P0327 - Knock Sensor code

2005 Legacy GT LTD throwing code P0327 - Knock Sensor 1 Circuit Low Input.

 

Symptoms were: Engine began notably hesitating, dash lit up (CEL and flashing CRUISE). Aborted our trip and drove it gently back home, about an hour on the road. By the time it was parked, there was a smell of maybe burning rubber and some white smoke which dissipated pretty quickly. Temp gauge was normal, but engine seemed quite hot. Oil and coolant levels normal.

 

Car just had a fresh oil change and topped off fluids. Has been running fine otherwise.

 

I searched the forum to find Knock Sensor replacement may be pretty common. Is that a part swap my local (non-Subaru) mechanic can do? Should that solve the problem?

I'd look into the cause of the smell and smoke, not just replace the knock sensor. Spontaneous combustion is not a typical failure mode. That said, the actual replacement should be no more than an hour of labor.

It likely needs the knock sensor replaced, I’d make sure it’s replaced with an oem sensor. It’s a fairly easy job to replace it. As far as your bit of smoke and smell, if you just topped off the fluids it’s probably a little bit of spill that finally made its way to the exhaust and is likely in no way related to your knock sensor issue. The knock sensor itself produces a very small amount of voltage so it couldn’t burn anything up. But a thorough visual inspection should be made before coming to any conclusions.

It's plausible the smell and smoke might be from a brand new power steering pump/belt just installed as well, or the topped off fluids. I'll definitely keep an eye on it, but good to assume it's unrelated.

 

I ordered an OEM knock sensor, we'll replace it and see if that solves the issue. Thanks all!

I wonder if there's an oil leak that's pooling where your knock sensor is that killed it (from the pcv?), I thought I remembered reading about that happening to someone, not sure.. I'm not sure why I'm adding the pics below if a mechanic will be replacing it, but oh well, I'll post them anyway for future reference. There's some funny business with the cord angle too

I'm not sure why I'm adding the pics below if a mechanic will be replacing it, but oh well, I'll post them anyway for future reference. There's some funny business with the cord angle too

 

Actually, thanks for that. I have a few of those pages bookmarked, as we were trying to figure out of this part-swap is enough of a no brainer to do in the driveway. If not, I'll take it to my local (non-Subaru) guy.

 

I'm almost certain the other symptoms were unrelated.