US Patent:
20090064762, Mar 12, 2009
Inventors:
Robert J. Horner - Dexter MI, US
Craig M. Sawdon - Williamston MI, US
Thomas A. Szpakowski - South Lyon MI, US
Brian Carl Nelson - Bath MI, US
Karl T. Kiebel - Royal Oak MI, US
Marilyn L. Kindermann - Milford MI, US
Anthony L. Marks - Novi MI, US
International Classification:
G01L 23/22
Abstract:
A knock sensor diagnostic system may include a knock sensor. A bias circuit applies a bias voltage to the knock sensor. An input circuit receives an input signal based on the bias voltage. A control module indicates a short circuit associated with the knock sensor based on the input signal. A knock sensor diagnostic system may also or alternatively include a signal generator that generates and applies a test signal with a predetermined frequency to the knock sensor. Another input circuit receives another input signal that is based on the test signal. A control module indicates an open circuit associated with the knock sensor based on the other input signal.