Knock Sensor Question
#1
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
Knock Sensor Question
Hey guys, simple question for you. Sorry if it's a really daft question, but I had a check engine light on thismorning and I plugged the laptop in and the fault recorded was the knock sensor. So does the check engine light coming on for the knock sensor mean there was knock detected? Or does it mean the actual knock sensor is faulty?
Last edited by simonds1; 29 June 2011 at 11:39 AM.
#2
Scooby Regular
iTrader: (1)
Hey guys, simple question for you. Sorry if it's a really daft question, but I had a check engine light on thismorning and I plugged the laptop in and the fault recorded was the knock sensor. So does the check engine light coming on for the knock sensor mean there was knock detected? Or does it mean the actual knock sensor is faulty?
#6
Scooby Regular
iTrader: (6)
and if ecu reset doesnt solve it, change it. not too bad to get at, wiggly socket & extension can get you onto it once the intercooler is removed. but just a bit fiddly!
id the same problem & changed mine, all good since. when refitting new one, try to get a washer the same size as the metal collar on top of the sensor so that when torquing up the bolt it rests on the washer and not the plastic which can cause it to crack again
the plastic cracks overtime and lets moisture in which gives the intermittent error.
correct torque for bolt is 23nm DO NOT OVERTIGHTEN
id the same problem & changed mine, all good since. when refitting new one, try to get a washer the same size as the metal collar on top of the sensor so that when torquing up the bolt it rests on the washer and not the plastic which can cause it to crack again
the plastic cracks overtime and lets moisture in which gives the intermittent error.
correct torque for bolt is 23nm DO NOT OVERTIGHTEN
#7
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
Thanks for all your responses guys Yeah the problem is intermittent - the check engine light just seems to randomly come on for a few seconds while I'm driving and then goes off again straight away. Thismorning it was coming on then going off.....then on again....then off....not in any sequence tho, it was just really random.....and that was all while I was idling before I'd driven anywhere! I thought surely it shouldn't be knocking then. Anyway, I'll keep an eye on it, I just don't wanna damage the engine obviously, cuz I know how catastrophic knock can be!
Trending Topics
#8
Somewhat annoyingly, there do seem to be a few cases where a faulty MAF sensor can cause the code 22 error. I don't know why this should happen but trustworthy, reliable people have reported it. Therefore, the fact that you are getting 22 adds to the suspicion. Although the first thing you should do in these circumstances is to check or replace the knock sensor.
You *can* check the knock sensor with a multimeter. Set it to resistance mode and see what you get across its two pins. The correct number should be 555Kohm +/- 5% or so. There should also be a direct connection (i.e. zero ohms) between the right hand pin as you look into the plug with the sensor upright, and the metal part of the sensor body. Be aware though that even if this sensor passes a static resistance test on a multimeter, it's still possible (albeit remotely) for it to be damaged. If you see any cracking in the plastic body, in particular, precautionary replacement is advisable.
You *can* check the knock sensor with a multimeter. Set it to resistance mode and see what you get across its two pins. The correct number should be 555Kohm +/- 5% or so. There should also be a direct connection (i.e. zero ohms) between the right hand pin as you look into the plug with the sensor upright, and the metal part of the sensor body. Be aware though that even if this sensor passes a static resistance test on a multimeter, it's still possible (albeit remotely) for it to be damaged. If you see any cracking in the plastic body, in particular, precautionary replacement is advisable.
#9
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
Hi guys, reviving an old thread here as I have finally got around to replacing my knock sensor because of having an intermittent & flickering check engine light coming on.....which was showing up on my laptop as Fault 22 knock sensor. Anyway, have replaced the knock sensor and now I have a constant check engine light that's on allllll the time. Doh! Here are my new & old knock sensors together......
My new one, even tho it has an identical part number (22060AA070), has got a yellow dot on it - see first picture. Does this mean anything? I know that there's a thing with a green stripe or dot meaning something on a MAF sensor? I was wondering does this yellow dot mean it's not compatible with my car for some reason? I just don't see how I can have fitted it wrong or why the light would now be on? Unless of course it's a dodgy sensor, it's possible I spoze. I have done an ecu reset and that hasn't got rid of it. Any ideas guys? I have a remap booked on 18th Nov so need to get it sorted before then.
Thanks in advance for your help
My new one, even tho it has an identical part number (22060AA070), has got a yellow dot on it - see first picture. Does this mean anything? I know that there's a thing with a green stripe or dot meaning something on a MAF sensor? I was wondering does this yellow dot mean it's not compatible with my car for some reason? I just don't see how I can have fitted it wrong or why the light would now be on? Unless of course it's a dodgy sensor, it's possible I spoze. I have done an ecu reset and that hasn't got rid of it. Any ideas guys? I have a remap booked on 18th Nov so need to get it sorted before then.
Thanks in advance for your help
Last edited by simonds1; 25 October 2011 at 11:11 AM.
#10
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
Started the car to come home from work tonight and there was no check engine light! I thought waheyyy it's solved......but then it came on about half way home and stayed on for the rest of the journey. Doh! I didn't use a torque wrench to fit the sensor, so would it throw up a constant check engine light if it was done up too tight/not tight enough?
#13
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
I did clean the mating surface yeah, as best I could in the fiddly gap! It's just the torque I'm worrying about now cuz we didn't use a torque wrench. My mate did the bolt up and he did it pretty tight I think, so I wonder if that's causing it? Does the doing up too tightly mean permanent damage to the sensor, or just that it won't be able to work properly?
#15
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
Hi Gambit. Thanks for this info, but I have just read on another website (subaru-impreza.org) that the correct torque is 24Nm? Ooh the joys of miss-leading information on the internet! How important is the torque? I don't really know if 1Nm is significant or not? Also, on the same website I've read that the "extraction area of the knock sensor cord must be positioned at a 60 degree angle relative to the engine rear"??? Has anyone ever heard of that before? I wouldn't have thought the mounting angle of a circular sensor would make a blind bit of difference?!
#18
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
Hi guys, just another quick question - does anybody know if there's a way I can test whether a knock sensor is actually working or not? Cuz it's obviously very annoying for me having to take my intercooler off (which I know is normally straight forward, but I've now got the much bigger STI8 intercooler on mine, it's a NIGHTMARE!!).....then fit a knock sensor.......then put the intercooler all back in nice.......then start the car to be greeted with a check engine light and an error code! Doh! Is the easiest way probably just to start the car with the knock sensor fitted before I put the intercooler back on etc? Just to see if the check engine light comes on?
#21
Scooby Regular
iTrader: (1)
Join Date: Sep 2011
Location: Herts/Essex
Posts: 311
Likes: 0
Received 0 Likes
on
0 Posts
Get the codes erased and get the ECU read/logged to see what is actually causing the light to come on.
#23
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
Yes it's definitely 110% the knock sensor bringing the light on I've done 2 ECU resets now and then next time I've started the car the light has come on again.......hook the laptop up and it's error 22 knock sensor every time. I'm gonna have a go at this now tomorrow anyway with my mate's torque wrench so I'll update then. I don't hold out much hope tho, cuz I'm really not convinced that the tightness of a bolt on a sensor could either make it work or not work? I have no idea! I could understand if I've tightened it up too much I might've actually broken it (DOH) but I can't see that loosening the bolt off to the right torque is gonna make it suddenly work. Ah well, only one way to find out isn't there!
#24
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
I just thought......nobody's said anything about the yellow dot question? If you look at one of the pics above you'll see that my new knock sensor has got a yellow dot marked on it and my original one didn't? Does this mean anything? Just don't wanna go through the effort of trying to sort this one and then someone say oh yeay by the way, the sensor with the yellow dot won't work on a MY00 car
#26
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
Right, update time. First of all I got my mate's torque wrench, got in there and re-fitted the bolt.....this time with the correct torque of 23Nm.....
On my way to doing this tho, I pulled at the knock sensor cable to move it out of the way and the wire just slipped out of the end of the plug as if it wasn't even connected......
So I thought that must've been the problem surely.......bad or no connection. So I chopped the plug apart a bit so I could secure the wire back on.....
The clamped it in with pliers and soldered it also for good measure.....
Then waterproofed it......
Tidy! Plugged it all back in tho, did an ECU reset, and it's made f*** all difference!......
I think I give up! I've done another ECU reset aswell just to make sure. Still the check engine light comes back on, and it's defo 110% the knock sensor. It must be a dodgy sensor surely. Gonna try sealing up the top of my old one and putting that back in to see if it's any better. Doh
On my way to doing this tho, I pulled at the knock sensor cable to move it out of the way and the wire just slipped out of the end of the plug as if it wasn't even connected......
So I thought that must've been the problem surely.......bad or no connection. So I chopped the plug apart a bit so I could secure the wire back on.....
The clamped it in with pliers and soldered it also for good measure.....
Then waterproofed it......
Tidy! Plugged it all back in tho, did an ECU reset, and it's made f*** all difference!......
I think I give up! I've done another ECU reset aswell just to make sure. Still the check engine light comes back on, and it's defo 110% the knock sensor. It must be a dodgy sensor surely. Gonna try sealing up the top of my old one and putting that back in to see if it's any better. Doh
#27
Scooby Regular
iTrader: (4)
Join Date: Sep 2009
Location: Bath
Posts: 930
Likes: 0
Received 0 Likes
on
0 Posts
ive read a few instances where the knock sensor cel code is logged on the ecu but its turned out to be a faulty maf,
suggest you have a search on here on knock sensor and also code 22 and read through the threads to see if you can find them.
ill have a look too now
suggest you have a search on here on knock sensor and also code 22 and read through the threads to see if you can find them.
ill have a look too now
#30
Scooby Regular
Thread Starter
Join Date: Nov 2006
Location: Pembrokeshire, South Wales
Posts: 639
Likes: 0
Received 1 Like
on
1 Post
read this one
https://www.scoobynet.com/general-te...ault-code.html
https://www.scoobynet.com/general-te...ault-code.html