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Knock sensor (178), Simtec: Connection

CONNECTOR PINOUTS REFERENCE

Pin No. Signal type Description
1 Signal High-ohm signal
2 Signal High-ohm signal
3 Ground Sensor's ground

The sensor listens to the working sound of the engine and converters it to electrical signals. ECM processes these signals via band pass filtering to differentiate the characteristic sounds made when the engine knocks. ECM listens in so-called "windows", i.e. for a certain number of crankshaft angles to differentiate knocks from normal (mechanical) background noises made while the engine is running. Knock control is individual to each cylinder and consists of retardation and fuel enrichment.

Fig 1: Circuit Diagram - Knock Sensor (178) (Simtec)
G03717996Courtesy of SAAB-SCANIA OF AMERICA, INC.