The QX30 is equipped with an Electric Parking Brake (EPB) that can be applied even with the ignition OFF or the key removed. Push the handle to apply the parking brake. To release the parking brake, place the ignition in the ON position and pull the parking brake handle. The park indicator light comes on to show that the parking brake is applied if the ignition is ON.
Component Locations
The EPB system consists of two electric parking brake actuators (one on each rear brake caliper), a parking brake switch that is located under the rotary lighting switch, and a parking brake control unit installed in the rear luggage compartment.
Parking Brake Actuator
NOTE:
The EPB actuator motors clamp and release the brake pads.
System Diagram
The electric parking brake control module sends a signal to the EPB actuator motors to clamp or release the brake pads. The electric parking brake control unit monitors the rise in electrical current as the rear brake pads clamp the rear brake rotor discs. Clamping is stopped once the electrical current reaches a set threshold.
The electric parking brake control module has the following tasks:
- Reading in of signals
- Evaluation of input factors
- Actuation of the LH and RH electric parking brake actuator motors
The TCM is used to transmit the shift position signal to the EPB control module by CAN communication (via ECM).
Electric Parking Brake Operation
- Pushing the parking brake switch applies the parking brake up to a vehicle speed of 2 mph (3 km/h).
- The parking brake actuators clamp the brake pads onto both rear brake rotors.
- When the electric parking brake is applied, the red park indicator lamp illuminates in the combination meter.
- Pulling the parking brake switch releases the parking brake actuators from clamping the brake pads onto both rear brake calipers.
NOTE:
If the electric parking brake is not released as a result of a malfunction, the combination meter outputs a warning message via the vehicle information display and sounds a warning.
EPB Automatic Application or Release
The electric parking brake is automatically applied when:
- Intelligent cruise control (if equipped) brings the vehicle to a standstill.
- OR -
- Intelligent Park Assist (if equipped) is keeping the vehicle stationary.
The electric parking brake is automatically released when the shift selector is in D or R. The Parking Brake Automatic Release function is performed as soon as a sufficiently high drive torque exists at the wheels of the front axle in order to overcome the grade resistance for the prevailing road gradient. However, to prevent rolling downhill, if the driver door is opened when in D or R, the parking brake is automatically applied and the transmission P range is selected, (as long as the vehicle is traveling at 2 mph or less).
NOTE:
The electric parking brake is not automatically applied if the engine is switched OFF by the ECO Stop/Start function.
Emergency Mode
At speeds above 2.5 mph (4 km/h), if the parking brake switch is pressed and held:
- The ABS reduces excess speed by ABS pump activation to build braking pressure at the calipers.
- At and below 2.5 mph (4 km/h) the parking brake is applied.
- The longer the electric parking brake switch is depressed, the greater the braking force.
- If the parking brake switch is released at any point, the parking brake is released.
EPB Warning Indicators
The electric parking brake warning lamp illuminates (yellow) to help warn the driver of the following conditions:
- Emergency stop using the electric parking brake
- Malfunction in the electric parking brake system
- Electric parking brake inoperative
The electric parking brake indicator lamp illuminates (red) or blinks to help warn the driver of the following conditions:
- The parking brake is engaged
- The electric parking brake was released while the ignition switch is OFF
- A condition for automatic release of the electric parking brake is not fulfilled
- An emergency stop using the electric parking brake
- A malfunction is detected in the electric parking brake system
- The electric parking brake is inoperative
The function of the electric parking brake is dependent on the battery voltage. If battery voltage is low or if there is a malfunction in the system, it may not be possible to apply or release the electric parking brake with the EPB switch.
If the battery negative terminal has been disconnected with the parking brake ON, or, if the battery voltage is outside the permissible range, it may not be possible to release the electric parking brake with the EPB switch.
What to do if it is not possible to release the electric parking brake switch:
1. Rectify the cause of the over voltage or under voltage, e.g., by charging the battery or restarting the engine.
2. Release the electric parking brake with the EPB switch.
If the electric parking brake still cannot be released:
1. Disconnect the parking brake actuator harness connector from the rear caliper assembly.
2. Remove the parking brake actuator.
3. Rotate the rear brake caliper assembly spindle part clockwise.
NOTE:
If the system fails with the parking brake applied, the EPB must be manually released. The EPB piston spindle assemblies will have to be released manually by winding them back clockwise, using a 7 mm hex wrench.
Function Check
NOTE:
The electric parking brake carries out a function check at regular intervals when the engine is switched OFF. Noises that occur during the function check are normal.
Service Points
When performing brake pad replacement, a service position can be activated to fully wind back the brake caliper pistons. You’ll want to set the service position to prevent the system from inadvertently reapplying the parking brake while you are working on the system.
NOTE:
The service position can be activated with or without CONSULT-III plus.
To set the service position with CONSULT-III plus:
1. The vehicle must be on a level surface.
2. Release the parking brake.
3. Select “EHS/PKB”, “WORK SUPPORT”, and “Electrical contact actuator/brake clearance setting” according to this order.
4. Touch “START”.
To manually set the service position without CONSULT-III plus:
1. Turn the key to the ACC accessory position.
2. Ensure the combination meter displays the “Trip” menu item showing the mileage screen reading.
3. Press and hold down the steering wheel phone switch and within 1 second, additionally press and hold the OK button for 5 seconds.
NOTE:
After approximately 5 seconds, the vehicle information displays the workshop menu options: “Vehicle data”, “Dynamometer”, “Pad replacement”, and “Maintenance” tabs.
4. Press the Scroll up/down arrows until “Pad replacement” is highlighted, and then press OK.
NOTE:
The vehicle information display will then show “To move to fitting position: OK / To cancel: Back.
5. Press OK to confirm.
Never depress the brake pedal during the “Move to fitting position”, as you can damage the spindle in the brake caliper.
The vehicle information display shows “Fitting position reached / To exit fitting position: OK.
6. Turn the ignition switch to the OFF position to prevent unintended movement away from the assembly fitting position.
NOTE:
Refer to the ESM for brake assembly removal/installation, inspection and repair procedures.
To Exit the Fitting Position:
1. Place the ignition in the ACC position.
2. The vehicle information display shows “Fitting position reached / To exit fitting position: OK.
3. Press the “OK” button to Confirm.
NOTE:
The “Caution Exiting fitting position” is shown in the information display for the duration of the fitting position exit.
4. When the process has finished, the “Fitting position has been exited, To confirm: OK” indicator appears in the information display.
5. Press the “OK” button to Confirm.
6. Exit the workshop menu with “Back” button.
7. Turn ignition switch to OFF position.
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