This code shows in case that there is no signal from any of the wheel speed sensors caused by an air gap, etc.
DTC DETECTING CONDITION
DTC No
Condition
Cause
C1202 (FL)C1205 (FR)C1208 (RL)C1211 (RR)
Large AirGap :
This monitoring is performed for the period that the minimum velocity rises from 2km/h to 10km/h.
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When the minimum wheel velocity is 2km/h and the velocity of other wheels exceed 10km/h with the less than acceleration of 0.4g, the controller start comparing the velocity of other wheels except the min. wheel. if their difference below 4km/h is continued for 140msec, Otherwise, if their difference beyond 4km/h or more than 0.4g is continued for 2 minutes.
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In＜0.4g, when the velocity of more than two wheels is 2km/h and the max. wheel velocity exceeds 10km/h, the condition is continued for 20 sec. Otherwise, In more than 0.4g, the condition is 2 minutes.
-
After velocity of 4 wheel exceeds 10km/h, when velocity of 1 wheel or 2 wheel is 2km/h and difference of other 2 wheel velocity is less than 4km/h under that those velocity is more than 10km/h, if that conditions are continued for 12 seconds.
Long Term ABS mode :
-
During the ABS control cycle, if the wheel velocity of 2km/h is lasted for more than 12sec.
-
If the ABS control cycle is continued for more than 36sec.
-
Faulty installing of wheel speed sensor
-
Open/short in circuit of wheel speed sensor
-
Faulty wheel speed sensor
-
Faulty rotor or wheel bearing
-
Faulty HECU
FAILSAFE FUNCTION
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 and 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 and 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.
INSPECTION PROCEDURE
1.
CHECK AIR GAP BETWEEN WHEEL SPEED SENSOR AND TONE WHEEL.
Visually check the installing of wheel speed sensors and rotors(see the table below).
Specification : 0.5~1.5mm
DTC
Appropriate wheel sensor
C1202
C1205
C1208
C1211
Front - left wheel sensor
Front - right wheel sensor
Rear- left wheel sensor
Rear- right wheel sensor
note
The mounting bolt shall be tightened properly and there is no clearance is allowed between the sensor and front steering knuckle or rear axle carrier.
Is the air gap within the specification?
▶Reinstall or replacece if neccessary, wheel speed sensors in trouble.
▶Check resistance between terminals of wheel speed sensor.
2.
CHECK RESISTANCE BETWEEN TERMINALS OF WHEEL SPEED SENSOR.
(1)
Disconnect the HECU connector.
(2)
Measure the resistance between wheel speed sensors(+) and (-) circuit terminals(see the table below).
DTC
TERMINAL
(+)side
(-)side
C1202 (Front - left)
C1205 (Front - right)
C1208 (Rear - left)
C1211 (Rear - right)
1
19
5
23
2
20
6
22
Is the resistance within less than 1Ω?
1)There is a short in the circuit between the HECU and the wheel speed sensor.
2)Replace the wheel speed sensor.
▶Check speed of each wheel.
3.
CHECK SPEED OF EACH WHEEL
Check if the speed of each of four wheel properly represents the speed of a vehicle, increasing the speed of the vehicle till 60km/h.
Is the speed of each wheel the same as that of the vehicle?
(1)
Check any foreign objects on the rotor of the wheel in trouble.
(2)
Check if the exitor is genuine.
After cleaning the DTC and driving the vehicle at 40 km/h speed or more, if the ABS warning lamp is ON and the same DTC shows again, replace the HECU and recheck.
