26 - Front Axle Hub Assembly (Front), GROUP 27A - Rear Axle Hub Assembly (Rear) <FWD>, GROUP 27B - Rear Axle Hub Assembly (Rear) <AWD>].
 
STEP 2. Check of wheel speed detection encoder
Check the encoder for adhesion of foreign materials or deformation.
Is the check result normal?
Go to Step 3.
: Remove the foreign materials and clean the encoder so as not to disturb the magnetization pattern on it while taking care of the magnet, magnetic substance, and magnetic attraction.
: Replace the wheel bearing (Front) or rear wheel hub assembly (Rear) [Refer to GROUP 26 - Front Axle Hub Assembly (Front), GROUP 27A - Rear Axle Hub Assembly (Rear) <FWD>, GROUP 27B - Rear Axle Hub Assembly (Rear) <AWD>].
 
STEP 3. Check whether the DTC is set again.
(1) Erase the DTC.
(2) Turn the ignition switch to the "LOCK" (OFF) position.
(3) Turn the ignition switch to the "ON" position.
(4) Drive the vehicle at 20 km/h (12 mph) or higher.
noteThe ABS warning light does not turn OFF in some cases unless the vehicle runs at 20 km/h (12 mph) or higher.
Is DTC C1041, C1042, C1043 or C1044 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to ).
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/How to Cope with Intermittent Malfunctions ).