The HECU receives wheel speed signals from the four wheel speed sensors.
The wheel signals are converted to voltage signals by the signal converting circuit and given as input to the HECU.
The HECU checks an open or short in the circuit of the wheel speed sensor.
If more than one wheel speed sensor malfunctions, the system stops.
DTC No | Condition | Possible Cause |
C1200 (FL) C1203 (FR) C1206 (RL) C1209 (RR) | If the sensor signal current is continuously out of the specified range of 4 mA ±10％ ~ 22 mA ±10％ for 140msec, the failure is detected. | - Open/short in circuit of wheel speed sensor - Faulty wheel speedsensor - Faulty HECU |
Sensor malfunction without ABS control :
- One wheel sensor malfuntion
Only the ABS, TCS(ESP) functions are inhibited. the ABS, TCS(ESP) warning lamps are ON, but the EBD warning lamp is OFF.
- More than two wheels malfunction
The system stops. the ABS, TCS(ESP) and the EBD functions are inhibited. the ABS, TCS(ESP) and the EBD warning lamps are ON. The valve relay and all solenoids are OFF.
Sensor malfunction with ABS control :
- One front wheel malfunction
Inhibit the ABS control of a wheel with a malfunctioning sensor and maintain the ABS control of other wheels.
After the ABS control has completed, the ABS, TCS(ESP) functions are inhibited. The ABS, TCS(ESP) warning lamps are ON but the EBD warning lamp is OFF.
- One rear wheel malfunction
Inhibit ABS control of both front wheels and the pressure of both rear wheels is decreased. After the controller completes the ABS control, Only the ABS, TCS(ESP) functions are inhibited. The ABS, TCS(ESP) warning lamps are ON but the EBD warning lamp is OFF.
- More than two wheels malfunction
The system stops. the ABS, TCS(ESP) and the EBD functions are inhibited. The ABS, TCS(ESP) and the EBD warning lamps are ON. The valve relay and all solenoids are OFF.
CHECK POWER FOR WHEEL SPEED SENSOR
Measure the voltage between an appropriate wheel sensor(+) terminal and the body ground (see the table below).
DTC | Terminal |
C1200 (Font-left) C1203 (Font-right) C1206 (Rear-right) C1209 (Rear-right) | 1 19 5 23 |
Specification:Battery positive(+)
Is the voltage within the specification?
▶Repair short to power in the (+) circuit between the HECU and the appropriate wheel sensor.
▶Check output of the wheel speed sensor
CHECK OUTPUT OF THE WHEEL SPEED SENSOR
Check the volrange between terminals (see the table below)of the HECU and the body ground.
DTC | Terminal |
C1200 (Font-left) C1203 (Font-right) C1206 (Rear-right) C1209 (Rear-right) | 2 20 6 |
Specification:0.4~2.2V
Is the voltage within the specification?
▶Replace the wheel sensor and recheck.
▶Repair the wire between the HECU and the wheel speed sensor.
