Knock Sensor Operation

Knock Sensor Operation Amazon Printed Books Amazon Kindle Edition Android APPs Explains the Knock Sensor Operation and Testing. The Knock sensor is a actual microphone screwed into the engine block. It is tuned to listen to the exact frequency of an engine knock, which is a high frequency ping. A failing knock sensor will cause all sorts of problems to engine operation, such as skewed timing controls, loss of performance and power and ever the system going to linp-in mode. Learn how it works and how to test this incredible component. (note: We allow all schools and training institutions to use our software free of charge, so long as it is not sold to others. You're encouraged to download our free automotive simulation software for more information. ************************************************************************************** Amazon Printed-Books & Kindle: Google Play Android APPs: Amazon Video DVDs: Barnes & Noble Nook: Apple iTunes iPad:

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Knock Sensor Quick-Fix
SOFTWARE CATALOG: Knock Sensor Quick-Fix The knock sensor is used by the ECM to fine tune ignition timing. A faulty knock sensor will cause a faulty code to set, and may also cause ignition timing to be skewed. Lack of power may also be another symptom. These are the knock sensor facts. 1) The knock sensor is a type of microphone, screwed to the engine block or manifold. 2) It is a piezo electric or crystal component. 3) Knock sensors produce their own electricity. 4) A knock sensor produces alternating or AC current. 5) The sensor is tuned to between 6 to 9 thousand Hertz, which is the pinging frequency, so as not to confuse the ECM. 6) There are two types of knock sensors, the older wide band, and the newer resonant or tuned knock sensor. 7) You test these two types of sensors differently. 8) To test the wide band knock sensor, with engine and key off, probe with a volt meter set to AC, between battery ground and the knock sensor signal wire. Then, light tap near the knock sensor using an extension or back of the ratchet wrench. 9) The resonant newer style knock sensor will not react to engine tap. These sensors are tuned only to an engine ping. 10) To test these sensors, connect the volt meter as before, start the engine, then remove the fuel pump relay or fuse. As the vehicle is starved for fuel, pre-load the engine a bit by putting the car in gear, foot on brake, and accelerate a bit. The fuel starved engine will ping. On both tests you should see an AC voltage outputted. That concludes the knock sensor Quick-Fix.

Tip Clip: Knock Sensor Testing
Dave Scaler from MEA presents testing tips on the most popular import models your customers drive today. Learn quick & surefire ways to diagnose and fix the toughest problems in this growing portion of your repair business. Check it out at

knock sensor bypass
I installed new head gaskets on my Toyota 3.0 / 3VZE and spaced changing the knock sensor (although it had not issues prior to dis-assembly). After completing the project and driving the 4-runner, the check engine light came on and I was stuck with this code. In researching the code to determine what I needed to do to resolve the problem I found that simply unplugging the sensor and leaving it for a short time had been known to cause issues and require a sensor replacement. Apparently that is standard procedure in many shops when doing head gaskets on this engine. That being said, I researched to find a way around pulling the engine back apart. What I found was someone had done some research and claimed that the displacement of this 3VZE engine was similar to a Chevy S10 4cyl and that the knock sensor was compatible. There was some controversy about the sensor being located in a bad spot and that inevitably there would be engine damage. I decided to give it a shot. It has now been 6 months, no engine light, no knocking, 16 - 19 mpg, I am happy. Thanks for watching.

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