Q: How to check and replace the knock sensor and Ignition Control Module for Chevrolet C1500 and K1500?
A: The knock sensor is liable for sensing irregular engine vibrations and minimizing spark knock. This results in a greater degree of AC output voltage, which is then given to ECM/PCM to retard the timing. Depending on the year and engine application, the location of this sensor can be different but normally it is found at the rear of the engine block or even at the side of cylinder head. For checking resistance of this sensor, remove electric connector and measure resistance between terminal and vital part of engine's body. If it falls outside this range, it should therefore be replaced. While running engine again, connect back connector and use voltmeter to verify an AC voltage signal here. Voltage ought to rise with increase in speed of an engine. If there is no any voltage signal available then knock sensor must be replaced because it has failed completely. When replacing this knock sensor just disconnect negative battery terminal before removing distributor or oil pressure sending unit if necessary; disconnect electrical connector and remove knocker from your engine block; installation is opposite to removal process. On 1988 -1995 models, ESC module located near throttle body however starting 1996 up to 2000 model years incorporated Knock Sensor Module with PCM as stated above; therefore remove PCM along with Knock Sensor Module cover also take out Knock Sensor by pinching retaining tabs & pulling up vertically straight; align tabs on notches press down until retaining clips snap into place for installing Knock Sensor Module while finally install PCM cover as well as Knock Sensor Module cover too.