Functional Test

The EPB incorporates a vehicle inspection mode. The inspection mode allows a functional test of the EPB to be done on a rolling brake tester.

Details of the test are below.

NOTE: 'HU Mode 'is a function in the Jaguar Land Rover (JLR) approved diagnostic equipment.

Enabling Rolling Brake Tester Mode

Transmission is in NEUTRAL (N).
The ignition is switched ON, with the engine either running or not (Power Mode 6 or 7).
Brake pedal is not pressed.
EPB is not applied nor applying nor releasing.
EPB switch is in neutral.
Wheel speeds on the axle clamped by the EPB are equal.
Wheel speeds are between 1.8 km/h (1 mph) and 9 km/h (5.5 mph) for more than 3 seconds.

The yellow park brake warning indicator lamp will illuminate when all the roller bench test mode enable conditions are true. This indicates that the roller bench test 'HU Mode' is enabled.

Switch Response

When the mode has been enabled, the system shall behave as follows:

When the EPB switch is applied, the EPB mechanism applies a partial apply force. The value of the partial apply force is dependant on the manufacturer of the brake components.
If the switch is held in this position, the force shall be constant for 1 second. The force then increases. The value of the increase is dependant on the manufacturer of the brake components.
While the switch remains in the apply position, the clamp force increment behavior repeats. The clamp force repeats until the EPB mechanism reaches a value provided by the manufacturer of the brake components.
If the switch moves to neutral, the EPB shall remain at the current clamp force.

If the switch moves to release position, the EPB shall remove all the current brake force and return to release position with no force present.

Function Exit

The system will exit this mode if any of the following are true:

When the EPB mechanism has achieved full clamp force.
Both wheel speeds on the axle clamped by the EPB exceed 10 km/h for at least 1 second.
Gear selector position is not NEUTRAL (N).
EPB fault (any fault that would prevent full EPB functionality).
Power Mode moves lower than Power Mode 6 (ignition ON).
Any of the enable conditions cannot be confirmed due to a fault.

When the EPB actuators are in a transition position and the 'HU Mode' function stops, the EPB releases all EPB mechanism clamp force.