34 00 xxx Parking brake function check
IMPORTANT:
Only brake test stands with test speeds of 2.5-6 km/h may be used.
Before driving onto the brake tester, switch off the Hill Descent Control (HDC) and leave it switched off for the duration of the brake testing procedure.
The HDC indicator lamp must not light up!
NOTE:
It is possible for the HDC indicator lamp to go out or not to light up even when HDC mode is activated if HDC is temporarily unavailable on account of high operating temperature.
Necessary preliminary tasks:
- The brakes must be at normal operating temperature. To that end, warm up and dry off the brake discs by braking the vehicle a few times.
IMPORTANT:
For testing, turn on the ignition and make sure the transmission selector lever is in the "N" position.
NOTE:
E65, E66, E70, E71, E72 only:
Comfort access: insert remote control in ignition lock.
If the remote control is not in the ignition lock, selector lever position "P" is automatically engaged.
Failure to comply with this instruction may result in damage to the test stand or to the vehicle.
Parking brake:
IMPORTANT:
The test may only be carried out with the engine switched off, the transmission selector lever in the "N" position and the ignition switched on.
NOTE:
The electromechanical parking brake can not be tested on a plate test stand!
- Drive the rear wheels of the vehicle onto the brake tester
- Move transmission selector lever to "N" position
- Turn off engine.NOTE: When the engine is running, additional braking effect will otherwise be exerted by the DSC system on all the wheels.
- Turn on ignition
- Start roller dynamometer
- Activate parking brake, pull button (1) for this purpose
NOTE:
Parking brake indicator lamp in instrument panel lights up red. Duo-servo brake (actuating unit) is applied. Brake tester switches off after wheels lock up (slip) or vehicle is pushed off the brake tester.
- Deactivate parking brake:
- Press button (1) and simultaneously press service brake pedal
NOTE: Duo-servo brake (actuating unit) is released. - Read off maximum brake power on left/right