NO BRAKING FORCE ASSISTANCE AFTER ENGINE START DIAGNOSTIC TROUBLE CODE (DTC) 4808B4. When starting the vehicle with Electric Park Brake (EPB) engaged. The brake pedal is hard. The red brake warning light in the instrument cluster lights up. The braking force assistance has failed (stiff brake pedal). Check Control message appears: Drive at a moderate speed. Braking force assistance. After starting the engine again the warning light is no longer active and the braking force assistance is available again.