Inspection Procedure 9: ABS operate too frequently: Diagnosis

STEP 1. Check the wheels and the tires.
Carry out the following check.
- Size check of wheels and tires
- Tire wear and deterioration statuses
- Check the tire pressure.
  NOTE: For the tire pressure, refer to the tire pressure label attached to the lower section of driver's side door striker.
Q: Is the check result normal?
1. YES: Go to Step 2.
2. NO: Correct the wheels and tires in good condition. Then go to Step 9.
STEP 2. DTC check
Use scan tool to check the DTC for the ABS system (Refer to DIAGNOSTIC TROUBLE CODE CHART ).

Q: Is the check result normal?
1. YES: Go to Step 3.
2. NO: Carry out the diagnosis for the DTC (Refer to DIAGNOSTIC TROUBLE CODE CHART ). Then go to Step 9.
STEP 3. Check of brake system related components other than hydraulic unit (integrated with ABS-ECU)
At the same time with the following checks, also check that no parts other than the genuine parts are mounted.
- Brake pad check (Refer to BRAKE PAD CHECK ).
- Brake disk runout check (Refer to BRAKE DISK CHECK ).
- Brake drag force check (Refer to FRONT DISC BRAKE ASSEMBLY or REAR DISC BRAKE ASSEMBLY ).
Q: Is the check result normal?
1. YES: Go to Step 4.
2. NO: Repair or replace the part(s) having damage or other problems. Then go to Step 9.
STEP 4. Wheel alignment check
At the same time with the following checks, also check that no parts other than the genuine parts are mounted.
- Front wheel alignment check (Refer to FRONT WHEEL ALIGNMENT CHECK AND ADJUSTMENT ).
- Rear wheel alignment check (Refer to REAR WHEEL ALIGNMENT CHECK AND ADJUSTMENT ).
Q: Is the check result normal?
1. YES: Go to Step 5.
2. NO: Repair or replace the part(s) having damage or other problems. Then go to Step 9.
STEP 5. M.U.T.-III data list
Check the following data list (Refer to DATA LIST REFERENCE TABLE ).
- Item No. 01: FL wheel speed sensor
- Item No. 02: FR wheel speed sensor
- Item No. 03: RL wheel speed sensor
- Item No. 04: RR wheel speed sensor
Q: Is the check result normal?
1. YES: Go to Step 7.
2. NO: Go to Step 6.
STEP 6. Wheel speed sensor check
Check that no non-genuine electronic device or no wiring harness of other than genuine electronic device is mounted near the wheel speed sensor (at wheel speed detection section and wiring harness section) (Refer to WHEEL SPEED SENSOR ).

Q: Is the check result normal?
1. YES: Go to Step 7.
2. NO: Remove the non-genuine electronic device or the wiring harness of non-genuine electronic device. Then go to Step 9.
STEP 7. Hydraulic unit check
Carry out the following actuator tests, and check if they work normally (Refer to DATA LIST REFERENCE TABLE ).
- Item No. 01: FL wheel ABS
- Item No. 02: FR wheel ABS
- Item No. 03: RL wheel ABS
- Item No. 04: RR wheel ABS
Q: Is the check result normal?
1. YES: Go to Step 8.
2. NO: Replace the hydraulic unit (integrated with ABS-ECU) (Refer to HYDRAULIC UNIT ). Then go to Step 9.
STEP 8. ABS operation check
Q: Is the check result normal?
1. YES: Intermittent malfunction (Refer to HOW TO COPE WITH INTERMITTENT MALFUNCTION ).
2. NO: Replace the hydraulic unit (integrated with ABS-ECU) (Refer to HYDRAULIC UNIT ). Then go to Step 9.
STEP 9. ABS operation check
Q: Is the check result normal?
1. YES: The procedure is complete.
2. NO: Return to Step 1.