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Knock senor code 0325 won't go away.


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OK here's one that probably has only happened to me but on the off chance there's someone out there with as bad of worse luck than I here goes.

The problem is a 1996 Impreza 2.2 auto. The previous owner told me he replaced the engine with another 96 2.2 and that it had a knock sensor code with the CEL on all the time. The CEL and code are verified, the engine replacement is his word. What he failed to mention was the AT temp light flashing @ every start up, 16 times.

I replaced the knock sensor and cleared the code with my scanner. On start up the AT lite flashed and the CEL came on. Plugged the scanner back in 0325 is back. Left one part out my scanner can also read tranny fault codes. It has a option for 4-spd trans for these cars. When the tranny code is scanned it comes back as the knock sensor code!?!?! There's something not right here and I know it's not the scanner. I just used it yesterday on my daughters van. As well as my wifes car last week. Any suggestions?:-\

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Check engine light was on when you got it or from the beginning?

 

The knock sensor you replaced - was the rubber cracked and aged looking?

 

Did you use a Subaru Knock sensor?

 

I would make sure of the following:

1. The knock sensor is positioned properly - it's supposed to be installed a specific angle, documented in the FSM.

2. The bolt hole and threads are clean.

3. The bolt it torque properly.

4. The knock sensor connector is fully seated and not corroded, broken, etc.

 

Assuming none of that is the cause, then verify continuity between the knock sensor plug and the ECU. That will actually be relatively easy. That will verify that the wiring from the plug to the ECU is good.

 

ECU is under the passengers side kickboard/carpeting. pull that up and figure out which pin is the ECU input. Check continuity between that wire and the knock sensor harness on the engine.

 

There's not much too it other than that - a very simple sensor and one wire running to the ECU.

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Gary, The CEL was on when I got it. The sensor I replaced had cracks and was old. I did not use OEM to replace. Figured simple sensor didn't think it would matter. I think the replacement was a Bosch, not a fly by night outfit.

I'll recheck the angle and the ecu. I've got 560K ohm between the harness plug and ground. The connector is good and the wires I can see look intact.

Cleaned the bolt hole and bolt used anti-seize on bolt. Thanks

Edit: Gary the engine I mentioned to you in my pm. Bubbles in the overflow runs like crap. No surprise.

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aftermarket O2 and Knock sensors can be problematic, even from "good" companies. can you swap one from a known good engine if you have multiple engines/subarus?

 

if you still have the old sensor, sometimes you can "fix" them by cleaning them up and filling the cracked rubber with RTV - then reusing.

 

personally i'd pull one off another car that's working right and see what happens.

 

you say the engine is running like crap? then maybe something is causing this other than knock sensor related.

 

if you're still trying to get that impreza running that has TB - if the TB doesn't go away and is really bad you can remove the rear axles and run it FWD that way - or unplug duty C just to make sure it's "locked".

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[...]if you're still trying to get that impreza running that has TB - if the TB doesn't go away and is really bad you can remove the rear axles and run it FWD that way - or unplug duty C just to make sure it's "locked".
If the car being discussed in this thread has torque bind, then there's a fair chance that the trans code will relate to the C duty solenoid (blink code "24").
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Update: The sensor angle was wrong thank you Gary. The CEL is now off.

No codes are stored. This thread is now about the AT light flashing 16 times on start up. Correct me if I'm wrong but the AT light will flash if there was a problem detected during the last use of the car. So if the car is started, light flashes, car is turned off, then restarted without moving AT light should not flash. Right? This car the light does flash 16 times @ every start up. I'm going out to check the connection for the trans and find the connector for the TCU. Thanks to all who responded you people are great! Keep em coming!

 

FYI: The engine with bubbles in the overflow and running like crap is NOT the same car.

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if you're still trying to get that impreza running that has TB - if the TB doesn't go away and is really bad you can remove the rear axles and run it FWD that way - or unplug duty C just to make sure it's "locked".

 

This is the same car, the way the AT light acting I'm not sure about the TB anymore. It's not registered so I'm a little hesitant about driving it around to test for TB. I'm going the check a few more things before I take a chance driving it.

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[...]Correct me if I'm wrong but the AT light will flash if there was a problem detected during the last use of the car. So if the car is started, light flashes, car is turned off, then restarted without moving AT light should not flash. Right? This car the light does flash 16 times @ every start up.
The 16 flashes indicate an electrically-related problem was detected, and that there's a code stored. That means the defect can be detected even if the car isn't moved.

 

 

I'm going out to check the connection for the trans and find the connector for the TCU.[...]
The B82 diagnostic connector is the same one that has pins for ABS diagnosis. If it's never been used before, it may still be taped to the under-dash harness. It's a 6-pin, usually black, and should have two "ground probes" (separate wires with pins that will fit B82) that are also usually taped.
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I just came back from a short test drive. This car has TB ya can feel even on turns that are not real tight. Also the ABS light came. The more I get into this car the more I think that I have a parts cars here. I can use the engine for my Legecy Outback and the car for parts for Mrs. Screwbaru's Impreza! Must be the Duty-C. Thanks for the tips OB99W.

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Update: The sensor angle was wrong thank you Gary. The CEL is now off.
awesome, glad we covered you on that one.

 

nice job - you changed the title and all!

 

the ABS is probably rusted/corroded sensors from sitting so long. not a big deal anyway - they'll still work as non-ABS brakes anyway. those sensors are expensive and usually a pain to get out - the bolt will likely shear off due to rust and you'll need to drill it out or get creative. what i usually do is just drill a and tap a smaller bolt hole in the stud in the hub and use a small bolt to hold the sensor in place. no load so it doesn't matter that the bolt is smaller...i'm sure they'll rust in place too over time!

 

now the torque bind. sounds like it's bad. did you try the FWD fuse - it may run fine with that in place. if not - then i'd just pull the rear half of the driveshaft out (very easy - either 12mm nuts and it comes out) and disconnect the duty C solenoid. that may require cutting the wire, can't recall if there's an external connector, but i think there is. i always just cut the wire since i splice a switch in place to manually control it anyway. that will give you FWD and no driveline problems.

 

in the end - you can swap the rear extension housing (duty C and clutches) without dropping the transmission, so it's not a horrific repair to do - it's possible.

 

by the sounds of it though i think i'd rather run it FWD for a few months and see how many issues it has.

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As a matter of fact I just came back from yet another outlaw test drive with the fuse in the FWD holder. It still feels like it's still binding on turns and the thump,thump,thump at the rear tire is still there (failed to mention that before) the guy who had this car before me is a real hacker who knows what he did or didn't do to this poor Imp. I had bought it for the engine but it's such a nice looking car I thought maybe I'd run it instead. I'm definitly having seconds thoughts now. It's getting hot and very muggy now, I'm about ready to quit for today. Thanks again all. I'll update this in the future but right now I'm leaning towards parts car.

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remove the rear half of the driveshaft, cut the duty C wire (one wire) and run it in FWD. don't know the car but it might be good for a long while with that 30 minutes of work?

I hate when people confuse me with facts. Does that involve removing the drivshaft too? That thing probably hasn't been off since 1996. I really want to get my Outback going again. This is the kinda thing that gets me off my dead rump roast and doing something! I'm going out to finishing pulling the motor on the Outback and take a peek at that Impreza's trans, maybe,later.:confused:

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I hate when people confuse me with facts. Does that involve removing the drivshaft too? That thing probably hasn't been off since 1996. I
what's confusing? yes you will remove the rear half of the drive shaft (eight 12mm bolts - 4 on each end)

 

1. cut one wire for duty C

2. remove driveshaft.

3. done -enjoy your FWD soob

 

de-power Duty C (usually involves cutting one single wire, that's it). once you know which wire, it takes 5 seconds to cut it.

 

with that done your car is now "locked" in 4WD until you splice that wire back together. but who cares, it's already locked with significant torque bind so big deal.

 

now - with it locked you'll want to drive in FWD - so remove the driveshaft. i've removed it ton of them - it's easy. 12 mm wrenches.

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Gary, I'm half joking about being confused. You give good advice and I appreciate it. I'm focused on my Outback now, if by Sat night it looks like it's not going to happen then I'll turn to the TB'd Impreza and cut that wire. I'm not big on servicing ATs. When it comes to ATs I usually just replace em.

Thanks, Jordan

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