Patent ID: 11951960
Assignee: ZF ACTIVE SAFETY US INC.
Field: Transport (Mechanical engineering)
Classification: CPC B  G | IPC B  G

Claim 0:
1. A diagnostic method for a vehicle brake system to identify a leak in at least one three-way valve comprising the steps of:
moving a plunger in a plunger assembly to a home/retracted position;
energizing a pumping valve while de-energizing a primary and a secondary three-way valve together with a plurality of apply valves and dump valves;
applying pressure to a plurality of conduits between the plunger assembly and a group of components comprising the secondary three-way valve, the primary three-way valve and a replenishing check valve so that a pre-determined pressure is achieved;
holding the plunger in position within the plunger assembly while monitoring pressure at a boost pressure sensor to determine the rate of pressure decay; and
identifying a leak in at least one of the primary and secondary three-way valves.