Knock Sensor info

4ca · Post by **4ca** » Fri Dec 30, 2005 3:54 pm

Hi guys,

What sort of signal is given by the knock sensor....? Is it a constant voltage? How does the signal change when it senses a ping?

Can I trick the ECU into thinking there is a knock sensor connected....(I know its not advised etc, just need the info)

Thanks in advance

Paul

fredsub · Post by **fredsub** » Fri Dec 30, 2005 10:58 pm

they are normally a capacitive microphone type of device, could put a 2nF capacitor across the leads, but I would expect that the ECU should normally adjust to it not being there if disconnected?
but what engine is this on?

4ca · Post by **4ca** » Sat Dec 31, 2005 11:07 pm

Sorry mate, should of mentioned that the engine is an EJ22 from a 96 lib.

How does the ECU interpret the 2nF capacitor? I basically have no idea but am keenly interested in how this works.

Thanks

fredsub · Post by **fredsub** » Sun Jan 01, 2006 7:40 am

I really don't think you need to 2nf cap, as the knock signal is AC, if you simply disconnect, the ECU's knock sensor won't hear anything

Is any fault code occuring with it disconnected? maybe the ECU can do a smart check, like check for any signal wilst engine is running.....if it does that, how to get around that? maybe a signal generator...but now its probably getting too complicated.....

4ca · Post by **4ca** » Sun Jan 01, 2006 11:14 pm

Hmmmm....

Outback bloke · Post by **Outback bloke** » Mon Jan 02, 2006 7:59 am

They do show a fault code with them disconnected. It is possible to simply mount them some where further away from the block but still on the engine.