Gm Global Technolgoy Operations, Inc.

Daniel H Hooker

Chad W Lehner

Jeffrey M Polidan

Martin L Hall

Matthew J Roelle

Gary Edwin Johnston

Kevin E Person

A diagnostic system for a brake booster sensor includes a monitor that monitors a maximum error and a minimum error based on a brake booster sensor signal over a monitoring period. A first comparator determines one of a pass status and a fail status of the brake booster sensor based on the maximum error and the minimum error.

Brake booster vacuum sensor diagnostic

A diagnostic system according to the present invention diagnoses system failure of a secondary air injection system. The secondary air injection system includes a pump that provides air to an exhaust system via a conduit and a valve that controls the flow of air through the conduit. A pressure sensor measures pressure in the conduit. A controller predicts pressure in the conduit during first, second and third operational phases of the secondary air injection system. The controller compares the measured pressure to the predicted pressure to evaluate operation of the secondary air injection system. During the first phase, the secondary air injection system is used to reduce vehicle emissions. During the second phase, the valve is shut while the pump is on. During the third phase, the pump is turned off while the valve is closed.

Secondary air injection diagnostic system using pressure feedback

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Livonia, MI, United States of America

Daniel H Hooker