ABS OR TCS*1 OPERATES FREQUENTLY/TCS DOES NOT WORK CORRECTLY *1: DSC SYSTEM FUNCTION CONTAINS TRACTION CONTROL FUNCTION, TCS/DSC INDICATOR LIGHT GOES ON AND OFF WHILE TCS OPERATES [ELECTRONICALLY CONTROLLED BRAKE SYSTEM]

id040309892300

Troubleshooting item

ABS or TCS*1 operates frequently

TCS does not work correctly

*1: DSC system function contains traction control function, TCS/DSC indicator light goes on and off while TCS operates
Possible cause
•  There is a difference in size or air pressure between front and rear tires.
•  Incorrect ABS wheel-speed signal is inputted to electronically controlled brake unit.
•  There is a malfunction in engine control system. (TCS malfunction)
System wiring diagram
Not applicable
Connector diagram
Not applicable

•  When performing an asterisked (*) troubleshooting inspection, shake the wiring harness and connectors while doing the inspection to discover whether poor contact points are the cause of any intermittent malfunctions. If there is a problem, check to make sure connectors, terminals and wiring harness are connected correctly and undamaged.

Diagnostic procedure

Step

Inspection

Results

Action
1
CONFIRM ELECTRONICALLY CONTROLLED BRAKE UNIT AND PCM DTC
•  Retrieve the electronically controlled brake unit DTC using the M-MDS.
•  Retrieve the PCM DTC using the M-MDS, if the traction control function has problem.
•  Are any DTCs present?
Yes
Go to the applicable DTC inspection.
(See DTC TABLE [ELECTRONICALLY CONTROLLED BRAKE UNIT].)
(See DTC TABLE [PCM (SKYACTIV-G)].)
No
Go to the next step.
2
INSPECT TIRE SIZE AND AIR PRESSURE
•  Inspect tire size and air pressure.
•  Tire size and air pressure as specified?
Yes
Go to the next step.
No
Replace with specified tires and adjust tire air pressure, and perform the repair completion verification.
(See TIRE PRESSURE ADJUSTMENT.)
*3
INSPECT ABS WHEEL-SPEED SENSOR
•  Inspect for each ABS wheel-speed sensor.
•  Is the ABS wheel-speed sensor normal?
Yes
Found malfunctioning part according to the “INTERMITTENT CONCERN TROUBLESHOOTING”.
(See TROUBLESHOOTING PROCEDURE [(E)].)
No
ABS wheel-speed sensor installation inspection:
•  Inspect the ABS wheel-speed sensor for looseness and confirm it is securely adhered.
ABS sensor rotor installation inspection:
•  Inspect the ABS sensor rotor for poor installation.
Repair or replace any malfunctioning parts according to the inspection result.
(See FRONT ABS WHEEL-SPEED SENSOR REMOVAL/INSTALLATION.)
(See REAR ABS WHEEL-SPEED SENSOR REMOVAL/INSTALLATION.)
Perform the repair completion verification.
Repair completion verification
VERIFY THAT MALFUNCTION SYMPTOMS DO NOT RECUR AFTER REPAIR
•  Install/connect the part removed/disconnected during the troubleshooting procedure.
•  Has the malfunction symptom been eliminated?
Yes
Complete the symptom troubleshooting.
Explain to the customer what has been repaired.
No
Refer to the controller area network (CAN) malfunction diagnosis flow to inspect for a CAN communication error.
(See CONTROLLER AREA NETWORK (CAN) MALFUNCTION DIAGNOSIS FLOW.)
If the CAN communication is normal, perform the diagnosis from Step 1.