Code No. C1011: FL wheel speed sensor signal
Code No. C101C: FR wheel speed sensor signal
Code No. C1027: RL wheel speed sensor signal
Code No. C1032: RR wheel speed sensor signal
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 - Troubleshooting
).
- Whenever ECU is replaced, ensure that the CAN bus lines are normal.
- When the hydraulic unit assembly (integrated with ASTC-ECU) is replaced, always carry out the calibration of the steering wheel sensor and the G sensor (Refer to
).
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OPERATION
- A toothed rotor (for wheel speed detection) generates a voltage pulse as it moves across the pickup field of each wheel speed sensor.
- The wheel speed sensor transmit the frequency of the pulses to the ASTC-ECU.
DIAGNOSIS CODE SET CONDITIONS
ASTC-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, ASTC-ECU will set the relevant diagnosis code.
- Irregular change in the wheel speed sensor signal
PROBABLE CAUSES
Current trouble
- External noise interference
- Damaged wiring harness and connectors
- Malfunction of wheel speed sensor
- Adhesion of foreign materials on the wheel speed sensor
- Adhesion of foreign materials on the rotor (for wheel speed detection)
- Improper installation of the wheel speed sensor
- Malfunction of the hydraulic unit assembly (integrated with ASTC-ECU)
- Deformation of the rotor (for wheel speed detection)
- The number of poles on the rotor (for wheel speed detection) is changed
Past trouble
- Carry out diagnosis with particular emphasis on wiring harness and connector failures between ASTC-ECU and the wheel speed sensor. For diagnosis procedures, refer to How to treat past trouble (GROUP 00 - How to Cope with Intermittent Malfunctions
).
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STEP 1. M.U.T.-III CAN bus diagnosis
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Use 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. C101C, C1011, C1032 or C1027 set?
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Go to Step 3.
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The procedure 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. C1011 is set) Item No. 01: FL wheel speed sensor
- (When code No. C101C is set) Item No. 02: FR wheel speed sensor
- (When code No. C1027 is set) Item No. 03: RL wheel speed sensor
- (When code No. C1032 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 7.
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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 ASTC-ECU connector.
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(3)Check the wiring harness and connector between the ASTC-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 8.
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STEP 5. Rotor (for wheel speed detection) check
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Check the rotor (for wheel speed detection) (Refer to ).
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Q.
Is the check result normal?
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Go to Step 6.
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Replace the rotor (for wheel speed detection). Then go to Step 8.
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STEP 6. Check for wheel speed sensor as a single unit
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Check the wheel speed sensor (Refer to ).
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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 (Refer to ). Then go to Step 8.
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STEP 7. 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 60 km/h or more.
note |
The ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 60 km/h or higher.
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Q.
Is diagnosis code No. C101C, C1011, C1032 or C1027 set?
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Replace the hydraulic unit assembly (integrated with ASTC-ECU) (Refer to ).
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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 8. 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 60 km/h or more.
note |
The ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 60 km/h or higher.
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Q.
Is diagnosis code No. C101C, C1011, C1032 or C1027 set?
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Replace the hydraulic unit assembly (integrated with ASTC-ECU) (Refer to ).
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This diagnosis is complete.
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