DTC C102A: Mutual monitoring of RL 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

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

Q: Is the check result normal?
1. YES: Go to Step 3.
2. NO: Repair the CAN bus lines (Refer to CAN BUS DIAGNOSTICS TABLE ). On completion, go to Step 2.
STEP 2. DTC recheck after resetting CAN bus lines
Q: Is DTC C102A set?
1. YES: Go to Step 3.
2. NO: The procedure is complete.
STEP 3. Using scan tool MB991958, check the DTC
Check that the DTC C1020 is also set.

Q: Is DTC C1020 also set?
1. YES: Perform the diagnosis for the DTC C1020 (Refer to DTC C1020: ABNORMALITY IN RL WHEEL SPEED SENSOR CIRCUIT ).
2. NO: Go to Step 4.
STEP 4. Check wheel speed sensor < RL > installation
Check how the wheel speed sensor < RL > is installed (Disconnection of wheel speed sensor < RL >, loose mounting bolt, etc.).

Q: Is the check result normal?
1. YES: Go to Step 5.
2. NO: Reinstall the wheel speed sensor < RL > correctly (Refer to WHEEL SPEED SENSOR ). Then go to Step 5.
STEP 5. Check for wheel speed sensor < RL > output current
Refer to WHEEL SPEED SENSOR OUTPUT CURRENT MEASUREMENT .

Q: Is the check result normal?
1. YES: Go to Step 6.
2. NO: Replace the wheel speed sensor < RL > (Refer to WHEEL SPEED SENSOR ). Then go to Step 9.
STEP 6. Check for wheel bearing looseness
NOTE:
- Loose wheel bearing may increase the gap between the wheel speed sensor < RL > and the wheel speed detection magnet encoder.
- Check the wheel bearing < RL > for looseness (Refer to ON-VEHICLE SERVICE ).
Q: Is the check result normal?
1. YES: Go to Step 7.
2. NO: Replace the rear wheel hub assembly < RL > (Refer to REAR AXLE HUB ASSEMBLY ). Then go to Step 10.
STEP 7. Check wheel speed detection encoder
Check the encoder for adhesion of foreign materials or deformation.

Q: Is the check result normal?
1. YES: Go to Step 8.
2. NO (Adhesion of foreign materials): Remove the foreign materials and clean the encoder so as not to disturb the magnetization pattern on it while taking care of the magnet, magnetic substance, and magnetic attraction. Then go to Step 10.
3. NO (Deformation): Replace the rear wheel hub assembly < RL > (Refer to REAR AXLE HUB ASSEMBLY ). Then go to Step 10
  
  Fig 1: Identifying Ball Bearing, Rear Hub Assembly, Magnetic Encoder
  Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.
STEP 8. Check whether the DTC is reset.
1. Erase the DTC.
2. Drive the vehicle at 12mph (20 km/h) or higher.
  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 C102A set?
1. YES: Replace the wheel speed sensor < RL > (Refer to WHEEL SPEED SENSOR ). Then go to Step 9.
2. NO: Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTIONS ).
STEP 9. Check whether the DTC is reset.
1. Erase the DTC.
2. Drive the vehicle at 12mph (20 km/h) or higher.
  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 C102A set?
1. YES: Replace the hydraulic unit (integrated with ABS-ECU) (Refer to HYDRAULIC UNIT ). Then go to Step 10.
2. NO: The procedure is complete.
STEP 10. Check whether the DTC is reset.
1. Erase the DTC.
2. Drive the vehicle at 12mph (20 km/h) or higher.
  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 C102A set?
1. YES: Return to Step 1.
2. NO: The procedure is complete.