Knock Sensor...you should read

Well i was reading the FSM and I ran into this paragraph that states:

Knock Sensor Malfunction
When the output signal of the knock sensor is
abnormal, the ECM judges it to be malfunctioning.
When knock sensor is malfunctioning, ignition
timing will retard according to operating
conditions.

Eek...I didnt think it did that, but you learn something
new everyday. So I rembered that back when I was
at the dealer a while ago, we put the consult on and
it pulled a knock sensor code (which is one of the codes
that does not trip a check engine light) and he cleared
it and told me not to worry about it.

Well...I have a JWT ECU so i really didnt feel like having
a stupid sensor retard my timing...so I called Jim and
he told me that their ECU will still perform that timing retarding
function, which is about 5 degrees back. Ouch.

Hmm...went down to the car and sure enough pulled a
code 34 which was the knock sensor. Went to the FSM
to see where that puppy was and wow...is it buried WAY
up there attached to the side of the engine. It is basically
right about underneath the intake manifold in the center of
the block. For this you need to jack the car up (jackstands
or garage with lift) and reach WAY up in the middle right
past the center support and exhaust.

Note: DEFINITELY let the car cool down alot before doing this.

The bolt is a 12mm and I tried every combination of socket/swivel
heads that you could think of, but there was too much crap around
it. So I finally took a 12mm wrench and managed to manuever my
hand up there enough to get just enough leverage to move that
tight bolt.

Note: There is only one wire running to the sensor...so dont
freak out like I did :)

Per the FSM, I used a multimeter to check the connectivity in Ohms
between the "A" connector on the knock sensor and a ground.
None...so I had a bad knock sensor.

So onto searching for a new part. Becuase this is a somewhat critical
part on the car I didnt want it giving false readings and potentially
sensing false knock. An aftermarket one probably would be ok, but
I didnt want to take the chance. I found one from Bosch for like $102,
but I opted for the Nissan one at $155. I guess if im spending that
much I might as well get the real deal. Especially cuz I didnt want to
have to go through the trouble of replacing one of those again.

Note: They usually dont stock these, so be prepared to wait a day...
or order one in advance if you think you need it.

So just something that you guys might all wanna check...becuase it
*does* affect your timing if it goes bad, but no check engine light,
only a code.

do you have a DET? just wondering cause you have a JWT ecu. :confused:

Nah ...no DET...i got the ECU pretty cheap to I decided to throw it in...i guess cuz i know im gonna use it later when i DO install the DET :)

Do you know what the torque specs are for the bolt?

knock sensor torque settings = 24 Nm or 18 lbf ft

word of warning, be very careful how you handle the unit, dropping its or a hard knock will damage it.