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# Brakes - Electric Park Brake (EPB) Won't Release

NUMBER 038
GROUP Chassis
DATE August 2012
MODEL Optima (QF) 2012MY
SUBJECT:
ELECTRIC PARKING BRAKE (EPB) RELEASE METHOD USING GDS
This bulletin provides information relating to releasing the Electric Parking Brake (EPB) on 2013 MY Optima SX-L using GDS. This may be helpful in cases where the brake inadvertently remains "on" or applied, for example when it is not possible to release the brake using the drivers EPB control switch. Although a mechanical "emergency" EPB release is available, it requires the removal of the EPB motor from the rear calipers and a manual rotation of the caliper spindle, as well as re-setting and re-assembly afterwards. In cases where vehicle electrical power and scan tool communication are available, it may be possible to release the EPB using GDS. Follow the procedure below to control/release the brake without disassembly/re-assembly. Additional EPB information is available in the Shop manual on KGIS.
Service Procedure:
1. If vehicle battery is discharged or RKE or Smart Key system malfunctions and the door is locked, open the door using the mechanical key.
2. Make sure the battery state of charge is normal. If necessary, charge the battery.
3. Connect GDS to the data link Connector (DLC) of a vehicle.
4. Turn the ignition switch to the "ON" position.
NOTICE
5. Select vehicle model in the initial screen.
6. Select "EPB" and click "OK."
7. Select "Actuation Test."
8. Activate "Actuator Control - release," and then value of "Actuator Direction" will be changed from "Applied" to "released."
NOTICE
If the EPB system is not functioning properly as indicated below, and the EPB cant be released using GDS, then EPB should be released mechanically.
- EPB ECU malfunction
- Actuator malfunction
- ECU, actuator wiring - short/open
- CAN bus error
- EPB Actuator failure - short/open, stuck, or broken
EPB Emergency Release Procedure:
CAUTION
WARNING
1. place tire wedges/chocks so vehicle does not move when EPB is released.
2. The EPB motor is held on by two (2) 5mm hex screws (A). Loosen and remove both screws. Once the motor is removed, the brake can be released by turning (B) in 1/2 to 1 turn clockwise, using a 5mm hex. once electrical functionality of EPB is restored / repaired, (B) needs to be rotated back to its original position.
Additional information and more detail is available in the Shop Manual on KGIS.
3. Reinstall motor and tighten screws (A). Confirm Apply/release function of EPB using EPB switch.