Chevrolet 10456287 Knock Sensor

Fluctuations in octane ratings in today's gasoline can ignite in the inside of an engine to cause detonation which is fondly referred to as "spark knock." The ESC (Electronic Spark Control) system is to use to retard spark by as much as 20 degrees to beat this spark knock, thus giving maximum spark advance for better dynamic response and fuel economy. The ESC knock sensor mounted on the engine block generates a voltage value of between 8 and 10 volts to the ECM when spark knock is not present to allow a normal advance. If the knock sensor ever records vibrations that are beyond the normal range of tolerance, the ESC module cuts the circuit to the ECM so that the voltage produced drops to zero volts and this signals the ECM to delay the timing until the problem causing spark knock is corrected. In the case where there is a failure either at the knock sensor signal or where there is no ground at the ESC module, the signal that reaches the ECM is always high, and that makes the ECM operate on the assumption that there is no spark knock present thus lead to severe spark knock while the engine is heavily loaded, often causing a Code 43. Further, if the ESC signal to the ECM is lost there will be a continual retardation of the EST, which will slow a car's performance as well as trigger a Code 43. To remove the ESC sensor, first disconnect the cable from the negative terminal of the block of battery, then disconnect the wiring harness from the sensor, and put out the screw on the block for the removal of the sensor, lastly, to fix the new sensor on the block of a battery the process will be reversed.