2018 / ECLIPSE CROSS / EC - Workshop Manual
35 -SERVICE BRAKES > 35C-ACTIVE STABILITY CONTROL SYSTEM (ASC) > TROUBLESHOOTING<ASC-ECU><ASC-ECU> > DIAGNOSIS CODE PROCEDURES > CODE NO. C1011, C101C, C1027, C1032 ABNORMALITY IN WHEEL SPEED SENSOR SIGNAL
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 - 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.
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
- Wheel speed sensor signal continuously indicates high value.
PROBABLE CAUSES
Current trouble
- Excessive gap between the wheel speed sensor and the wheel speed detection encoder
- Adhesion of foreign materials on the wheel speed sensor
- Adhesion of foreign materials on the wheel speed detection encoder
- Wheel bearing malfunction
- Malfunction of wheel speed sensor
- Damaged wiring harness and connectors
- External noise interference
- Improper installation of the wheel speed sensor
- Deformation of the wheel speed detection encoder
- ASC-ECU malfunction
- Disturbance of magnetisation pattern for wheel speed detection encoder
- The number of poles on the Magnetic encoder for wheel speed detection (N-pole and S-pole) is changed
Past trouble
- When diagnosis code No.C100A, C1015, C1020 or C102B is also set, 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 Use Troubleshooting/How to Treat Past Trouble
). - When diagnosis code No.C100A, C1015, C1020 or C102B is not set, the following conditions may be present:
- Some wheels slip
- Unstable vehicle attitude
- External noise interference
- Vehicle ran with the parking brake applied
DIAGNOSIS PROCEDURE
STEP 1. M.U.T.-IIISE CAN bus diagnosis
STEP 2. Diagnosis code recheck after resetting CAN bus lines
Is diagnosis code No.C1011, C101C, C1027 or C1032 set?
Go to Step 3.
This diagnosis is complete.
STEP 3. M.U.T.-IIISE diagnosis code
STEP 4. Check the wiring harness between the ASC-ECU connector terminal and the wheel speed sensor connector terminal
Code No.C1011 is set
- Check of short to power supply, short to earth, and open circuit in FL+, FL- line between ASC-ECU connector and front wheel speed sensor (LH) connector.
Code No.C101C is set
- Check of short to power supply, short to earth, and open circuit in FR+, FR- line between ASC-ECU connector and front wheel speed sensor (RH) connector.
Code No.C1027 is set
- Check of short to power supply, short to earth, and open circuit in RL+, RL- line between ASC-ECU connector and rear wheel speed sensor (LH) connector.
Code No.C1032 is set
- Check of short to power supply, short to earth, and open circuit in RR+, RR- line between ASC-ECU connector and rear wheel speed sensor (RH) connector.
Is the check result normal?
Go to Step 5.
Repair the connector(s) or wiring harness.
STEP 5. Check for wheel speed sensor installation
STEP 6. Check for wheel speed sensor output current
STEP 7. Check for wheel bearing looseness
STEP 8. Check of wheel speed detection encoder
STEP 9. Check whether the diagnosis code is set again.
STEP 10. Check whether the diagnosis code is set again.
(1) Erase the diagnosis code.
(2) Drive the vehicle at 20 km/h or higher.| note | The ABS warning lamp does not turn OFF in some cases unless the vehicle runs at 20 km/h or higher. |
Is diagnosis code No.C1011, C101C, C1027 or C1032 set?
Replace the hydraulic unit (integrated with ASC-ECU) (Refer to
).
This diagnosis is complete.