Code No. C1049 RR wheel speed sensor control phase time exceeded


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, Trouble code diagnosis ).

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
This diagnosis code is set if any malfunction below is found:

  • When the brake fluid pressure is decreased for a long time.
  • When the brake fluid pressure is held for a long time.

PROBABLE CAUSES

  • Damaged wiring harness and connectors
  • External noise interference
  • Malfunction of wheel speed sensor
  • ASC-ECU malfunction
  • 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
  • Improper installation of the wheel speed sensor
  • Deformation of the wheel speed detection encoder
  • Disturbance of magnetisation pattern for wheel speed detection encoder
  • Missing teeth of the wheel speed detection encoder

DIAGNOSIS PROCEDURE

STEP 1. M.U.T.-III CAN bus diagnosis
Use M.U.T.-III to diagnose the CAN bus lines.

Q. Is the check result normal?
Go to Step 3.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting ). On completion, go to Step 2.

STEP 2. Diagnosis code recheck after resetting CAN bus lines

Q. Is the diagnosis code No. C1049 set?
Go to Step 3.
This diagnosis is complete.

STEP 3. M.U.T.-III diagnosis code
Check that the diagnosis codes No. C102B, C1032, C1035, and C1044 are also set.

Q. Are the diagnosis codes No. C102B, C1032, C1035, and C1044 also set?
Carry out the diagnosis for the relevant diagnosis codes, and then go to Step 5.
Go to Step 4.

STEP 4. Check whether the diagnosis code is reset.

  • Drive the vehicle at 20 km/h or more.

Q. Is the diagnosis code No. C1049 set?
Replace the ASC-ECU, and then go to Step 5.
This diagnosis is complete.

STEP 5. Check whether the diagnosis code is reset.

  • Drive the vehicle at 20 km/h or more.

Q. Is the diagnosis code No. C1049 set?
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunction ).
This diagnosis is complete.