Code No. C1014:
FL wheel speed sensor performance
Code No. C101F: FR wheel speed sensor performance
Code
No. C102A: RL wheel speed sensor performance
Code No. C1035: RR wheel speed sensor
performance
| caution |
- If there is any
problem in the CAN bus lines, an incorrect diagnosis code may be set. Prior to this diagnosis,
diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table
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- 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 G and yaw rate sensor and the steering wheel sensor (Refer to and ).
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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.
DIAGNOSIS 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 diagnosis 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 wheel speed detection magnetic
encoder
- 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 wheel speed sensor. For diagnosis procedures, refer to
How to treat past trouble. (GROUP 00 - How to Use Troubleshooting/Inspection
Service Points).
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STEP 1. M.U.T.-III CAN bus diagnosis.
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Use the M.U.T.-III to diagnose the CAN bus lines.
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Q.
Is the check result normal?
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 Go to Step 3.
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 Repair the CAN bus line. (Refer to GROUP 54C - Troubleshooting ).
On completion, go to Step 2.
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STEP 2. Diagnosis code recheck after resetting CAN bus lines.
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Q.
Is diagnosis code No. C1014, C101F, C102A or C1035 set?
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Go to Step 3.
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This diagnosis is complete.
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STEP 3. M.U.T.-III data list.
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Check the following data list (Refer to ).
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- (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
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Q.
Is the check result normal?
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Go to Step 9.
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Go to Step 4.
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STEP 4. Harness and connector check.
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(1)Check the wheel speed sensor (FL, FR, RL or RR).
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(2)Check the ASC-ECU connector.
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(3)Check the wiring harness and connector between the ASC-ECU connector and the wheel
speed sensor (FL, FR, RL or RR).
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Q.
Is the check result normal?
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Go to Step 5.
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Repair the defective connector or the wiring harness. Then go to Step 10.
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STEP 5. Check whether the wheel speed sensors are installed properly.
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Check whether the wheel speed sensor relevant to code No. is installed correctly (sensor
dislocation, loose mounting bolt, etc.).
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Diagnosis code No.
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Relevant sensor
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C1014
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Front left
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C101F
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Front right
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C102A
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Rear left
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C1035
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Rear right
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Q.
Is the check result normal?
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Go to Step 6.
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Install the wheel speed sensor properly. Then go to Step 10.
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STEP 6. Check for wheel speed sensor as a single unit.
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Q.
Is the check result normal?
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Go to Step 7.
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Replace the wheel speed sensor. Then go to Step 10.
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STEP 7. Check of wheel speed detection magnetic encoder are installed
properly.
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Check whether the wheel speed detection magnetic encoder relevant to code No. is installed
correctly (adhesion of foreign materials, deformation, etc.).
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Diagnosis code No.
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Relevant encoder
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C1014
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Front left
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C101F
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Front right
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C102A
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Rear left
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C1035
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Rear right
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Q.
Is the check result normal?
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Go to Step 8.
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NO <when the relevant wheel is front> : Remove the foreign materials and clean the encoder so as not to disturb the magnetisation
pattern on it while taking care of the magnet, magnetic substance, and magnetic attraction.
If deformation is found, replace the wheel bearing. Then go to Step 10.
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NO <when the relevant wheel is rear> : Remove the foreign materials and clean the encoder so as not to disturb the magnetisation
pattern on it while taking care of the magnet, magnetic substance, and magnetic attraction.
If deformation is found, replace the pulse rotor. Then go to Step 10.
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STEP 8. Check for wheel bearing looseness.
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| note |
Loose 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.
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Diagnosis code No.
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Relevant bearing
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C1014
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Front left
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C101F
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Front right
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C102A
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Rear left
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C1035
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Rear right
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Q.
Is the check result normal?
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Go to Step 9.
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Replace the wheel bearing. Then go to Step 10.
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STEP 9. Check whether the diagnosis code is set again.
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(1)Turn the ignition switch to the "ON" position.
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(2)Turn the ignition switch to the "LOCK" (OFF) position.
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(3)Drive the vehicle at 15 km/h or more.
| note |
The ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 15 km/h or
higher.
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Q.
Is diagnosis code No. C1014, C101F, C102A or C1035 set?
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Replace the hydraulic unit assembly (integrated with ASC-ECU) (Refer to ). Then
go to Step 10.
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The trouble can be an intermittent malfunction (Refer to GROUP 00 - How
to Cope with Intermittent Malfunction).
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STEP 10. Check whether the diagnosis code is set again.
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(1)Turn the ignition switch to the "ON" position.
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(2)Turn the ignition switch to the "LOCK" (OFF) position.
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(3)Drive the vehicle at 15 km/h or more.
| note |
The ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 15 km/h or
higher.
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Q.
Is diagnosis code No. C1014, C101F, C102A or C1035 set?
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Return to Step 3.
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This diagnosis is complete.
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