DPB_a025_backupCircuitLeakage
DPB_a025_backupCircuitLeakage
Alert Information
Other
critical
<0.01%
Description
A leak or air in the backup hydraulic circuit is detected.
Potential Impact
Hyrdraulic pressure may drop during a leakage test. System will be running with internal degraded pedal map. Braking may require increased effort.
Set Condition
A leakage of brake fluid in the brake system: 1) Brake lines of wheel circuits FL, FR, RL, RR, 2) Output valves of wheel circuits FL, FR, RL, RR, 3) Low pressure seal of main brake cylinder 1 piston, 4) PSV valves of plunger. 5) Significant air in the brake system. An air in the brake system: - wheel circuits (incl. callippers) FL, FR, RL, RR, - main brake cylinder primary circuit (1), - main brake cylinder secondary circuit (2), - internal circuit below CSV, LEM evaluates pressure behaviour based on the active test sequence. The test sequence is executed in Postrun phase after a usual driving situation. Hereby the plunger provides a hydraulic pressure and stops. If pressure is dropping, then a leakage can be calculated. AIM evaluates pressure behaviour based on the active test sequence. If a combination of leakage and air is too high then the fault is set.
Clear Condition
No internal issue is detected after changing operation cycle. If the condition persists, the DPB module may require replacement.