HELP!! knock sensor voltage?

[Damo]

Do's anyone know what voltage i should have at the knock sensor plug?

Is it just battery voltage or do's it vary depending on engine speed.

Ive tested mine as ive a code 16 saying knock sensor no change in voltage ive tested the wiring but i hve no reading at all at the plug or at the 5 pin plug to the mini loom going to the knock sensor.

Also do's anyone know the pin numbers that power the knock sensor form the ecu think the pulse is pin 11 but dont know the other wire pin if anyone knows this could be a big help if i need to rewire it.

Or would it just be easier to fit another loom?

anyways any help is muchos appreciated and as allways rep on offer for any good replys.

Damo.

[John]

Iirc it shouldn't be battery voltage as it's only a signal wire. Have you had it on tech1 (or similar) to check the knock whilst it's running?

[Damo]

Iirc it shouldn't be battery voltage as it's only a signal wire. Have you had it on tech1 (or similar) to check the knock whilst it's running?

No john just run faults off ecu read on another forum that its a common fault on XE's that when you get a code 16 its normally a broken wire in the loom?
I dont know alot about XE's tbh but ive changed the sensor 3 times and im still getting the same code up even after resetting the ecu so im just assuming its a broken wire as im getting no voltage at all down there but then again am i supposed to get a reading or does it just send a signal as and when?

Damo.

[John]

It alters the timing as it detects "knock" If you've tried 3 sensors then i'm guessing it won't be that. How does it run? U have another loom you can try?

[Damo]

It alters the timing as it detects "knock" If you've tried 3 sensors then i'm guessing it won't be that. How does it run? U have another loom you can try?

It runs spot on john up untill around 3000rpm then it sends the ecu light on an becomes very limp and down on power but anything under 3000rpm its spot on. No i dont have a spare loom either i was gonna buy one but was hoping that it was something id done wrong lol.

[Balley]

Most are 5v some are only one volt... if its all good then the voltage should go up and down as it only makes a voltage when the engine 'knocks'

Are you having troubles with preignition?

[Damo]

Most are 5v some are only one volt... if its all good then the voltage should go up and down as it only makes a voltage when the engine 'knocks'

Are you having troubles with preignition?

The only probs ive got is at 3000rpm mate when it sends the ecu light on other than being a bit stuttery some sometimes it seems fine plenty of power up till said point too!!

[Balley]

you tryed the coil?

[craig green]

I hope you arent tightening these knock sensors on, they only need to be hand tight. Using a wrench will easily allow you to overtighten it, its a fragile sensor.

Wiring to the sensor would be my guess though, its not mixed up with the idle valve (ICV) connector is it?

[Damo]

I hope you arent tightening these knock sensors on, they only need to be hand tight. Using a wrench will easily allow you to overtighten it, its a fragile sensor.

Wiring to the sensor would be my guess though, its not mixed up with the idle valve (ICV) connector is it?

No mate torqued to 20nm on all of them i didnt know weather it should have a voltage reading direct to it or weather it sent a reading as an when as i said in an earlier post i put a volt meter across the terminals and ive got nothing at all even when revving it and ive got the plugs the right way too red to knock etc....:confused:

[Damo]

Right just read on clubcalibra that the knock sensors dont receive a voltage from the ecu they send a voltage signal as and when required is this right as that would explain why im not getting a voltage reading from the plug when testing it?

[Stuart]

iirc 5Nm rings a bell for knock torque

[craig green]

iirc 5Nm rings a bell for knock torque

mmm its not even worth using a wrench, just wind it home nicely so it wont rattle out.

Not sure how the sensor would 'send' a voltage, surely the ECU is looking for some kind of resistance in the wires?

[Damo]

mmm its not even worth using a wrench, just wind it home nicely so it wont rattle out.

Not sure how the sensor would 'send' a voltage, surely the ECU is looking for some kind of resistance in the wires?

There again on the clubcalibra site there saying torque them to 20nm :( appararently theres a crystal inside them and this creates a voltage and sends it back to the ecu but dont know how true this is though.

[comptoncj]

Still having problems then chap? Ive decided to throw away the loom that came with my engine and re loom it lol ive had enough of p**sing about with it. So what does yours do? runs fine until you go over 3000revs? and then stutters or just tries to cut out?

[Damo]

Yea mate still having problems it dosnt cut out or owt it throws the managment light on at 3000rpm but then continues to run but really down on power. Ive read up a bit on different webpages and people have had the same problem but it ended up being the wireing to the ecu so im starting to think that ive got the same problem and am gonna change the loom. They have said to change the wire but i may be as well just getting a good loom i think so the jobs done right.

[comptoncj]

Finding a broken wire on the loom in situ wont be easy, I dont know whats going on with mine, it overfuels cam sensor codes coming up and now wont start juts floods itself lol so I just thought couple of hours to change the loom and all the engine sensors is probs worth it.

[Damo]

Finding a broken wire on the loom in situ wont be easy, I dont know whats going on with mine, it overfuels cam sensor codes coming up and now wont start juts floods itself lol so I just thought couple of hours to change the loom and all the engine sensors is probs worth it.

Have you tried another fuel pressure reg? sound like something an nothing with yours tbh also the cam sensor on your engine will be the hall sensor on the dissy is the dissy a good one? but if all else fails like you said for the messing around a couple of hours work changeing the loom is nowt tbh.

[comptoncj]

Im picking up another 20xe off the Count today so when thats home first thing im going to do is swap the rail over, AFM, Dizzy lol

[Damo]

Im picking up another 20xe off the Count today so when thats home first thing im going to do is swap the rail over, AFM, Dizzy lol

Yea thats what id be inclined to do first mate before choping the loom out lol you never know may be a simple fix.

[comptoncj]

Hmm just took the loom out in 10 mins lol i wasnt getting battery voltage at the dizzy and theres loads of wires that are about to go brittle and break so i though meh de-loom it lol just gonna change all the managment over if that doesnt sort it il burn it lol

[Damo]

Hmm just took the loom out in 10 mins lol i wasnt getting battery voltage at the dizzy and theres loads of wires that are about to go brittle and break so i though meh de-loom it lol just gonna change all the managment over if that doesnt sort it il burn it lol

Lol i like well when you put it that way then prob best to reloom it then mate.

[Damo]

Sorted the problem did a resistance test on the wires today ground was fine but the pulse wire form pin 11 was dead so i ran a new wire to the connecting block under the tank vent and hey presto problem solved no ecu light at all.

Happy days.:thumb: