P0325 Error Code

[Mikelowe93]

Howdy. I've lurked here for a long time but IIRC, this is my first post. Please pardon any transgressions. A few of you may know me as Mikelowe93 in the Miata Forum with my 94 turbo Miata. A few of you may know my cousin Dave Poedel in AZ who goes by Padre Dave on some PT sites. But I digress....

This morning, my PT lit its check engine light on the way to work. Of course I pulled over for a bit and did a cursory check of the worst case stuff like oil level, coolant, loose gas cap, etc. Things looked OK so I drove to work.

During lunch, I did a search here and learned how to pull codes. I did the routine and got a P0325 OBD-II error code. Much thanks to the folks here for the OBD-II info (specifically a Canadian aliased as Punch).

Per http://www.ptcruiserlinks.com/forum/...?TOPIC_ID=4271 ,

P0325 = Knock Sensor 1 Circuit (Bank 1 or Single Sensor).

A search of this forum turns up only the page linked above (of course).

OK then. Knock Sensor 1 Circuit (Bank 1 or Single Sensor). Well, that's very descriptive. I can think of several possibilities.

1. Is the circuit fried?
2. Did I get knock once too often?
3. Did I get a bad tank of gas?
4. Is the circuit not fried but working on it?
5. Is the sensor just unplugged / loose?
6. Insert other idea here.

I'll try to offer some info and answers. The weather was cool but not cold. It's seen <40 degrees F lately. It was maybe 60 F this AM. The car is a 5-speed GT with nearly 8000 miles on it. It was built on March 03, 2003 but it was held for quite a while before delivery in May. It was used/dynoed about 45-46 miles. I think I was one of the guinea pigs for the improved ECU programming I've heard rumors about.

The car has been on 93 octane since the first fillup. The engine performance has been great since then and is still fine today. It's loving the cool air here. Yes even Texas gets cool eventually. The car's been on Mobil 1 for a while.

It never showed any signs of problems when the GF and I thrashed it hard in the Arkansas mountains a month ago. That trip is the only real thrashing the car has received. I usually use the Miata for autocrossing/track running/thrashing/etc. The PT is a great tire hauler!


Following the numbers above:

1. Is it fried? I hope not. I really yearn to deal with the dealership. (satire alert) It's a good thing my office is a block from Ron Carter Chrysler/Hummer/Chevy/everything in Alvin, TX. Does anyone local know if they have a clue? I only know of one other GT owner around here (Steve03GT, IIRC).

2. The car's been on 93 octane exclusively. I have never heard knock. I know what it sounds like since I have a (usually) highly tuned & boosted Miata with a turbo kit (FM II for those in the know). I know knock well and I know how to stop it. Of course, the PT is so very quiet vs. the Miata.

3. Bad gas? Hmm, it's about time for a transition in gas formulation. This is the first cool weather for the PT since I got it in May. The car still runs/boosts well but I didn't go flat out today since the car isn't 100%. It's not in any limp-home mode. I've used this one gas station a few times. It's a regular Shell station. I stay away from non-major-brand places.

4. I hate transitory sensor issues. Ugh!

5. Where is/are the knock sensor(s)? I've been under the car a few times but I've never hunted specifically for a knock sensor. My Miata has its aftermarket kit knock sensor on an engine mount. Does Chrysler do something similar with PTs? I guess I should get a service manual.

6. Input help here.

Any help is appreciated. A search didn't help me here. I really was hoping my PT would have better reliability than usual for Chrysler. I really hope this is a fluke thing. My girlfriend is really getting to like the PT and she wants one. I can't have her in an unreliable car though.

[COP TZER]

Is the vehicle bone stock?? By the way welcome to the forum. I'm sure enough people will offer good advice.

[Mikelowe93]

Oh, I have a bunch of pics of the PT for those interested. See http://www.imagestation.com/album/pi...?id=4290174365 and http://www.imagestation.com/album/?id=4288516833 . Is there a way to create a short weblink with this software? I don't see it right now.

Imagestation may ask you to log in as a member by clicking on a link. You are a member. You just don't know it. Your login and password are both 'qwerty93' (no quotes). My other albums (mostly Miata stuff) can be found from those two albums. Enjoy!

[Mikelowe93]

quote:Originally posted by COP TZER

Is the vehicle bone stock??

Doh! How could I forget mods! It's nearly bone stock. I've removed the two air silencers in the air box. I didn't remove the one near the turbo. I already have a car that goes whoosh all day long. I also removed half the hood weatherstripping but I don't think that does anything.

Good question.

[MX-5]

There is only one knock sensor. It's on the engine block, just below the starter.
Here's the info from the Mopar parts server:
SENSOR, Knock
#56028 563AA

It will be a warranty repair.

Diagnosis with a scanner will tell if it's working. Light tapping on the block will retard the timing. A scan tool will show the datastream.

From the 2003 PT service manual, page 8I-11:
KNOCK SENSOR
DESCRIPTION

The knock sensor is bolted to the cylinder block.
The knock sensor is designed to detect engine vibration
that is caused by detonation or preignition.

OPERATION
When the knock sensor detects a knock in one of
the cylinders, it sends an input signal to the PCM. In
response, the PCM retards ignition timing for all cylinders
by a scheduled amount.
Knock sensors contain a piezoelectric material
which constantly vibrates and sends an input voltage
(signal) to the PCM while the engine operates. As the
intensity of the crystal’s vibration increases, the
knock sensor output voltage also increases.
The voltage signal produced by the knock sensor
increases with the amplitude of vibration. The PCM
receives as an input the knock sensor voltage signal.
If the signal rises above a predetermined level, the
PCM will store that value in memory and retard
ignition timing to reduce engine knock. If the knock
sensor voltage exceeds a preset value, the PCM
retards ignition timing for all cylinders. It is not a
selective cylinder retard.
The PCM ignores knock sensor input during engine
idle conditions. Once the engine speed exceeds a
specified value, knock retard is allowed.
Knock retard uses its own short term and long
term memory program.
Long term memory stores previous detonation
information in its battery-backed RAM. The maximum
authority that long term memory has over timing
retard can be calibrated.
Short term memory is allowed to retard timing up
to a preset amount under all operating conditions (as
long as rpm is above the minimum rpm) except WOT.
The PCM, using short term memory, can respond
quickly to retard timing when engine knock is
detected. Short term memory is lost any time the
ignition key is turned off.
NOTE: Over or under tightening affects knock sensor
performance, possibly causing improper spark
control.



INSTALLATION - 2.0/2.4L
The knock sensor bolts into the side of the cylinder
block in front of the starter under the intake manifold.
(1) Install knock sensor. Tighten knock sensor bolt
to 22 N·m (195 in. lbs.) torque. Over or under
tightening effects knock sensor performance,
possibly causing improper spark control.
(2) Attach electrical connector to knock sensor.
(3) Connect the negative battery cable.


I've been on the Miata forum since 1999. Mine is a black 94 with the Jackson Racing supercharger, big boost kit, and NOS.

[Punch]

quote:Originally posted by Mikelowe93

Oh, I have a bunch of pics of the PT for those interested. See http://www.imagestation.com/album/pi...?id=4290174365 and http://www.imagestation.com/album/?id=4288516833 . Is there a way to create a short weblink with this software? I don't see it right now.

Imagestation may ask you to log in as a member by clicking on a link. You are a member. You just don't know it. Your login and password are both 'qwerty93' (no quotes). My other albums (mostly Miata stuff) can be found from those two albums. Enjoy!

read the faq section above to the right, on how to post pics, and learn from my errors, when using imagestation, delete the last .jpg from you picture.

punch

[Mikelowe93]

There was no check engine light this morning or during lunch. The code is still saved in memory. I assume this code will stay in memory until the dealership clears it.

Thanks for all the advice so far.

[bobs turbo pt]

welcome to the board!![8)]