Knock Sensor 2 fault code 00540 - PART No. FOR NEW FIXING BOLT???

My car is down on power (50bhp ish). A code reader flagged 'Knock Sensor 2', can anyone tell me anything about this and how its wired? Does it go direct to the ecu or is there a section of wire I can remove to inspect? I cant find anything relating to 05400 but found this in the Ross Tech Wiki Site

Thanks.

Also can I test the hall sender?

 

KNK 2 is on the side with cylinders 246. Maybe, related to the G40 (cam sensor hall), faulty or left disconnected/severed during the install. These do connect direct to ECU.
The hall sensor (G40) is in the dizzy. Test as per any 16v/8v 5v on "1", signal return on "0" and "3" sensor earth. Again maybe left disconneted or servered during install.

 

Thanks for the info. The exiter wire was severed during the install which points to the guy maybe being a bit rough.

Do you think this could cause such a great loss in power? The car feels OK to drive but quite flat, I have a graph from the R/R which shows a very flat curve which flattens further after 4000rpm. The operator said it was very lean from 4500rpm upwards.

He also mentioned a magnet that works with the hall sender which may have been put in the wrong way if the engine had been apart although I dont think it has, it was an 84000 mile replacement from a breakers yard for the original 138000 mile engine that was in it.

 

Should peak at around 3800-4500 depending on engine condition. Wait!! Yours is a coil pack version right?
Leaness will kill off any torque/power. But this maybe caused by other issues.

 

Yes, its OBD1 with coilpack.

The only error code it showed was Knock Sensor 2. I'll go and have a good look at it now.

This is a photo of the print out I was given:

 

It is on a Bosch Motronic 2.9 system. What people nickname as "OBD2" also comes as this system, albeit with difference software, then the last version was the system in mine Bosch M3.8.1. With the bosch identification you can correctly determine what system components and function would be running on the engine.
The hall sensor is on the right side of the coil pack on the upper timing chain cover. The test procedure for the hall dizzy is the same.

What is the 249bhp@5650rpm measurement about?
Where is the torque plot?

 

just checked autodata like you already know 00540 relates to the knock sensor but only suggests what you have already mentioned. its down to the sensor/wiring/ecm

 

at that dyno place they set the maximum measurable figure before each run, in this case that was 249bhp

no torque plots or AFR plots either

so the knock sensor could be on the bulkhead side of the block?

 

The 249 was Benny's mk1 20vt which had set the highest figure of the day untill Sambo and the AMG went on.

There were no tourqe plots.

I cant actually see the knock sensor but I think its behind the oil cooler pipes and this is nearest access to the the wiring:


So I can check that the knock sensor wires run like this:

Pin 1 to pin 57 on ECU plug (green/yellow)
Pin 2 to pin 33 on ECU plug (brown/white)
Pin 3 to pin 58 on ECU plug (black)

If I dont find a fault there will I have to remove the oil cooler to get at the knock sensor?

And the hall sender wires:

white/red to Pin 41 on the engine connection then pin 44 of the ECU plug
brown/black to Pin 42 on the engine connection then pin 58 of the ECU plug
black/yellow to earth.

Does that sound about right?

 

Depending on the orientation of the cooler it may have to at least be loosened a little. The knock sensor is bolted on to the block just to the right of where the water flow/return for the oil cooler goes into the block.

 

To my dismay, I only got 222 on the rollers, the 249 is the scale set for the graph as johnmk3 states. Funny too is that my graph also shows the 5650 revs - I don't know what that is? All in, the graphs don't actually say a lot! (a bit off topic there - soz)

 

Sounds good to me.

 

What size is the bolt on the knock sensor? Is it a 12mm or a rusty 13mm?

Any tips for removing it? I've took the slam panel off to access it but its tight as """", i've just bladdered it in WD40 for the minute.

 

Should be a 13mmAF.

Are you going to swap it with the one on bank 1 to see if the fault transfers?

 

I have got a working replacement to swap it for, so will give it a drive then re scan the codes.

 

The bolt was rounded so I invested in some Irwin Bolt Grip things and took it out in seconds!! First decent thing I've bought in ages!!

Does anyone know the part number for a replacement bolt of should I just visit my local bolt place and get a like for like replacement?

 

Vagcat says

N 0102336 :Hexagonal head bolt - M8 X28 / AAA,ABF 2E

 

This the one:

 

Cheers!! Did you find that on Vag Cat? I;ve been looking for ages but cant find it

 

Yep vagcat indeed

Been using it so much lately for VR6 parts for the mk2 i pretty much know where everything is now