Q: I ask a questiion earlier and was very pleased with response from Tim. After reading his answer i was browsing some of the other q

asked by on May 17, 2017

I wanted to comment while also asking if any of your mechanics have ever heard of this. I read where someone was asking about a knock sensor. I read an article and I quote "Believe it or not, some engineer at Toyota thought it was a good idea to disallow the vehehicle from changing into high gear if the knock sensor goes bad" Have you ever came across this situation and how would you know if the sensor is bad or just doing its job by not allowing the vehehicle to go into overdrive?

Hi Chris. I’ve always believed that engineers that design cars, trucks and SUV’s driving on the roads today are pretty smart folks, and contrary to what some might say, there is always a method to their madness. In the case of the knock sensor, if it is not able to diagnose engine issues on the fly, serious engine damage will eventually occur. When it fails, it triggers a limp mode (which is probably what the author of that quote was referencing). This article is actually a great one that talks about whether or not it is safe to drive with a damaged knock sensor that expands on why it’s smart for the vehicle to enter limp mode. In regards to how to tell if the knock sensor is doing it job or if it’s failing, this is where having a professional mechanic completing an OBD-II diagnostic inspection when symptoms occur is the best way to know for certain. Thanks for the reply.

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