knock sensors (pics) - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

josh_adnoh · 05-19-2009, 08:56 PM

ok first off all i did my research but i don't understand....i am new to this stuff so trying to figure this out....its been like a year that i got my s14 ka...and i started noticing these symptom's:

v-tec effect
loosing to an integra(aka: poor performance

bad gas mileage
misfiring

so i finally find out that it was my knock sensor i pulled my intake mani out of the way to get to it...now i have it in my hands

now i want to know if its my knock sensor that is bad or my wiring??
cause i know that allot of times its just a short or bad ground in the wiring??

there are little crack on the knock sensor but i read that doesn't mean there bad so i did a ohm test and this what came up

here is the fucked up sub harness is it suppose to be like that??

here is the other end that goes in the knock sensor

hopefully some one will help me and help others in the future

so
1: did i do the ohm test right
2:is it reading that i have a good or bad KS
3:is the sub harness suppose to be like that

I build motors all day · 05-19-2009, 08:59 PM

knock sensor sub harness goes from two wire to one at the end of the knck sensor.

I build motors all day · 05-19-2009, 09:00 PM

The factory spec is 500 - 620 Kohms.

I build motors all day · 05-19-2009, 09:02 PM

how sure are your knock sensor is bad if there is no DTC's from the ecu. and just test the harness for continuity

josh_adnoh · 05-19-2009, 09:05 PM

sorry it was throwing the code 34 wich is knock sensor...and ill try the harness

josh_adnoh · 05-19-2009, 09:15 PM

no the black wire isn't touching the yellow one cause you see at the pic of the sub-Harness where it connects it just hanging there...so your saying that the black one i suppose to touch the yellow one right???

96Turbo · 05-20-2009, 01:35 PM

the reason there are 2 wires going into 1 is because it's a shielded wire. the outter wire wrapped around the inside is a ground wire...it's supposed to be like that

however, i'm having the same problem with my KS system (code 34). I plan on checking:

resistance of the sensors (like you've already done & compare to the value listed in the FSM)

checking the KS harness for continuity (from ECU to sensor...this is where i think my problem lies)

good luck and let me know what you do to fix it!

Killa_D · 05-20-2009, 01:40 PM

just go and buy a new subharness and sensor and call it a day.

96Turbo · 05-20-2009, 01:54 PM

^^why do that when you can fix the harness for free and we've already concluded his sensor is good??

blackej7 · 05-20-2009, 03:30 PM

Actually, my knock sensor ohm'd out within spec, the wiring was good, and i would still intermittently throw a code 34.

I replaced the knock sensor and the code hasn't come back. Sensors do go bad eventually.

josh_adnoh · 05-20-2009, 07:54 PM

got another used but better condition KS with sub harness and i think i know what was wrong....you guys know the ground the closest to the fire wall on the driver side of the engine,its in the same harness as the front o2...well that ground wasn't grounded,it was just haging at the back of my motor?

RPSil13 · 05-21-2009, 09:09 AM

can someone show me where the know sensor is located
thanks

Nezahualcoyotl · 05-21-2009, 09:27 AM

lol its tucked under the intake manifold...
not my motor

http://www.brandonwoods.net/240sx/im...ock_sensor.jpg

96Turbo · 05-21-2009, 10:39 AM

nice lookin engine bay man. Is that a datsun or somethin? pretty cramped in there

...........loooks like my RB in the 240...

Do you have some pusher radiator fans? or are you fanless? how is that working for ya?

josh_adnoh · 05-21-2009, 11:22 AM

Quote:

Originally Posted by 96Turbo

nice lookin engine bay man. Is that a datsun or somethin? pretty cramped in there

...........loooks like my RB in the 240...

Do you have some pusher radiator fans? or are you fanless? how is that working for ya?

sorry for the confusion but this is not my motor....just took that pic of google to show the ground...but i agree its a nice looking motor..and im not quite sure how the cooling setup is done there???

josh_adnoh · 05-21-2009, 11:31 AM

Quote:

Originally Posted by Killa_D

just go and buy a new subharness and sensor and call it a day.

well that is what i have done....i double checked all my wires from ecu to KS...so no need for new wires and i just ordered a brand new genuine nissan KS from ebay...cost me 100$ with shipping....now i need a crank position sensor to turn my engine light off...any body got a good working one for sale???thanks josh

all stock · 05-21-2009, 11:46 PM

altho it's rare, make sure to rule out the ECU too.

kcvpr · 05-22-2009, 06:38 AM

You can just bypass it with a 1,000ohm resistor...

There is a tan wire coming out of the ecu, that's the knock sensor signal wire. Just cut that (or put crimp on plug connectors so you can switch back) attach the resistor to the the tan wire, and then ground the resistor to something....

Or you could do it like this guy did :

http://wiki.answers.com/Q/Can_you_by...nsor_if_so_how

96Turbo · 05-22-2009, 11:17 AM

^^I don't see why you would ever want to do that unless you're completely broke and don't give a fuck if your engine lasts another week or not. If this is a turbo motor then the KS is a VITAL part of the ecu control system....

I would like my ECU to prevent my engine from blowing itself up when it starts knocking...but that's just me

josh_adnoh · 05-22-2009, 02:55 PM

Quote:

Originally Posted by all stock

altho it's rare, make sure to rule out the ECU too.

how can i check the ecu if i can???....and if its still running like crap after,and still getting code 34...then ill know its the ecu

josh_adnoh · 06-07-2009, 10:05 PM

well all together now and running,no 34 code,doesn't feel like its doing the v-tec but only took for a quick drive...will post if something happens...thanks alot

ttLOVEjh s13 · 07-11-2009, 07:20 PM

Man I got almost the same problem as you JOSH.. but my car runs fine, tested and everything, just that damn knock sensor code pops up everytime i reset it after 2 to 3 days. think it might be the sensor too on my car...? what do you guys think....?

please pm me thanks....

UNISA JECS · 07-11-2009, 07:23 PM

9/10 its never a bad knock sensor, its a short to ground in the shielded signal wire (very hard to find).

slideways2004 · 07-11-2009, 09:50 PM

I have a brand new oem knock sensor if anybody needs it. Just send me a pm

96Turbo · 07-12-2009, 09:09 PM

Quote:

Originally Posted by UNISA JECS

9/10 its never a bad knock sensor, its a short to ground in the shielded signal wire (very hard to find).

truf. mine was

Om1kron · 07-13-2009, 01:25 AM

Quote:

Originally Posted by 96Turbo

I would like my ECU to prevent my engine from blowing itself up when it starts knocking...but that's just me

last I read knock sensor does not detect knock, it's only purpose is to pull timing. and stiffened mounts can cause them to fuck up.

Autobacs · 07-13-2009, 07:31 AM

Quote:

Originally Posted by Om1kron

last I read knock sensor does not detect knock, it's only purpose is to pull timing. and stiffened mounts can cause them to fuck up.

Yes it does detect knock and then retards timing.

It is not foolproof though and it can interpret other engine/car noises as engine knock.

Kaifd3s · 07-26-2009, 07:45 PM

anyone have a diagram of the wiring from the ECU to the subharness?

05-19-2009, 08:56 PM	#1
josh_adnoh Leaky Injector Join Date: Apr 2008 Location: nb,canada Posts: 53 Trader Rating: (2) Feedback Score: 2 reviews	knock sensors (pics) ok first off all i did my research but i don't understand....i am new to this stuff so trying to figure this out....its been like a year that i got my s14 ka...and i started noticing these symptom's: v-tec effect loosing to an integra(aka: poor performance bad gas mileage misfiring so i finally find out that it was my knock sensor i pulled my intake mani out of the way to get to it...now i have it in my hands now i want to know if its my knock sensor that is bad or my wiring?? cause i know that allot of times its just a short or bad ground in the wiring?? there are little crack on the knock sensor but i read that doesn't mean there bad so i did a ohm test and this what came up here is the fucked up sub harness is it suppose to be like that?? here is the other end that goes in the knock sensor hopefully some one will help me and help others in the future so 1: did i do the ohm test right 2:is it reading that i have a good or bad KS 3:is the sub harness suppose to be like that

05-20-2009, 03:30 PM	#10
blackej7 Zilvia Junkie Join Date: Jul 2006 Location: Midwest Posts: 324 Trader Rating: (9) Feedback Score: 9 reviews	Actually, my knock sensor ohm'd out within spec, the wiring was good, and i would still intermittently throw a code 34. I replaced the knock sensor and the code hasn't come back. Sensors do go bad eventually. __________________

05-20-2009, 07:54 PM	#11
josh_adnoh Leaky Injector Join Date: Apr 2008 Location: nb,canada Posts: 53 Trader Rating: (2) Feedback Score: 2 reviews	got another used but better condition KS with sub harness and i think i know what was wrong....you guys know the ground the closest to the fire wall on the driver side of the engine,its in the same harness as the front o2...well that ground wasn't grounded,it was just haging at the back of my motor? Last edited by josh_adnoh; 05-20-2009 at 09:41 PM..

05-21-2009, 11:46 PM	#17
all stock Zilvia Junkie Join Date: Oct 2003 Location: Irvine Posts: 312 Trader Rating: (0) Feedback Score: 0 reviews	altho it's rare, make sure to rule out the ECU too. __________________ NASA PTD/SCCA ITS

07-11-2009, 07:20 PM	#22
ttLOVEjh s13 Zilvia Addict Join Date: Sep 2008 Location: (714) Age: 36 Posts: 920 Trader Rating: (14) Feedback Score: 14 reviews	Man I got almost the same problem as you JOSH.. but my car runs fine, tested and everything, just that damn knock sensor code pops up everytime i reset it after 2 to 3 days. think it might be the sensor too on my car...? what do you guys think....? please pm me thanks.... __________________ GamerTag:JHLOVETT ABS?? We dont need ABS where we'er going

05-19-2009, 08:59 PM	#2
I build motors all day Zilvia Member Join Date: May 2009 Location: Chino Hills Posts: 194 Trader Rating: (7) Feedback Score: 7 reviews	knock sensor sub harness goes from two wire to one at the end of the knck sensor.

05-19-2009, 09:00 PM	#3
I build motors all day Zilvia Member Join Date: May 2009 Location: Chino Hills Posts: 194 Trader Rating: (7) Feedback Score: 7 reviews	The factory spec is 500 - 620 Kohms.

05-19-2009, 09:02 PM	#4
I build motors all day Zilvia Member Join Date: May 2009 Location: Chino Hills Posts: 194 Trader Rating: (7) Feedback Score: 7 reviews	how sure are your knock sensor is bad if there is no DTC's from the ecu. and just test the harness for continuity

05-19-2009, 09:05 PM	#5
josh_adnoh Leaky Injector Join Date: Apr 2008 Location: nb,canada Posts: 53 Trader Rating: (2) Feedback Score: 2 reviews	sorry it was throwing the code 34 wich is knock sensor...and ill try the harness

05-19-2009, 09:15 PM	#6
josh_adnoh Leaky Injector Join Date: Apr 2008 Location: nb,canada Posts: 53 Trader Rating: (2) Feedback Score: 2 reviews	no the black wire isn't touching the yellow one cause you see at the pic of the sub-Harness where it connects it just hanging there...so your saying that the black one i suppose to touch the yellow one right???

05-20-2009, 01:35 PM	#7
96Turbo Zilvia FREAK! Join Date: Nov 2007 Location: AZ Age: 35 Posts: 1,315 Trader Rating: (11) Feedback Score: 11 reviews	the reason there are 2 wires going into 1 is because it's a shielded wire. the outter wire wrapped around the inside is a ground wire...it's supposed to be like that however, i'm having the same problem with my KS system (code 34). I plan on checking: resistance of the sensors (like you've already done & compare to the value listed in the FSM) checking the KS harness for continuity (from ECU to sensor...this is where i think my problem lies) good luck and let me know what you do to fix it!

05-20-2009, 01:40 PM	#8
Killa_D Zilvia FREAK! Join Date: Nov 2006 Location: nowhere Posts: 1,463 Trader Rating: (39) Feedback Score: 39 reviews	just go and buy a new subharness and sensor and call it a day.

05-20-2009, 01:54 PM	#9
96Turbo Zilvia FREAK! Join Date: Nov 2007 Location: AZ Age: 35 Posts: 1,315 Trader Rating: (11) Feedback Score: 11 reviews	^^why do that when you can fix the harness for free and we've already concluded his sensor is good??

05-21-2009, 09:09 AM	#12
RPSil13 Zilvia FREAK! Join Date: Aug 2006 Location: OC/SoCal Posts: 1,108 Trader Rating: (17) Feedback Score: 17 reviews	can someone show me where the know sensor is located thanks

05-21-2009, 09:27 AM	#13
Nezahualcoyotl Zilvia Addict Join Date: Oct 2006 Location: Santa Ana, California Age: 37 Posts: 769 Trader Rating: (16) Feedback Score: 16 reviews	lol its tucked under the intake manifold... not my motor http://www.brandonwoods.net/240sx/im...ock_sensor.jpg

05-21-2009, 10:39 AM	#14
96Turbo Zilvia FREAK! Join Date: Nov 2007 Location: AZ Age: 35 Posts: 1,315 Trader Rating: (11) Feedback Score: 11 reviews	nice lookin engine bay man. Is that a datsun or somethin? pretty cramped in there ...........loooks like my RB in the 240... Do you have some pusher radiator fans? or are you fanless? how is that working for ya?

05-22-2009, 06:38 AM	#18
kcvpr Join Date: Jan 2009 Location: Vacaville CA Posts: 49 Trader Rating: (0) Feedback Score: 0 reviews	You can just bypass it with a 1,000ohm resistor... There is a tan wire coming out of the ecu, that's the knock sensor signal wire. Just cut that (or put crimp on plug connectors so you can switch back) attach the resistor to the the tan wire, and then ground the resistor to something.... Or you could do it like this guy did : http://wiki.answers.com/Q/Can_you_by...nsor_if_so_how

05-22-2009, 11:17 AM	#19
96Turbo Zilvia FREAK! Join Date: Nov 2007 Location: AZ Age: 35 Posts: 1,315 Trader Rating: (11) Feedback Score: 11 reviews	^^I don't see why you would ever want to do that unless you're completely broke and don't give a fuck if your engine lasts another week or not. If this is a turbo motor then the KS is a VITAL part of the ecu control system.... I would like my ECU to prevent my engine from blowing itself up when it starts knocking...but that's just me

06-07-2009, 10:05 PM	#21
josh_adnoh Leaky Injector Join Date: Apr 2008 Location: nb,canada Posts: 53 Trader Rating: (2) Feedback Score: 2 reviews	well all together now and running,no 34 code,doesn't feel like its doing the v-tec but only took for a quick drive...will post if something happens...thanks alot

07-11-2009, 07:23 PM	#23
UNISA JECS Nissanaholic! Join Date: Feb 2007 Location: Socal Fontana Age: 45 Posts: 2,380 Trader Rating: (40) Feedback Score: 40 reviews	9/10 its never a bad knock sensor, its a short to ground in the shielded signal wire (very hard to find). __________________ PARTS 4 SALE !! Z32 E-Brake/Parking Brake Heatshield Assemblys!!! *Rep/Feedbacks*

07-11-2009, 09:50 PM	#24
slideways2004 Nissanaholic! Join Date: Apr 2005 Location: Houston Age: 37 Posts: 1,706 Trader Rating: (6) Feedback Score: 6 reviews	I have a brand new oem knock sensor if anybody needs it. Just send me a pm

07-26-2009, 07:45 PM	#28
Kaifd3s Zilvia Addict Join Date: Feb 2008 Location: Tamarac, Florida Age: 38 Posts: 694 Trader Rating: (16) Feedback Score: 16 reviews	anyone have a diagram of the wiring from the ECU to the subharness? __________________