C1204

DTC C1201 FL WHEEL SENSOR-RANGE/PERFORMANCE
DTC C1204 FR WHEEL SENSOR-RANGE/PERFORMANCE
DTC C1207 RL WHEEL SENSOR-RANGE/PERFORMANCE
DTC C1210 RR WHEEL SENSOR-RANGE/PERFORMANCE

COMPONENT LOCATION:

GENERAL DESCRIPTION
The wheel speed sensor is the essential component the ABS ECU uses to calculate vehicle speed and to determine whether wheel lock occurs. For example, rear wheel speed signal is used as a reference value, for vehicle speed, in front wheel drive vehicles, and if a difference between front and rear wheel speed occurs, then ABS control is performed. Wheel speed sensor is active hall-sensor type and good at temperature and noise characteristic. Digital waveform is produced as tone wheel rotate according as hall sensor principle. Frequency of duty waveform is changed in proportion to rotation of tone wheel and HECU calculate vehicle speed by this frequency.

DTC DESCRIPTION
The ABS ECU monitors the wheel speed sensor signal continuously. This code is set when an abnormal signal due to air gap problem or an abnormal speed change ratio are detected at the vehicle speed between 10 km/h to 80 km/h. Warning lamp is turned OFF unless additional faults are detected when the IG KEY is turned ON again, and wheel speed is more than 12 Km/h.

DTC DETECTING CONDITION:

MONITOR SCANTOOL DATA
1. Engine "ON".
2. Connect scantool to Data Link Connector (DLC).
3. Start and drive vehicle in gear and maintain vehicle speed at or above 12 km/h (7 mph)
4. Monitor the "Wheel speed sensor" parameter on the Scantool.





5. Is parameter displayed within specifications?
YES
> Fault is intermittent caused by poor connection in wheel speed sensor harness and/or HECU's connector or was repaired and HECU memory was not cleared. Go to "Compost Inspection" procedure.
NO
> Check for improper installation of wheel speed sensor. If NG, repair as necessary and then go to "Verification of vehicle Repair" procedure.
> Check for damage of rotor teeth or wheel bearing. If NG, repair as necessary and then go to "Verification of vehicle Repair" procedure.
> Substitute with a known-good Wheel speed sensor and check for proper operation. If problem is corrected, replace Wheel speed sensor and then go to "Verification of Vehicle Repair" procedure.
> If OK, Go to "Component Inspection" Procedure.

COMPONENT INSPECTION
1. Ignition "OFF".
2. Engine "ON".
3. Start and drive vehicle in gear and maintain vehicle speed at or above 12 km/h (7 mph).
4. Does warning lamp remain On?
YES
> Substitute with a known-good HECU and check for proper operation. If problem is corrected, replace HECU and then go to "Verification of Vehicle Repair" procedure.
NO
> Fault is intermittent caused by open or short of wheel speed sensor harness, inoperative wheel speed sensor. Go to the applicable troubleshooting procedure.

VERIFICATION OF VEHICLE REPAIR
After a repair, it is essential to verify that the fault has been corrected.
1. Connect scantool and select "Diagnostic Trouble Codes(DTCs)" mode
2. Using a scantool, Clear DTC.
3. Operate the vehicle within DTC Detecting Condition in General Information.(Start and drive vehicle in gear and maintain vehicle speed at or above 12 km/h (7 mph))
4. Are any DTCs present?
YES
> Go to the applicable troubleshooting procedure.
NO
> System performing to specification at this time.