Knock Sensor Question

[J A Blazer]

2000 4cyl OBW, 130K. About once a month my CEL comes on; I pull the code; its a 328, i.e. knock sensor. I reset and all is well for about another month or so. What exactly is this CEL telling me? That the sensor needs to be replaced? I did that about 35K ago, with OE part. Or is some other condition generating this code?

[cobcob]

Check your sensor resistance to ground... Should be around 4.2K iirc.

[MorganM]

Here are the different error codes for knock sensor I'm not sure what "high imput" means

P0325

Knock Sensor Circuit Malfunction

P0327

Knock sensor circuit low input

P0328

Knock sensor circuit high input

 

P1325

Knock Sensor Circuit Low Input

[idosubaru]

While making sure it's not something else, EJ knock sensors typically need replaced with age/mileage. The base of them gets rusty/corroded and the rubber begins to crack and degrade. Might be able to just remove, clean it up and get it to go away. Or replace.

[cobcob]

literally 10 minutes after posting my above comment my 2000 2.5RS threw a P0325

[Olnick]

Timing is everything, right cobcob? (But that's kinda spooky!!!)

[EVOthis]

literally 10 minutes after posting my above comment my 2000 2.5RS threw a P0325

 

 

Yea thats creepy...

[cobcob]

She's just having a hissy fit because I'm taking my time installing her new exhaust & crank pulley. She'll get over it soon enough.

[Fairtax4me]

Some weird ju ju goin on there.

 

High input would probably mean the voltage signal the ECU is receiving is higher than it thinks it should be. Check resistance of the sensor and check reference voltage at the connector.

[mtskibum16]

So what would the 325 mean then? That's the code I'm getting after putting the car back together after headgasket replacement and it's definitely running like the sensor is bad (the last one I fixed had a bad knock sensor and felt the same....kind of sluggish when accelerating). So do I just need to change the knock sensor?

[Fairtax4me]

So what would the 325 mean then? That's the code I'm getting after putting the car back together after headgasket replacement and it's definitely running like the sensor is bad (the last one I fixed had a bad knock sensor and felt the same....kind of sluggish when accelerating). So do I just need to change the knock sensor?

 

It's pretty easy to break these things apparently. A new sensor may be needed in your case if it was removed while the work was being performed. When installing the sensor if too much force is applied to the bolt it will crack the unit resulting in an open circuit.

 

Don't know what I was thinking in my last post in this thread. Reference voltage to a knock sensor...

 

 

Where's the brain fart icon? Need one of those in that smiley list.

[mtskibum16]

IIRC I torqued it to the spec in the manual. I might be making that up though..... . Don't remember. So just to see I tested my other "bad" one and it shows 500 kohms. What's the spec - I thought they'd short.