Test sequence for brake system

A method of testing a braking system for an automotive vehicle that includes a brake booster, a first brake assembly associated with a first wheel of the automotive vehicle, a second brake assembly associated with a second wheel of the automotive vehicle, a third brake assembly associated with a third wheel of the motor vehicle, and a fourth brake assembly associated with a fourth wheel of the automotive vehicle, a first inlet valve adapted to selectively allow flow of brake fluid to the first brake assembly, a second inlet valve adapted to selectively allow flow of brake fluid to the second brake assembly, a third inlet valve adapted to selectively allow flow of brake fluid to the third brake assembly, and a fourth inlet valve adapted to selectively allow flow of brake fluid to the fourth brake assembly, a first outlet valve adapted to selectively allow brake fluid to flow from the first brake assembly to a brake fluid reservoir, a second outlet valve adapted to selectively allow flow of brake fluid from the second brake assembly to the brake fluid reservoir, a third outlet valve adapted to selectively allow flow of brake fluid from the third brake assembly to the brake fluid reservoir, and a fourth outlet valve adapted to selectively allow brake fluid to flow from the fourth brake assembly to the brake fluid reservoir, the method comprising:

• sequentially and alternately testing one of the first inlet valve and the first outlet valve, the second inlet valve and the second outlet valve, the third inlet valve and the third outlet valve and the fourth inlet valve and the fourth outlet valve upon consecutive occurrences of an operational event of the automotive vehicle;
• and
• sending diagnostic information to a controller within the automotive vehicle each time one of the first inlet valve and the first outlet valve, the second inlet valve and the second outlet valve, the third inlet valve and the third outlet valve and the fourth inlet valve and the fourth outlet valve is tested.

A method of testing a braking system for an automotive vehicle comprising:

• upon consecutive occurrences of an operational event of the automotive vehicle sequentially and alternately testing one of a first inlet valve and a first outlet valve that are associated with a first wheel and first brake assembly, a second inlet valve and a second outlet valve that are associated with a second wheel and a second brake assembly, a third inlet valve and a third outlet valve that are associated with a third wheel and a third brake assembly, and a fourth inlet valve and a fourth outlet valve that are associated with a fourth wheel and a fourth brake, wherein testing one of the first inlet valve and the first outlet valve, the second inlet valve and the second outlet valve, the third inlet valve and the third outlet valve and the fourth inlet valve and the fourth outlet valve further includes:
• closing the first, second, third and fourth inlet valves;
• actuating a brake booster and increasing the pressure of brake fluid between the brake booster and the first, second, third and fourth inlet valves to a pre-determined Boost Pressure;
• measuring a first plunger volume of the brake booster;
• actuating one of the first, second, third and fourth inlet valves to an open position;
• actuating the brake booster and increasing the pressure of brake fluid between the brake booster and the first, second, third and fourth inlet valves to the pre-determined Boost Pressure;
• measuring a second plunger volume of the brake booster;
• and
• when the difference between the first and second plunger volume exceeds an Expected Difference Threshold, sending diagnostic information that the actuated one of the first, second, third and fourth inlet valves has not failed to the controller within the automotive vehicle;
• and
• when the difference between the first and second plunger volume does not exceed the Expected Difference Threshold, and when the first plunger volume exceeds a Fail Open Threshold, sending diagnostic information that the actuated one of the first, second, third and fourth inlet valves has failed to an open state to the controller within the automotive vehicle;
• and
• when the difference between the first and second plunger volume does not exceed the Expected Difference Threshold, and when the first plunger volume does not exceed the Fail Open Threshold, sending diagnostic information that the actuated one of the first, second, third and fourth inlet valves has failed to a closed state to the controller within the automotive vehicle.