daja Posted September 15, 2004 Share Posted September 15, 2004 My ongoing saga.... Finally read the proper code from ECU. P0325. I decided first on replacing the fuel filter since it was cheap and easy. WOW, what a difference! Car runs so much smoother and acceleration is noticably better. I noticed how bright and shiny the new filter thing is. Car has 125k and is 4 years old. I do not recall this being changed, ever! Isn't it suppose to be at every 24k service? CEL came on again. Thought I had it licked. P0325 is a knock sensor malfunction. Is this one of those codes that actually means what it says? Or can it be related to anything else? I have never modified my knock sensor. I've read and followed the advice about cleaning and checking resistance and wire continuity. Need advice. I love my Sube ('00 Forester), but I'm starting to have dreams with bright yellow lights Quote Link to comment Share on other sites More sharing options...
BillAileo Posted September 15, 2004 Share Posted September 15, 2004 Do you have access to an ohm meter and feel comfortable using it? If so, there is an interesting article on diagnosing Subarus at http://www.babcox.com/editorial/ic/ic30332.htm That suggests checking out the knock sensor using an ohmeter as follows: The Knock Sensor will have a DTC of P0325. If the harness appears intact, test the sensor at its disconnected harness connector. Check resistance between terminal 2 and ground. The Knock Sensor should have at least 400 k/ohms of resistance. Bill Quote Link to comment Share on other sites More sharing options...
99obw Posted September 15, 2004 Share Posted September 15, 2004 FWIW, I had this code recently, replaced the knock sensor, no more MIL. Quote Link to comment Share on other sites More sharing options...
JohnnyB Posted September 15, 2004 Share Posted September 15, 2004 I too recently had this code for the knock sensor. After searching the board, I tried the easy stuff first, replaced fuel filter (needed it anyway), fuel injector cleaner and used some higher grade gas to no avail. Finally replaced the sensor, no more CEL. Quote Link to comment Share on other sites More sharing options...
Phillip Posted September 15, 2004 Share Posted September 15, 2004 Do you have a digital ohm meter? If so, disconnect the electrical connector between the knock sensor and the wiring harness and check the resistance. It should be 400K -560K. If not, replace the knock sensor. If within range, disconnect the electrical connector at the ECM (on the floorboard on the passenger side and check the resistance between the #3 terminal and ground. If significantly different than your reading at the knock sensor, you've likely got a broken wire or bad connection. E-mail me if you need to know where the electrical connectors are. It's probably a bad knock sensor, but no sense in replacing a part if not necessary. I've got a good used OEM knock sensor that was installed but not used if you want to save some money. My ongoing saga.... Finally read the proper code from ECU. P0325. I decided first on replacing the fuel filter since it was cheap and easy. WOW, what a difference! Car runs so much smoother and acceleration is noticably better. I noticed how bright and shiny the new filter thing is. Car has 125k and is 4 years old. I do not recall this being changed, ever! Isn't it suppose to be at every 24k service? CEL came on again. Thought I had it licked. P0325 is a knock sensor malfunction. Is this one of those codes that actually means what it says? Or can it be related to anything else? I have never modified my knock sensor. I've read and followed the advice about cleaning and checking resistance and wire continuity. Need advice. I love my Sube ('00 Forester), but I'm starting to have dreams with bright yellow lights Quote Link to comment Share on other sites More sharing options...
daja Posted September 16, 2004 Author Share Posted September 16, 2004 I followed the sensor wire further along and notice it does a 120 degree turn into another set of wires. At this junction the electrical tape seemed very gummy from rubbing. I turned the wire as much as I could opposite and it seems to be working. I looked around and there are many places where the wires seem to be pulled back and potentially have an internal break caused by engine vibration. Are there many reports of open circuits causing malfunctions in Subes? I find this odd and hope it is not intentional to milk money from people. Many thanks to all for the advice Quote Link to comment Share on other sites More sharing options...
avk Posted September 16, 2004 Share Posted September 16, 2004 Inside the harnesses, wires are joined simply by crimp connectors, of the same kind as at the terminal pins. But to break the joint, someone had to pull on the harness hard enough. Did the Forester have any work done on the drivetrain? The diagnostics in the Babcox article cited by Bill is straight from the FSM. Quote Link to comment Share on other sites More sharing options...
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