DTC C1041: Abnormality in periodical signal for FL wheel speed sensor: Diagnosis

Required Special Tools: 

• MB991958 Scan Tool (M.U.T.-III Sub Assembly)
  • MB991824: Vehicle Communication Interface (V.C.I.)
  • MB991827 M.U.T.-III USB Cable
  • MB991910 M.U.T.-III Main Harness A
• MB991997: ASC check harness

1. STEP 1. Using scan tool MB991958, diagnose the CAN bus lines. 

   Using scan tool MB991958, diagnose the CAN bus lines.

   Q: Is the check result normal? 

   YES  : Go to Step  3.

   NO  : Repair the CAN bus lines. (Refer to TROUBLESHOOTING .) After repairing the CAN bus line, go to Step 2.

2. STEP 2. DTC recheck after repairing the CAN bus line 

   Q: Is DTC C1041 set? 

   YES  : Go to Step 3.

   NO  : This diagnosis is complete.

3. STEP 3. Wheel bearing looseness check 
   NOTE: Wheel bearing looseness may increase the gap between the wheel speed sensor and the wheel speed detection magnet encoder. Check the wheel bearing < FL > for looseness. (Refer to ON-VEHICLE SERVICE .)

   Q: Is the check result normal? 

   YES  : Go to Step 4.

   NO  : Replace the front hub assembly. (Refer to FRONT AXLE HUB ASSEMBLY .)

4. STEP 4. Check of wheel speed detection encoder 

   Check the encoder for adhesion of foreign materials or deformation.

   Fig 1: Identifying Oil Seal, Hub, Magnetic Encoder And Wheel Bearing

   Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.

   Q: Is the check result normal? 

   YES  : Go to Step 5.

   NO (Adhesion of foreign materials)  : Clean the encoder so as not to disturb the magnetization pattern on the encoder while taking care of the magnet, magnetic substance, and magnetic attraction.

   NO (Deformation)  : Replace the front hub assembly. (Refer to FRONT AXLE HUB ASSEMBLY .)

5. STEP 5. Check whether the DTC is reset. 
   1. Erase the diagnostic trouble code.
   2. Drive the vehicle at 12mph (20 km/h) or more.
      NOTE: The ABS warning light does not turn OFF in some cases unless the vehicle runs at 12mph (20 km/h) or higher.

   Q: Is DTC C1041 set? 

   YES  : Replace the hydraulic unit (incorporates in ASC-ECU).(Refer to HYDRAULIC UNIT  .) Then go to Step 6.

   NO  : Intermittent malfunction. (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION .)

6. STEP 6. Check whether the DTC is reset. 
   1. Erase the diagnostic trouble code.
   2. Drive the vehicle at 12mph (20 km/h) or more.
      NOTE: The ABS warning light does not turn OFF in some cases unless the vehicle runs at 12mph (20 km/h) or higher.

   Q: Is DTC C1041 set? 

   YES  : Return to Step  1.

   NO  : This diagnosis is complete.