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Code No. C1014 FL wheel speed SNS performance
Code No. C101F FR wheel speed SNS performance
Code No. C102A RL wheel speed SNS performance
Code No. C1035 RR wheel speed SNS performance
 
 
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, Troubleshooting ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
  • When the hydraulic unit assembly (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 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.
 
 
DIAGNOSTIC TROUBLE CODE SET CONDITIONS
ASC-ECU monitors the signals from each wheel speed sensor while the vehicle is being driven. If any fault below is found in these sensor signals, ASC-ECU will set the relevant diagnostic trouble code.
  • Irregular change in the wheel speed sensor signal
 
 
PROBABLE CAUSES
Current trouble
  • Malfunction of the wheel speed sensor
  • Excessive gap between the wheel speed sensor and the rotor (for wheel speed detection)
  • Malfunction of the wheel speed sensor installation
  • Malfunction of the wheel bearing
  • Malfunction of the front axle hub assembly
  • Malfunction of the rear axle hub assembly
  • Deformation of the wheel speed detection magnetic encoder
  • Damaged wiring harness and connectors
  • Malfunction of the hydraulic unit assembly (integrated with ASC-ECU)
Past trouble
  • Carry out diagnosis with particular emphasis on wiring harness and connector failures between ASC-ECU and the wheel speed sensor. For diagnosis procedures, refer to How to treat past trouble (GROUP 00, How to Cope with Intermittent Malfunctions ).
 
 
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. C1014, C101F, C102A or C1035 set?
Go to Step 3.
The procedure is complete.
 
STEP 3. M.U.T.-III data list
Check the following data list (Refer to ).
  • (When code No. C1014 is set) Item No.01: FL wheel speed sensor
  • (When code No. C101F is set) Item No.02: FR wheel speed sensor
  • (When code No. C102A is set) Item No.03: RL wheel speed sensor
  • (When code No. C1035 is set) Item No.04: RR wheel speed sensor
Is the check result normal?
Go to Step 9.
Go to Step 4.
 
STEP 4. Harness and connector check
(1) Check the wheel speed sensor (FL, FR, RL or RR).
(2) Check the ASC-ECU connector.
(3) Check the wiring harness and connector between the ASC-ECU connector and the wheel speed sensor (FL, FR, RL or RR).
Is the check result normal?
Go to Step 5.
Repair the defective connector or the wiring harness. Then go to Step 10.
 
STEP 5. Check whether the wheel speed sensors are installed properly
Check whether the wheel speed sensor relevant to code No. is installed correctly (sensor dislocation, loose mounting bolt, etc.).
 
Diagnostic trouble code No. Relevant sensor
C1014Front left
C101FFront right
C102ARear left
C1035Rear right
Is the check result normal?
Go to Step 6.
Repair the wheel speed sensor. Then go to Step 10.
 
STEP 6. Check for wheel speed sensor as a single unit
Refer to .
Is the check result normal?
Go to Step 7.
Replace the wheel speed sensor (Refer to ). Then go to Step 10.
 
STEP 7. Check of wheel speed detection magnetic encoder are installed properly
Check whether the wheel speed detection magnetic encoder relevant to code No. is installed correctly (adhesion of foreign materials, deformation, etc.).
 
Diagnostic trouble code No. Relevant encoder
C1014Front left
C101FFront right
C102ARear left
C1035Rear right
Is the check result normal?
Go to Step 8.
<when the relevant wheel is front> : 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. If deformation is found, replace the wheel bearing (Refer to GROUP 26, Front Axle Hub Assembly ). Then go to Step 10.
<when the relevant wheel is rear> : 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. If deformation is found, replace the pulse rotor (Refer to GROUP 27, Rear Axle Hub Assembly ). Then go to Step 10.
 
STEP 8. 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 indicated by the code No. for looseness.
 
Diagnostic trouble code No. Relevant bearing
C1014Front left
C101FFront right
C102ARear left
C1035Rear right
Is the check result normal?
Go to Step 9.
Replace the wheel bearing. Then go to Step 10.
 
STEP 9. Check whether the diagnostic trouble code is set again.
Check again if the diagnostic trouble code is set.
(1) Erase the diagnostic trouble code.
(2) Ignition switch: "LOCK" (OFF) position to "ON"
(3) Drive the vehicle at 15 km/h or more.
noteThe ABS warning light does not turn OFF in some cases unless the vehicle runs at 15 km/h or higher.
Is diagnostic trouble code No. C1014, C101F, C102A or C1035 set?
Replace the hydraulic unit assembly (integrated with ASC-ECU) (Refer to ). Then go to Step 10.
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).
 
STEP 10. Check whether the diagnostic trouble code is set again.
Check again if the diagnostic trouble code is set.
(1) Erase the diagnostic trouble code.
(2) Ignition switch: "LOCK" (OFF) position to "ON"
(3) Drive the vehicle at 15 km/h or more.
noteThe ABS warning light does not turn OFF in some cases unless the vehicle runs at 15 km/h or higher.
Is diagnostic trouble code No. C1014, C101F, C102A or C1035 set?
Return to Step 3.
This diagnosis is complete.