Knock Sensor - Subaru Enthusiasts Car Club of the Sierras

coronan · 2007-01-02, 08:25 PM

Hey I'm probably going to catch major hell for a stupid question. But...

Im trying to get rid of a knock sensor fault code.

Can somone verify that this is the knock sensor on a EJ25? Ive checked it with a mulitmeter and ther's no continuity but I want to make sure I'm checking the right thing.

Have a Sweet Day!

sperry · 2007-01-02, 08:55 PM

I can't say I've ever found my knock sensor... but you can check here for the service manuals:

http://www.seccs.org/tech/

khail19 · 2007-01-02, 09:35 PM

Where's Cory when you need him?

MattR · 2007-01-02, 09:50 PM

Quote:

Originally Posted by khail19

Where's Cory when you need him?

At Joe Bob's eating chicken.

khail19 · 2007-01-02, 09:56 PM

Damn him and his need to fit the stereotype.

sybir · 2007-01-02, 10:17 PM

That looks like it, but it's hard to tell becuase of the various parts that look like they're loose (I can't locate it effectively). I've got an EJ25 too, but my throttle cable doesn't run perpendicular like that....

I beleive the knock sensor is behind the manifold and on the right side of center when looking into the engine bay from the front, and that definitely lookslike it (a single bolt runs through it and into the block). Additionally, that connector looks like the right one.

Sorry I can't be of more help, I got lazy and had the shop I was working for at the time fix it when mine went.

coronan · 2007-01-02, 10:58 PM

Ok Im gaining conficence. I folded the throttle body out of the way to gain access to the connector. Yes its under the throttle body pullies, behind the intake manifold, right of center on the top of the block. You can see the hydraulic clutch to the rear.

So then the manual says if it does not have continuity the unit is working. It DOES NOT. What are the other common causes for this sensor to trip???

I installed an underdrive pully about a week before the check engine light first showed up. If reset the light comes back in 3 or 4 days.

I'm sporting 110,000 miles but the motor sounds good and hasnt exhibited any loss in power.

Any experience, Anyone???

sperry · 2007-01-03, 06:54 AM

Quote:

Originally Posted by coronan

Ok Im gaining conficence. I folded the throttle body out of the way to gain access to the connector. Yes its under the throttle body pullies, behind the intake manifold, right of center on the top of the block. You can see the hydraulic clutch to the rear.

So then the manual says if it does not have continuity the unit is working. It DOES NOT. What are the other common causes for this sensor to trip???

I installed an underdrive pully about a week before the check engine light first showed up. If reset the light comes back in 3 or 4 days.

I'm sporting 110,000 miles but the motor sounds good and hasnt exhibited any loss in power.

Any experience, Anyone???

Since the knock sensor is really just a microphone that's listening for the sounds of pre-detonation, there is a chance that there's simply something making a similar noise and triggering the knock sensor. Did anything get loosened when you did the pulley swap that might be banging on the block under vibration?

MPREZIV · 2007-01-03, 07:29 AM

That part circled in the picture, is 100% for sure the knock sensor!

And I wasn't eating chicken... we had spaghetti for dinner last night.

sperry · 2007-01-03, 07:31 AM

Quote:

Originally Posted by MPREZIV

That part circled in the picture, is 100% for sure the knock sensor!

And I wasn't eating chicken... we had spaghetti for dinner last night.

Damn, I didn't know you could fry spaghetti!

MPREZIV · 2007-01-03, 07:42 AM

You've never been down south... you can deep fry ANYTHING!!!!

That knock sensor is supposed to have a resistance from one of the two pins to the inside of the housing where the bolt goes through, once you remove it from the block. I don't recall what pin, or what the resistance spec. is tho. Lemme look through some svc. manuals I have, and get back to you.

Oh, and the knock sensor is the ONLY code you're getting? Most of the time they won't actually turn on the CEL...

MPREZIV · 2007-01-03, 08:16 AM

I looked in Alldata, but I couldn't find anything on spec. or which pin is which. I *do* know that there is supposed to be continuity between one of the connector pins, and the metal inner body of the sensor.

AtomicLabMonkey · 2007-01-03, 10:24 AM

Quote:

Originally Posted by MPREZIV

You've never been down south... you can deep fry ANYTHING!!!!

I can verify this.

2007-01-02, 08:25 PM	#1
coronan n00b Join Date: Nov 2006 Location: Reno Posts: 9 Car: 99 OBW	Knock Sensor Hey I'm probably going to catch major hell for a stupid question. But... Im trying to get rid of a knock sensor fault code. Can somone verify that this is the knock sensor on a EJ25? Ive checked it with a mulitmeter and ther's no continuity but I want to make sure I'm checking the right thing. Have a Sweet Day! Attached Thumbnails

2007-01-02, 08:55 PM	#2
sperry The Doink Real Name: Scott Join Date: Nov 2002 Location: Portland, OR Posts: 20,335 Car: '09 OBXT, '02 WRX, '96 Miata Class: PDX/TT-6 The way out is through	I can't say I've ever found my knock sensor... but you can check here for the service manuals: http://www.seccs.org/tech/ __________________ Is you is, or is you ain't, my con-stit-u-ints?

2007-01-02, 10:17 PM	#6
sybir The Don Real Name: Aaron Join Date: Oct 2003 Location: Sacramento Posts: 3,097 Car: '97 Legacy / '05 FXT Class: low	That looks like it, but it's hard to tell becuase of the various parts that look like they're loose (I can't locate it effectively). I've got an EJ25 too, but my throttle cable doesn't run perpendicular like that.... I beleive the knock sensor is behind the manifold and on the right side of center when looking into the engine bay from the front, and that definitely lookslike it (a single bolt runs through it and into the block). Additionally, that connector looks like the right one. Sorry I can't be of more help, I got lazy and had the shop I was working for at the time fix it when mine went. __________________ Tact is for people who aren't witty enough to be sarcastic.

2007-01-03, 07:29 AM	#9
MPREZIV Token Real Name: Le Stig Afrique? Join Date: Jun 2005 Location: sitting next to a big yellow box Posts: 3,589 Car: 2001 Impreza 2.5 RS Class: 05 TDSP No, I won't work on your car. F your car*	That part circled in the picture, is 100% for sure the knock sensor! And I wasn't eating chicken... we had spaghetti for dinner last night. __________________ "...these condoms have a topical anesthetic to reduce sensitivity, so you can last longer. What a paradox. You can't feel a thing, but you can f*ck for HOURS..."

2007-01-03, 07:42 AM	#11
MPREZIV Token Real Name: Le Stig Afrique? Join Date: Jun 2005 Location: sitting next to a big yellow box Posts: 3,589 Car: 2001 Impreza 2.5 RS Class: 05 TDSP No, I won't work on your car. F your car*	You've never been down south... you can deep fry ANYTHING!!!! That knock sensor is supposed to have a resistance from one of the two pins to the inside of the housing where the bolt goes through, once you remove it from the block. I don't recall what pin, or what the resistance spec. is tho. Lemme look through some svc. manuals I have, and get back to you. Oh, and the knock sensor is the ONLY code you're getting? Most of the time they won't actually turn on the CEL... __________________ "...these condoms have a topical anesthetic to reduce sensitivity, so you can last longer. What a paradox. You can't feel a thing, but you can fck for HOURS..." Last edited by MPREZIV; 2007-01-03 at 07:44 AM.*

2007-01-02, 09:35 PM	#3
khail19 EJ205 Real Name: Khail Join Date: Dec 2002 Location: Reno, NV Posts: 1,769 Car: 2016 VW GTI Meets? We have meets?	Where's Cory when you need him?

2007-01-02, 09:56 PM	#5
khail19 EJ205 Real Name: Khail Join Date: Dec 2002 Location: Reno, NV Posts: 1,769 Car: 2016 VW GTI Meets? We have meets?	Damn him and his need to fit the stereotype.

2007-01-02, 10:58 PM	#7
coronan n00b Join Date: Nov 2006 Location: Reno Posts: 9 Car: 99 OBW	Ok Im gaining conficence. I folded the throttle body out of the way to gain access to the connector. Yes its under the throttle body pullies, behind the intake manifold, right of center on the top of the block. You can see the hydraulic clutch to the rear. So then the manual says if it does not have continuity the unit is working. It DOES NOT. What are the other common causes for this sensor to trip??? I installed an underdrive pully about a week before the check engine light first showed up. If reset the light comes back in 3 or 4 days. I'm sporting 110,000 miles but the motor sounds good and hasnt exhibited any loss in power. Any experience, Anyone???

2007-01-03, 08:16 AM	#12
MPREZIV Token Real Name: Le Stig Afrique? Join Date: Jun 2005 Location: sitting next to a big yellow box Posts: 3,589 Car: 2001 Impreza 2.5 RS Class: 05 TDSP No, I won't work on your car. F your car*	I looked in Alldata, but I couldn't find anything on spec. or which pin is which. I do know that there is supposed to be continuity between one of the connector pins, and the metal inner body of the sensor. __________________ "...these condoms have a topical anesthetic to reduce sensitivity, so you can last longer. What a paradox. You can't feel a thing, but you can f*ck for HOURS..."

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