Help with CEL P0325 - Knock Sensor - Bank 1

[zgendron]

Hi,

My girlfriend's 98 I-30 with 99K recently had the CEL appear. I took it to Autozone, and its a P0325, which appears to be a Bank 1 Knock Sensor.

According to AZ, the part is about $170. However, just because the CEL appears, doesn't mean the knock sensor is broken, right? Any help would be greatly appreciated.

Oh, and we're up in Boston, MA. The CEL appeared about a week ago, and has stayed current.

[CJQ45]

Theres gotta be more to it that just that. A knock sensor will not trigger a CEL, it will only store it. It will retard the timing to slow the accleration. There should be another code in there that's triggering the CEL.

99I30 - most probably a EVAP problem. Maxima's have similar problems (vent control vavle). But check it with the consult or scanner.

CJ

[zgendron]

CJ,

Thanks for the quick reply. Just so I understand correctly, this code cannot throw a CEL on its own. There needs to be another code stored in there?

I'll try taking it to another Autozone and have them rescan it. I don't have a scan tool. I'll also try resetting the PCM and see if the code is still there.

- Zack

[CJQ45]

The best thing to do is to reset the CEL and see if it comes back - it may be on just because of a loose gas cap. The KS sensor does not throw the CEL on its own. If it comes back - take it to autozone and rescan.

CJ

[DAEDALUS]

The knock sensor can indeed cause a CEL. Clear it and see. It will probably come back though, often ECUs have a probation period for borderline faults. If the CEL is lit the cause is severe and/or persistent.

[metaverse3]

You're thinking of old school nissan OBDI Pre-fed days...OBDII will trigger knock sensor regardless of car make/model. Clearing the code will probably bring it back...worth a try, but, there is a reason why it shows up...

This is what you will need and it costs around $120 average: http://catalog.worldpac.com/ea...ensor from what I can see. Labor is what can make it costly.

[CJQ45]

I double checked the FSM for a 97 Q, which has an OBDII system. The Knock sensor will NOT tigger the MIL by itself. See attachment from FSM.

I tried to insert the picture - but was unsuccessful. Its in the EC section p. 189 (KS). It states in bold print that the KS will not trigger the MIL.

CJ

[metaverse3]

You're comparing systems that are not from the same car. What would you like me to say ? The CEL in the dash that clearly states you have a knock sensor failure is wrong since a manual from a 97Q45 obdII states knock sensor will not trigger MIL. Nissan manuals are never accurate 100%. For e.g. a 1992-94 cali-spec maxima has an injector leakdown circuit which detects and triggers code 53. Has any cali spec owner ever seen this , no. I personally own a cali-spec 92SE with clearly dribbling injectors that caused a hard start 2 years ago which I found by doing a fuel system pressure test over a week. Not even a stored code, not while driving with a snap-on handheld, not while doing a injector power balance test.

Knock sensor transmits voltage to the ECU that variates from the piezo electric element detecting vibration and converting it to voltage. You can cheat the knock sensor by putting a resistor that clones the normal operating ohms on the factory harness. This will let the car coast 24/7 fooling the ECCS into thinking the engine is always optimum and not to adjust fuel mixture, timing, with respect to knock sensor readings. However, this is not a long term solution..can be short term test bed. Look into the VQ history..they have known problems with knock sensors.. Look here to get an idea of a knock sensor replacement: http://www.motorvate.ca/mvp.php/507 Just be glad you are not experiencing the known issue with airbag modules on that car... $600+ for each..and dealer won't even touch it nor will infiniti corporate, even with extended warranties.despite being a safety issue.

[zgendron]

Thanks for the added information.

Is there a test I can perform on the knock sensor to determine if the problem is the sensor itself, or something else? Can I measure the voltage or resistance across the sensor?

Additionally, do any of you guys have either the Nissan or Inifiiti factory service manual on CD or DVD? Anyone willing to burn it for me for a few bucks. I bought one on Ebay once, and it was a total waste of money.

Thanks Guys, Zack

[metaverse3]

Attached is some screencaps of a 1998 VQDE manual..same engine in your I30..hope it helps

(It is a winrar self executable...scan it for viruses if you are unsure)