PO 325, anybody have a knock sensor wire diagram?

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PO 325, anybody have a knock sensor wire diagram?

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Mazda Forum >> Mazda Vehicles >> Mazda Millenia >> PO 325, anybody have a knock sensor wire diagram?

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PO 325, anybody have a knock sensor wire diagram? - 10/28/2006 10:07:15 PM

Richard

Posts: 54
Joined: 10/24/2006
Status: offline

One last problem, I keep getting CEL code PO325, after I erase all codes the next time I start it it comes right back. Does anyone have the wiring code for the connector so I can measure impedence, volts, etc. I have a collection of different size piezo transducers and maybe I can "fool" the ecm to think the knock sensor is alive and happy. I understand on the 97 2.5L engine they are a real PIA to remove & replace.
Thank's to all,
Richard.

Post #: 1

RE: PO 325, anybody have a knock sensor wire diagram? - 10/29/2006 12:08:28 PM

keninn

Posts: 389
Joined: 9/2/2005
Status: offline

we have 2 99 2.3's, and i have the wiring diagrams for the 99's. however, i question the fooling of the knock sensor to the ecu. what if you have a defective distributor, and you are getting too much advance, or something like that. if you fool the ecu, you might get holes in the pistons. iirc, the only real beyatch on getting the sensor out is the clearance, i think a special socket is needed. getting to stuff on the 2.5 is cake compared to the 2.3.

(in reply to Richard)

Post #: 2

RE: PO 325, anybody have a knock sensor wire diagram? - 10/29/2006 12:49:47 PM

Richard

Posts: 54
Joined: 10/24/2006
Status: offline

Hello and Thank's for getting back to me. I am an avionics engineer and familiar with electronics(I upgrade navigation systems on airliners and military aircraft) However since the disaster on 9/11 the airlines and the military are parking their older planes in Arizona, the F-14 Thomcat has been completely taken out of service. The firm I worked for (14 years) closed the doors after the Christmas party last year so money is very tight right now. The engine is not pinging or knocking on 87 octane. What I am worried about is another code is sent and I won't know about it, plus the CEL being on all the time is annoying. I will be very careful and if I don't think it wont work I will not try it. This is not a permanent repair, once I have earned some more cash I will have the proper sensor installed. Thank You for your concern, if you still feel uncomfortable I understand.
Best Regards,
Richard.

(in reply to keninn)

Post #: 3

RE: PO 325, anybody have a knock sensor wire diagram? - 10/29/2006 3:14:57 PM

keninn

Posts: 389
Joined: 9/2/2005
Status: offline

it is your car, you can do what you want. from past experience, the sensor has this "stuff" inside it, and over time, and lots of heat cycles, it kinda leeches out. then the sensor becomes more sensitive. in my 99 manual, here is what it says.

P0325 knock sensor 1 circuit malfunction

detection condition-input voltage from knock sensor is below 1.25v or above 3.75 v after engine start

possible cause

knock sensor malfunction
knock sensor installation incorrect
open or short circuit in wiring from PCM terminal 3S to knock sensor terminal A

the next steps have to do with the ngs tester, and there are several trouble causes/effects, way too numerous to type in. a couple of the big chunks are:

2. does knock sensor connector or PCM connector have poor connecton? repair or replace sensor, clear codes.

3. disconnect knock sensor connector. is there continuity between connector terminal A and PCM terminal 3S?

if no, repair or replace harness.
4. is resistance of knock sensor ok? however, there are no specs on resistance value.

checking the 2.3 codes, the knock sensor code is identical, and the troubleshooting is also. however, the 2.5 shows only a single lead coming off the sensor, the 2.3 shows 2 leads.

from what i see, and past experiences on other cars, there is not much you can do except replace. overtorqueing the sensor can make it very sensitive, but i have never heard of it getting more sensitive if it was an original install, only after replacement. good luck, and remember, this is all from my 99 manual. there probably is no difference, but you never know.

(in reply to Richard)

Post #: 4

RE: PO 325, anybody have a knock sensor wire diagram? - 10/29/2006 3:26:44 PM

Richard

Posts: 54
Joined: 10/24/2006
Status: offline

Thank's for your help, Now I have to find/buy a wiring diagram to identify terminals, and and connector pins. Or I might just drive it until I can get a new sensor, it seems to run fine.
Best Regards,
Richard.

(in reply to keninn)

Post #: 5