Kia Optima: ESC (Electronic Stability Control) System / Rear Wheel Speed Sensor

Disconnect the (-) battery terminal.

Remove the rear wheel and tire.

(Refer to Suspension System - "Wheel")

Remove the rear brake disc.

(Refer to Brake System - "Rear Brake Disc")

Disconnect the rear wheel speed sensor connector (A).

Remove the hub assembly and dust cover (A) after loosening the mounting bolts.

Be careful not to drop the rear hub assembly when loosening the bolts.

Remove the rear wheel hub bearing assembly.

(Refer to Driveshaft and axle - "Rear Axle Assembly")

Fix the rear hub bearing assembly (A) on the vise.

• When placing on the vise, use a cloth not to be damaged the hub bearing assembly. • Be careful not to use excessive force on the vise may damage the hub bearing assembly.

Check the direction of the sensor cap (A).

Before removing the sensor cap, check the direction of the sensor cap connector.

Remove the sensor cap by hammering on a gap between sensor cap and hub bearing assembly using a scraper (A).

• In order to widen the gap little by little, hammering around the bearing cap 10-20 times. • When removing the sensor cap, remove it in a straight direction not to damage the tone wheel or encoder. • Be careful not to damage the hub bearing assembly when using the hammer.

Check for distortion of damage of the tone wheel or encoder (A).

• Check if damaged the tone wheel or encoder after removing the sensor cap and replace the hub bearing if it was deformed. • If the tone wheel is deformed, it may trigger the MIL ON or other problems.

Position the sensor cap to the same direction of sensor cap connector (A) as you checked before removing.

Before installing the sensor cap, do not let any foreign material and contaminant into the hub bearing assembly.

Install the sensor cap (A) with the special service tool (09527-AL400).

• Be careful not to tilt to one side when installing the sensor cap as it may damage the tone wheel or encoder. • When sensor cap installation, hammering it until the gap disappeared between the sensor cap and hub bearing assembly. • Special Service Tools guide. SST No. SST Inner diameter Sensor cap outer diameter 09527-2W110 Φ82.1 Φ81.2, Φ81.4 09527-1S010 Φ58.9 Φ58.4 09527-AL100 Φ60 Φ59.5 09527-AL200 Φ65.9 Φ65.3 09527-AL300 Φ67.4 Φ67.2 09527-AL400 Φ73.2 Φ72.6 09527-AL500 Φ87.2 Φ86.6

Install the rear wheel hub bearing assembly.

(Refer to Driveshaft and axle - "Rear Axle Assembly")

Measure the output voltage between the terminal of the wheel speed sensor and the body ground.

In order to protect the wheel speed sensor, when measuring output voltage, a 100Ω resister must be used as shown.

Compare the change of the output voltage of the wheel speed sensor to the normal change of the output voltage as shown below.

V_low : 0.59V - 0.84V

V_high : 1.18V - 1.68V

Frequency range : 1 - 2,500 Hz

Install in the reverse order of removal.